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Ye Y, Huang H, Li H, Wu G. Role of chemical groups in regulating membrane tension of mBMSCs under stretch stimulation. Colloids Surf B Biointerfaces 2025; 252:114644. [PMID: 40132336 DOI: 10.1016/j.colsurfb.2025.114644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2025] [Revised: 03/08/2025] [Accepted: 03/17/2025] [Indexed: 03/27/2025]
Abstract
As a crucial mechanobiological regulator, the tension of the cell membrane plays a vital role in governing cellular adhesion, proliferation, and differentiation processes. Additionally, it displayed a dynamic response to mechanical microenvironmental changes. This research systematically examines the mechanoresponsive behaviors of mouse bone marrow mesenchymal stem cells (mBMSCs) that are cultured on poly(dimethylsiloxane) (PDMS) substrates which are functionalized with methyl (-CH3), amino (-NH2), and carboxyl (-COOH) groups. Under both static and stretching conditions, it is found that compared with the -CH3 surface, static culture on the -NH2 and -COOH functionalized surfaces significantly promotes the proliferation of mBMSCs and upregulates the expression of extracellular matrix adhesion-related genes, especially focal adhesion kinase (FAK) and integrin β1. Morphometric analysis reveals that there are concomitant increases in the cell spreading area and the number of pseudopods on these modified surfaces. Mechanical stretching stimulation not only amplifies these cellular responses but also leads to more uniform FAK distribution. The assessment by atomic force microscopy (AFM) shows that both chemical functionalization (-NH2/-COOH) and stretch stimulation reduce the deformability of the cell membrane, and the -NH2 modification exhibits a greater membrane-stiffening effect than -COOH.
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Affiliation(s)
- Yunqing Ye
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, PR China; Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou 510006, PR China
| | - Haoyang Huang
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, PR China; Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou 510006, PR China
| | - Hong Li
- College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, PR China
| | - Gang Wu
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, PR China; Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou 510006, PR China.
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Breitenstein P, Visser VL, Motta SE, Martin M, Generali M, Baaijens FPT, Loerakker S, Breuer CK, Hoerstrup SP, Emmert MY. Modulating biomechanical and integrating biochemical cues to foster adaptive remodeling of tissue engineered matrices for cardiovascular implants. Acta Biomater 2025; 197:48-67. [PMID: 40118167 DOI: 10.1016/j.actbio.2025.03.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2024] [Revised: 03/15/2025] [Accepted: 03/18/2025] [Indexed: 03/23/2025]
Abstract
Cardiovascular disease remains one of the leading causes of mortality in the Western world. Congenital heart disease affects nearly 1 % of newborns, with approximately one-fourth requiring reconstructive surgery during their lifetime. Current cardiovascular replacement options have significant limitations. Their inability to grow poses particular challenges for pediatric patients. Tissue Engineered Matrix (TEM)-based in situ constructs, with their self-repair and growth potential, offer a promising solution to overcome the limitations of current clinically used replacement options. Various functionalization strategies, involving the integration of biomechanical or biochemical components to enhance biocompatibility, have been developed for Tissue Engineered Vascular Grafts (TEVG) and Tissue Engineered Heart Valves (TEHV) to foster their capacity for in vivo remodeling. In this review, we present the current state of clinical translation for TEVG and TEHV, and provide a comprehensive overview of biomechanical and biochemical functionalization strategies for TEVG and TEHV. We discuss the rationale for functionalization, the implementation of functionalization cues in TEM-based TEVG and TEHV, and the interrelatedness of biomechanical and biochemical cues in the in vivo response. Finally, we address the challenges associated with functionalization and discuss how interdisciplinary research, especially when combined with in silico models, could enhance the translation of these strategies into clinical applications. STATEMENT OF SIGNIFICANCE: Cardiovascular disease remains one of the leading causes of mortality, with current replacements being unable to grow and regenerate. In this review, we present the current state of clinical translation for tissue engineered vascular grafts (TEVG) and heart valves (TEHV). Particularly, we discuss the rationale and implementation for functionalization cues in tissue engineered matrix-based TEVGs and TEHVs, and for the first time we introduce the interrelatedness of biomechanical and biochemical cues in the in-vivo response. These insights pave the way for next-generation cardiovascular implants that promise better durability, biocompatibility, and growth potential. Finally, we address the challenges associated with functionalization and discuss how interdisciplinary research, especially when combined with in silico models, could enhance the translation of these strategies into clinical applications .
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Affiliation(s)
- Pascal Breitenstein
- Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren 8952, Switzerland
| | - Valery L Visser
- Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren 8952, Switzerland
| | - Sarah E Motta
- Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren 8952, Switzerland
| | - Marcy Martin
- Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren 8952, Switzerland
| | - Melanie Generali
- Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren 8952, Switzerland
| | - Frank P T Baaijens
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Sandra Loerakker
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Christopher K Breuer
- Center for Regenerative Medicine, Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; Department of Surgery, Nationwide Children's Hospital, Columbus, OH, USA; Department of Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Simon P Hoerstrup
- Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren 8952, Switzerland; Wyss Zurich Translational Center, University of Zurich and ETH Zurich, Zurich 8092, Switzerland
| | - Maximilian Y Emmert
- Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren 8952, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum der Charité (DHZC), Berlin 13353, Germany; Charité Universitätsmedizin Berlin, Berlin 10117, Germany.
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Li Z, Han L, Wang B, Wang P, Wang Y, Wang R, Lv X, Feng Y. The role of Piezo1 in bone marrow stem cells in response to elevated intraosseous pressure on regulating osteogenesis and angiogenesis of steroid-induced osteonecrosis of the femoral head. J Orthop Translat 2025; 51:278-289. [PMID: 40190343 PMCID: PMC11968285 DOI: 10.1016/j.jot.2025.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2024] [Revised: 12/18/2024] [Accepted: 01/08/2025] [Indexed: 04/09/2025] Open
Abstract
Objectives Steroid-induced osteonecrosis of the femoral head (SONFH) remains a significant global health issue, with an unclear pathogenesis. Elevated intraosseous pressure is considered a key initiating factor in SONFH development. Impaired osteogenesis and angiogenesis are believed to be critical in SONFH progression. Piezo1, a mechanosensitive cation channel, may sense changes in intraosseous pressure. In this study, we set out to explore the role of Piezo1 in SONFH and how to target Piezo1 to treat SONFH. Methods Femoral head tissue specimens were collected from patients with ONFH and femoral neck fracture. Histological staining, Western blotting, and RT-PCR analysis were conducted to investigate the relationship between elevated intraosseous pressure and SONFH in rat models. Immunofluorescence staining of femoral head tissues was performed to study the spatiotemporal relationship between elevated intraosseous pressure and angiogenesis, osteogenesis, and development of SONFH. Results In the early stages of SONFH, elevated intraosseous pressure increased angiogenesis and osteogenesis. However, as the pressure continued to rise, both processes were inhibited. Furthermore, Elevated intraosseous pressure activated the Piezo1 signaling pathway in bone marrow stem cells. Piezo1 activation led to increased intracellular calcium influx, thus enhancing osteogenesis and angiogenesis through CAM-NFAT1 signaling pathway. Conclusion In the early stages of SONFH, Piezo1 in BMSCs senses increased intraosseous pressure, promoting angiogenesis and osteogenesis. Targeting Piezo1 to promote the osteogenic and angiogenic potential of stem cells, which could curb further increases in pressure, contribute to early treatment of SONFH. The translational potential of this article Currently, many mechanisms of the impact of elevated intraosseous pressure on osteonecrosis of the femoral head are still in the basic theoretical research stage, and we hope to translate them into clinical applications as soon as possible. We discovered that targeting Piezo1 curb further increases in intraosseous pressure, alleviating the damaging effects of glucocorticoids on stem cells and blood vessels, which exerting great significance in treatment of early stage SONFH.
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Affiliation(s)
- Zilin Li
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lizhi Han
- Department of Orthopedics, The First Affiliated Hospital of Bengbu Medical University, Anhui Key Laboratory of Tissue Transformation, Bengbu Medical University, Bengbu, 233000, Anhui Province, China
| | - Bo Wang
- Department of Rehabilitation, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ping Wang
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuxi Wang
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ruoyu Wang
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao Lv
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yong Feng
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Snyder Y, Jana S. Strategies for Development of Synthetic Heart Valve Tissue Engineering Scaffolds. PROGRESS IN MATERIALS SCIENCE 2023; 139:101173. [PMID: 37981978 PMCID: PMC10655624 DOI: 10.1016/j.pmatsci.2023.101173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
The current clinical solutions, including mechanical and bioprosthetic valves for valvular heart diseases, are plagued by coagulation, calcification, nondurability, and the inability to grow with patients. The tissue engineering approach attempts to resolve these shortcomings by producing heart valve scaffolds that may deliver patients a life-long solution. Heart valve scaffolds serve as a three-dimensional support structure made of biocompatible materials that provide adequate porosity for cell infiltration, and nutrient and waste transport, sponsor cell adhesion, proliferation, and differentiation, and allow for extracellular matrix production that together contributes to the generation of functional neotissue. The foundation of successful heart valve tissue engineering is replicating native heart valve architecture, mechanics, and cellular attributes through appropriate biomaterials and scaffold designs. This article reviews biomaterials, the fabrication of heart valve scaffolds, and their in-vitro and in-vivo evaluations applied for heart valve tissue engineering.
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Affiliation(s)
- Yuriy Snyder
- Department of Bioengineering, University of Missouri, Columbia, MO 65211, USA
| | - Soumen Jana
- Department of Bioengineering, University of Missouri, Columbia, MO 65211, USA
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Karakaya C, van Asten JGM, Ristori T, Sahlgren CM, Loerakker S. Mechano-regulated cell-cell signaling in the context of cardiovascular tissue engineering. Biomech Model Mechanobiol 2022; 21:5-54. [PMID: 34613528 PMCID: PMC8807458 DOI: 10.1007/s10237-021-01521-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/15/2021] [Indexed: 01/18/2023]
Abstract
Cardiovascular tissue engineering (CVTE) aims to create living tissues, with the ability to grow and remodel, as replacements for diseased blood vessels and heart valves. Despite promising results, the (long-term) functionality of these engineered tissues still needs improvement to reach broad clinical application. The functionality of native tissues is ensured by their specific mechanical properties directly arising from tissue organization. We therefore hypothesize that establishing a native-like tissue organization is vital to overcome the limitations of current CVTE approaches. To achieve this aim, a better understanding of the growth and remodeling (G&R) mechanisms of cardiovascular tissues is necessary. Cells are the main mediators of tissue G&R, and their behavior is strongly influenced by both mechanical stimuli and cell-cell signaling. An increasing number of signaling pathways has also been identified as mechanosensitive. As such, they may have a key underlying role in regulating the G&R of tissues in response to mechanical stimuli. A more detailed understanding of mechano-regulated cell-cell signaling may thus be crucial to advance CVTE, as it could inspire new methods to control tissue G&R and improve the organization and functionality of engineered tissues, thereby accelerating clinical translation. In this review, we discuss the organization and biomechanics of native cardiovascular tissues; recent CVTE studies emphasizing the obtained engineered tissue organization; and the interplay between mechanical stimuli, cell behavior, and cell-cell signaling. In addition, we review past contributions of computational models in understanding and predicting mechano-regulated tissue G&R and cell-cell signaling to highlight their potential role in future CVTE strategies.
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Affiliation(s)
- Cansu Karakaya
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Jordy G M van Asten
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Tommaso Ristori
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Cecilia M Sahlgren
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands
- Faculty of Science and Engineering, Biosciences, Åbo Akademi, Turku, Finland
| | - Sandra Loerakker
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, the Netherlands.
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Lou L, Lopez KO, Nautiyal P, Agarwal A. Integrated Perspective of Scaffold Designing and Multiscale Mechanics in Cardiac Bioengineering. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Lihua Lou
- Department of Mechanical and Materials Engineering Florida International University Miami FL 33174 USA
| | - Kazue Orikasa Lopez
- Department of Mechanical and Materials Engineering Florida International University Miami FL 33174 USA
| | - Pranjal Nautiyal
- Mechanical Engineering and Applied Mechanics University of Pennsylvania Philadelphia PA 19104 USA
| | - Arvind Agarwal
- Plasma Forming Laboratory Advanced Materials Engineering Research Institute (AMERI) Mechanical and Materials Engineering College of Engineering and Computing Florida International University Miami FL 33174 USA
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Huang Y, Qian JY, Cheng H, Li XM. Effects of shear stress on differentiation of stem cells into endothelial cells. World J Stem Cells 2021; 13:894-913. [PMID: 34367483 PMCID: PMC8316872 DOI: 10.4252/wjsc.v13.i7.894] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 04/20/2021] [Accepted: 06/22/2021] [Indexed: 02/06/2023] Open
Abstract
Stem cell transplantation is an appealing potential therapy for vascular diseases and an indispensable key step in vascular tissue engineering. Substantial effort has been made to differentiate stem cells toward vascular cell phenotypes, including endothelial cells (ECs) and smooth muscle cells. The microenvironment of vascular cells not only contains biochemical factors that influence differentiation but also exerts hemodynamic forces, such as shear stress and cyclic strain. More recently, studies have shown that shear stress can influence the differentiation of stem cells toward ECs. A deep understanding of the responses and underlying mechanisms involved in this process is essential for clinical translation. This review highlights current data supporting the role of shear stress in stem cell differentiation into ECs. Potential mechanisms and signaling cascades for transducing shear stress into a biological signal are proposed. Further study of stem cell responses to shear stress will be necessary to apply stem cells for pharmacological applications and cardiovascular implants in the realm of regenerative medicine.
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Affiliation(s)
- Yan Huang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
| | - Jia-Yi Qian
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
| | - Hong Cheng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
| | - Xiao-Ming Li
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China.
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8
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Liu H, Usprech JF, Parameshwar PK, Sun Y, Simmons CA. Combinatorial screen of dynamic mechanical stimuli for predictive control of MSC mechano-responsiveness. SCIENCE ADVANCES 2021; 7:7/19/eabe7204. [PMID: 33962940 PMCID: PMC8104874 DOI: 10.1126/sciadv.abe7204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 03/19/2021] [Indexed: 05/05/2023]
Abstract
Mechanobiological-based control of mesenchymal stromal cells (MSCs) to facilitate engineering and regeneration of load-bearing tissues requires systematic investigations of specific dynamic mechanical stimulation protocols. Using deformable membrane microdevice arrays paired with combinatorial experimental design and modeling, we probed the individual and integrative effects of mechanical stimulation parameters (strain magnitude, rate at which strain is changed, and duty period) on myofibrogenesis and matrix production of MSCs in three-dimensional hydrogels. These functions were found to be dominantly influenced by a previously unidentified, higher-order interactive effect between strain magnitude and duty period. Empirical models based on our combinatorial cue-response data predicted an optimal loading regime in which strain magnitude and duty period were increased synchronously over time, which was validated to most effectively promote MSC matrix production. These findings inform the design of loading regimes for MSC-based engineered tissues and validate a broadly applicable approach to probe multifactorial regulating effects of mechanobiological cues.
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Affiliation(s)
- Haijiao Liu
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON M5G 1M1, Canada
| | - Jenna F Usprech
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON M5G 1M1, Canada
| | - Prabu Karthick Parameshwar
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON M5G 1M1, Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada.
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Craig A Simmons
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada.
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON M5G 1M1, Canada
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Gonzalez BA, Perez-Nevarez M, Mirza A, Perez MG, Lin YM, Hsu CPD, Caobi A, Raymond A, Gomez Hernandez ME, Fernandez-Lima F, George F, Ramaswamy S. Physiologically Relevant Fluid-Induced Oscillatory Shear Stress Stimulation of Mesenchymal Stem Cells Enhances the Engineered Valve Matrix Phenotype. Front Cardiovasc Med 2020; 7:69. [PMID: 32509802 PMCID: PMC7248568 DOI: 10.3389/fcvm.2020.00069] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/07/2020] [Indexed: 11/20/2022] Open
Abstract
Support of somatic growth is a fundamental requirement of tissue-engineered valves. However, efforts thus far have been unable to maintain this support long term. A key event that will determine the valve's long-term success is the extent to which healthy host tissue remodeling can occur on the valve soon after implantation. The construct's phenotypic-status plays a critical role in accelerating tissue remodeling and engineered valve integration with the host via chemotaxis. In the current study, human bone-marrow-derived mesenchymal stem cells were utilized to seed synthetic, biodegradable scaffolds for a period of 8 days in rotisserie culture. Subsequently, cell-seeded scaffolds were exposed to physiologically relevant oscillatory shear stresses (overall mean, time-averaged shear stress, ~7.9 dynes/cm2; overall mean, oscillatory shear index, ~0.18) for an additional 2 weeks. The constructs were found to exhibit relatively augmented endothelial cell expression (CD31; compared to static controls) but concomitantly served to restrict the level of the activated smooth muscle phenotype (α-SMA) and also produced very low stem cell secretion levels of fibronectin (p < 0.05 compared to static and rotisserie controls). These findings suggest that fluid-induced oscillatory shear stresses alone are important in regulating a healthy valve phenotype of the engineered tissue matrix. Moreover, as solid stresses could lead to increased α-SMA levels, they should be excluded from conditioning during the culture process owing to their associated potential risks with pathological tissue remodeling. In conclusion, engineered valve tissues derived from mesenchymal stem cells revealed both a relatively robust valvular phenotype after exposure to physiologically relevant scales of oscillatory shear stress and may thereby serve to accelerate healthy valve tissue remodeling in the host post-implantation.
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Affiliation(s)
- Brittany A Gonzalez
- Cardiovascular Therapeutics Laboratory (CV-PEUTICS Lab), Department of Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Manuel Perez-Nevarez
- Cardiovascular Therapeutics Laboratory (CV-PEUTICS Lab), Department of Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Asad Mirza
- Cardiovascular Therapeutics Laboratory (CV-PEUTICS Lab), Department of Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Marcos Gonzalez Perez
- Cardiovascular Therapeutics Laboratory (CV-PEUTICS Lab), Department of Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Yih-Mei Lin
- Cardiovascular Therapeutics Laboratory (CV-PEUTICS Lab), Department of Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Chia-Pei Denise Hsu
- Cardiovascular Therapeutics Laboratory (CV-PEUTICS Lab), Department of Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Allen Caobi
- Department of Immunology and Nano-Medicine, Florida International University, Miami, FL, United States
| | - Andrea Raymond
- Department of Immunology and Nano-Medicine, Florida International University, Miami, FL, United States
| | - Mario E Gomez Hernandez
- Advanced Mass Spectrometry Facility, Florida International University, Miami, FL, United States.,Department of Chemistry and Biochemistry, Florida International University, Miami, FL, United States
| | - Francisco Fernandez-Lima
- Advanced Mass Spectrometry Facility, Florida International University, Miami, FL, United States.,Department of Chemistry and Biochemistry, Florida International University, Miami, FL, United States
| | - Florence George
- Department of Mathematics and Statistics, Florida International University, Miami, FL, United States
| | - Sharan Ramaswamy
- Cardiovascular Therapeutics Laboratory (CV-PEUTICS Lab), Department of Biomedical Engineering, Florida International University, Miami, FL, United States
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Chester AH, Grande-Allen KJ. Which Biological Properties of Heart Valves Are Relevant to Tissue Engineering? Front Cardiovasc Med 2020; 7:63. [PMID: 32373630 PMCID: PMC7186395 DOI: 10.3389/fcvm.2020.00063] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 03/27/2020] [Indexed: 12/30/2022] Open
Abstract
Over the last 20 years, the designs of tissue engineered heart valves have evolved considerably. An initial focus on replicating the mechanical and structural features of semilunar valves has expanded to endeavors to mimic the biological behavior of heart valve cells as well. Studies on the biology of heart valves have shown that the function and durability of native valves is underpinned by complex interactions between the valve cells, the extracellular matrix, and the mechanical environment in which heart valves function. The ability of valve interstitial cells to synthesize extracellular matrix proteins and remodeling enzymes and the protective mediators released by endothelial cells are key factors in the homeostasis of valve function. The extracellular matrix provides the mechanical strength and flexibility required for the valve to function, as well as communicating with the cells that are bound within. There are a number of regulatory mechanisms that influence valve function, which include neuronal mechanisms and the tight regulation of growth and angiogenic factors. Together, studies into valve biology have provided a blueprint for what a tissue engineered valve would need to be capable of, in order to truly match the function of the native valve. This review addresses the biological functions of heart valve cells, in addition to the influence of the cells' environment on this behavior and examines how well these functions are addressed within the current strategies for tissue engineering heart valves in vitro, in vivo, and in situ.
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Affiliation(s)
- Adrian H Chester
- Heart Science Centre, The Magdi Yacoub Institute, Harefield, United Kingdom
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11
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Elastin-Dependent Aortic Heart Valve Leaflet Curvature Changes During Cyclic Flexure. Bioengineering (Basel) 2019; 6:bioengineering6020039. [PMID: 31067726 PMCID: PMC6631801 DOI: 10.3390/bioengineering6020039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 05/03/2019] [Accepted: 05/05/2019] [Indexed: 12/20/2022] Open
Abstract
The progression of calcific aortic valve disease (CAVD) is characterized by extracellular matrix (ECM) remodeling, leading to structural abnormalities and improper valve function. The focus of the present study was to relate aortic valve leaflet axial curvature changes as a function of elastin degradation, which has been associated with CAVD. Circumferential rectangular strips (L × W = 10 × 2.5 mm) of normal and elastin-degraded (via enzymatic digestion) porcine AV leaflets were subjected to cyclic flexure (1 Hz). A significant increase in mean curvature (p < 0.05) was found in elastin-degraded leaflet specimens in comparison to un-degraded controls at both the semi-constrained (50% of maximum flexed state during specimen bending and straightening events) and fully-constrained (maximally-flexed) states. This significance did not occur in all three flexed configurations when measurements were performed using either minimum or maximum curvature. Moreover, the mean curvature increase in the elastin-degraded leaflets was most pronounced at the instance of maximum flexure, compared to un-degraded controls. We conclude that the mean axial curvature metric can detect distinct spatial changes in aortic valve ECM arising from the loss in bulk content and/or structure of elastin, particularly when there is a high degree of tissue bending. Therefore, the instance of maximum leaflet flexure during the cardiac cycle could be targeted for mean curvature measurements and serve as a potential biomarker for elastin degradation in early CAVD remodeling.
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12
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van Haaften EE, Wissing TB, Rutten MCM, Bulsink JA, Gashi K, van Kelle MAJ, Smits AIPM, Bouten CVC, Kurniawan NA. Decoupling the Effect of Shear Stress and Stretch on Tissue Growth and Remodeling in a Vascular Graft. Tissue Eng Part C Methods 2019; 24:418-429. [PMID: 29877143 DOI: 10.1089/ten.tec.2018.0104] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The success of cardiovascular tissue engineering (TE) strategies largely depends on the mechanical environment in which cells develop a neotissue through growth and remodeling processes. This mechanical environment is defined by the local scaffold architecture to which cells adhere, that is, the microenvironment, and by external mechanical cues to which cells respond, that is, hemodynamic loading. The hemodynamic environment of early developing blood vessels consists of both shear stress (due to blood flow) and circumferential stretch (due to blood pressure). Experimental platforms that recapitulate this mechanical environment in a controlled and tunable manner are thus critical for investigating cardiovascular TE. In traditional perfusion bioreactors, however, shear stress and stretch are coupled, hampering a clear delineation of their effects on cell and tissue response. In this study, we uniquely designed a bioreactor that independently combines these two types of mechanical cues in eight parallel vascular grafts. The system is computationally and experimentally validated, through finite element analysis and culture of tissue constructs, respectively, to distinguish various levels of shear stress (up to 5 Pa) and cyclic stretch (up to 1.10). To illustrate the usefulness of the system, we investigated the relative contribution of cyclic stretch (1.05 at 0.5 Hz) and shear stress (1 Pa) to tissue development. Both types of hemodynamic loading contributed to cell alignment, but the contribution of shear stress overruled stretch-induced cell proliferation and matrix (i.e., collagen and glycosaminoglycan) production. At a macroscopic level, cyclic stretching led to the most linear stress-stretch response, which was not related to the presence of shear stress. In conclusion, we have developed a bioreactor that is particularly suited to further unravel the interplay between hemodynamics and in situ TE processes. Using the new system, this work highlights the importance of hemodynamic loading to the study of developing vascular tissues.
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Affiliation(s)
- Eline E van Haaften
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands .,2 Institute for Complex Molecular Systems, Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Tamar B Wissing
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands .,2 Institute for Complex Molecular Systems, Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Marcel C M Rutten
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Jurgen A Bulsink
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Kujtim Gashi
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Mathieu A J van Kelle
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands .,2 Institute for Complex Molecular Systems, Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Anthal I P M Smits
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands .,2 Institute for Complex Molecular Systems, Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Carlijn V C Bouten
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands .,2 Institute for Complex Molecular Systems, Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Nicholas A Kurniawan
- 1 Department of Biomedical Engineering, Eindhoven University of Technology , Eindhoven, The Netherlands .,2 Institute for Complex Molecular Systems, Eindhoven University of Technology , Eindhoven, The Netherlands
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13
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Jover E, Fagnano M, Angelini G, Madeddu P. Cell Sources for Tissue Engineering Strategies to Treat Calcific Valve Disease. Front Cardiovasc Med 2018; 5:155. [PMID: 30460245 PMCID: PMC6232262 DOI: 10.3389/fcvm.2018.00155] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 10/10/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiovascular calcification is an independent risk factor and an established predictor of adverse cardiovascular events. Despite concomitant factors leading to atherosclerosis and heart valve disease (VHD), the latter has been identified as an independent pathological entity. Calcific aortic valve stenosis is the most common form of VDH resulting of either congenital malformations or senile “degeneration.” About 2% of the population over 65 years is affected by aortic valve stenosis which represents a major cause of morbidity and mortality in the elderly. A multifactorial, complex and active heterotopic bone-like formation process, including extracellular matrix remodeling, osteogenesis and angiogenesis, drives heart valve “degeneration” and calcification, finally causing left ventricle outflow obstruction. Surgical heart valve replacement is the current therapeutic option for those patients diagnosed with severe VHD representing more than 20% of all cardiac surgeries nowadays. Tissue Engineering of Heart Valves (TEHV) is emerging as a valuable alternative for definitive treatment of VHD and promises to overcome either the chronic oral anticoagulation or the time-dependent deterioration and reintervention of current mechanical or biological prosthesis, respectively. Among the plethora of approaches and stablished techniques for TEHV, utilization of different cell sources may confer of additional properties, desirable and not, which need to be considered before moving from the bench to the bedside. This review aims to provide a critical appraisal of current knowledge about calcific VHD and to discuss the pros and cons of the main cell sources tested in studies addressing in vitro TEHV.
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Affiliation(s)
- Eva Jover
- Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
| | - Marco Fagnano
- Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
| | - Gianni Angelini
- Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
| | - Paolo Madeddu
- Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
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14
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D'Amore A, Nasello G, Luketich SK, Denisenko D, Jacobs DL, Hoff R, Gibson G, Bruno A, T Raimondi M, Wagner WR. Meso-scale topological cues influence extracellular matrix production in a large deformation, elastomeric scaffold model. SOFT MATTER 2018; 14:8483-8495. [PMID: 30357253 DOI: 10.1039/c8sm01352g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Physical cues are decisive factors in extracellular matrix (ECM) formation and elaboration. Their transduction across scale lengths is an inherently symbiotic phenomenon that while influencing ECM fate is also mediated by the ECM structure itself. This study investigates the possibility of enhancing ECM elaboration by topological cues that, while not modifying the substrate macro scale mechanics, can affect the meso-scale strain range acting on cells incorporated within the scaffold. Vascular smooth muscle cell micro-integrated, electrospun scaffolds were fabricated with comparable macroscopic biaxial mechanical response, but different meso-scale topology. Seeded scaffolds were conditioned on a stretch bioreactor and exposed to large strain deformations. Samples were processed to evaluate ECM quantity and quality via: biochemical assay, qualitative and quantitative histological assessment and multi-photon analysis. Experimental evaluation was coupled to a numerical model that elucidated the relationship between the scaffold micro-architecture and the strain acting on the cells. Results showed an higher amount of ECM formation for the scaffold type characterized by lowest fiber intersection density. The numerical model simulations associated this result with the differences found for the change in cell nuclear aspect ratio and showed that given comparable macro scale mechanics, a difference in material topology created significant differences in cell-scaffold meso-scale deformations. These findings reaffirmed the role of cell shape in ECM formation and introduced a novel notion for the engineering of cardiac tissue where biomaterial structure can be designed to both mimick the organ level mechanics of a specific tissue of interest and elicit a desirable cellular response.
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Affiliation(s)
- Antonio D'Amore
- Departments of Bioengineering and Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Pittsburgh, 15216, USA.
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15
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Quantitative Characterization of Aortic Valve Endothelial Cell Viability and Morphology In Situ Under Cyclic Stretch. Cardiovasc Eng Technol 2018; 10:173-180. [PMID: 30141125 DOI: 10.1007/s13239-018-00375-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 08/17/2018] [Indexed: 10/28/2022]
Abstract
Current protocols for mechanical preconditioning of tissue engineered heart valves have focused on application of pressure, flexure and fluid flow to stimulate collagen production, ECM remodeling and improving mechanical performance. The aim of this study was to determine if mechanical preconditioning with cyclic stretch could promote an intact endothelium that resembled the viability and morphology of a native valve. Confocal laser scanning microscopy was used to image endothelial cells on aortic valve strips subjected to static incubation or physiological strain regimens. An automated image analysis program was designed and implemented to detect and analyze live and dead cells in images captured of a live aortic valve endothelium. The images were preprocessed, segmented, and quantitatively analyzed for live/dead cell ratio, minimum neighbor distance and circularity. Significant differences in live/dead cellular ratio and the minimum distance between cells were observed between static and strained endothelia, indicating that cyclic strain is an important stimulus for maintaining a healthy endothelium. In conclusion, in vitro application of physiological levels of cyclic strain to tissue engineered heart valves seeded with autologous endothelial cells would be advantageous.
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16
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Castellanos G, Nasim S, Almora DM, Rath S, Ramaswamy S. Stem Cell Cytoskeletal Responses to Pulsatile Flow in Heart Valve Tissue Engineering Studies. Front Cardiovasc Med 2018; 5:58. [PMID: 29922678 PMCID: PMC5996090 DOI: 10.3389/fcvm.2018.00058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 05/15/2018] [Indexed: 01/12/2023] Open
Abstract
Heart valve replacement options remain exceedingly limited for pediatric patients because they cannot accommodate somatic growth. To overcome this shortcoming, heart valve tissue engineering using human bone marrow stem cells (HBMSCs) has been considered a potential solution to the treatment of critical congenital valvular defects. The mechanical environments during in vitro culture are key regulators of progenitor cell fate. Here, we report on alterations in HBMSCs, specifically in their actin cytoskeleton and their nucleus under fluid-induced shear stresses of relevance to heart valves. HBMSCs were seeded in microfluidic channels and were exposed to the following conditions: pulsatile shear stress (PSS), steady shear stress (SS), and no flow controls (n = 4/group). Changes to the actin filament structure were monitored and subsequent gene expression was evaluated. A significant increase (p < 0.05) in the number of actin filaments, filament density and angle (between 30° and 84°), and conversely a significant decrease (p < 0.05) in the length of the filaments were observed when the HBMSCs were exposed to PSS for 48 h compared to SS and no flow conditions. No significant differences in nuclear shape were observed among the groups (p > 0.05). Of particular relevance to valvulogenesis, klf2a, a critical gene in valve development, was significantly expressed only by the PSS group (p < 0.05). We conclude that HBMSCs respond to PSS by alterations to their actin filament structure that are distinct from SS and no flow conditions. These changes coupled with the subsequent gene expression findings suggest that at the cellular level, the immediate effect of PSS is to initiate a unique set of quantifiable cytoskeletal events (increased actin filament number, density and angle, but decrease in filament length) in stem cells, which could be useful in the fine-tuning of in vitro protocols in heart valve tissue engineering.
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Affiliation(s)
- Glenda Castellanos
- Tissue Engineered Mechanics Imaging and Materials Laboratory, Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Sana Nasim
- Tissue Engineered Mechanics Imaging and Materials Laboratory, Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Denise M Almora
- Tissue Engineered Mechanics Imaging and Materials Laboratory, Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Sasmita Rath
- Tissue Engineered Mechanics Imaging and Materials Laboratory, Biomedical Engineering, Florida International University, Miami, FL, United States
| | - Sharan Ramaswamy
- Tissue Engineered Mechanics Imaging and Materials Laboratory, Biomedical Engineering, Florida International University, Miami, FL, United States
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17
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Mesenchymal Stromal Cells: From Discovery to Manufacturing and Commercialization. Stem Cells Int 2018; 2018:4083921. [PMID: 30057622 PMCID: PMC6051015 DOI: 10.1155/2018/4083921] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/01/2018] [Accepted: 03/11/2018] [Indexed: 02/07/2023] Open
Abstract
Over the last decades, mesenchymal stromal cells (MSC) have been the focus of intense research by academia and industry due to their unique features. MSC can be easily isolated and expanded through in vitro culture by taking full advantage of their self-renewing capacity. In addition, MSC exert immunomodulatory effects and can be differentiated into various lineages, which makes them highly attractive for clinical applications in cell-based therapies. In this review, we attempt to provide a brief historical overview of MSC discovery, characterization, and the first clinical studies conducted. The current MSC manufacturing platforms are reviewed with special attention regarding the use of bioreactors for the production of GMP-compliant clinically relevant cell numbers. The first commercial MSC-based products are also addressed, as well as the remaining challenges to the widespread use of MSC-derived products.
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18
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Cell Colonization Ability of a Commercialized Large Porous Alveolar Scaffold. Appl Bionics Biomech 2018; 2017:8949264. [PMID: 29386882 PMCID: PMC5745715 DOI: 10.1155/2017/8949264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 09/22/2017] [Accepted: 09/27/2017] [Indexed: 11/17/2022] Open
Abstract
The use of filling biomaterials or tissue-engineered large bone implant-coupling biocompatible materials and human bone marrow mesenchymal stromal cells seems to be a promising approach to treat critical-sized bone defects. However, the cellular seeding onto and into large porous scaffolds still remains challenging since this process highly depends on the porous microstructure. Indeed, the cells may mainly colonize the periphery of the scaffold, leaving its volume almost free of cells. In this study, we carry out an in vitro study to analyze the ability of a commercialized scaffold to be in vivo colonized by cells. We investigate the influence of various physical parameters on the seeding efficiency of a perfusion seeding protocol using large manufactured bone substitutes. The present study shows that the velocity of the perfusion fluid and the initial cell density seem to impact the seeding results and to have a negative effect on the cellular viability, whereas the duration of the fluid perfusion and the nature of the flow (steady versus pulsed) did not show any influence on either the fraction of seeded cells or the cellular viability rate. However, the cellular repartition after seeding remains highly heterogeneous.
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19
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Ravichandran A, Wen F, Lim J, Chong MSK, Chan JK, Teoh S. Biomimetic fetal rotation bioreactor for engineering bone tissues—Effect of cyclic strains on upregulation of osteogenic gene expression. J Tissue Eng Regen Med 2018; 12:e2039-e2050. [DOI: 10.1002/term.2635] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 11/28/2017] [Accepted: 12/11/2017] [Indexed: 12/28/2022]
Affiliation(s)
| | - Feng Wen
- School of Chemical and Biomedical EngineeringNanyang Technological University Singapore
| | - Jing Lim
- School of Chemical and Biomedical EngineeringNanyang Technological University Singapore
| | - Mark Seow Khoon Chong
- School of Chemical and Biomedical EngineeringNanyang Technological University Singapore
| | - Jerry K.Y. Chan
- Department of Reproductive MedicineKK Women's and Children's Hospital Singapore
- Cancer and Stem Cell Biology ProgramDuke‐NUS Graduate Medical School Singapore
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of MedicineNational University of Singapore Singapore
| | - Swee‐Hin Teoh
- School of Chemical and Biomedical EngineeringNanyang Technological University Singapore
- Lee Kong Chian School of Medicine, Experimental Medicine BuildingNanyang Technological University Singapore
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20
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Williams A, Nasim S, Salinas M, Moshkforoush A, Tsoukias N, Ramaswamy S. A "sweet-spot" for fluid-induced oscillations in the conditioning of stem cell-based engineered heart valve tissues. J Biomech 2017; 65:40-48. [PMID: 29054608 DOI: 10.1016/j.jbiomech.2017.09.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 12/21/2022]
Abstract
Fluid-induced shear stresses are involved in the development of cardiovascular tissues. In a tissue engineering framework, this stimulus has also been considered as a mechanical regulator of stem cell differentiation. We recently demonstrated that the fluid-oscillating effect in combination with a physiologically-relevant shear stress magnitude contributes to the formation of stem cell-derived de novo heart valve tissues. However, the range of oscillations necessary to induce favorable gene expression and engineered tissue formation is unknown. In this study, we took a computational approach to establish a range of oscillatory shear stresses that may optimize in vitro valvular tissue growth. Taking a biomimetic approach, three physiologically-relevant flow waveforms from the human: (i) aorta, (ii) pulmonary artery and (iii) superior vena cava were utilized to simulate pulsatile flow conditions within a bioreactor that housed 3 tissue specimens. Results were compared to non-physiological pulsatile flow (NPPF) and cyclic flexure-steady flow (Flex-Flow) conditions. The oscillatory shear index (OSI) was used to quantify the fluid-induced oscillations occurring on the specimen surfaces. The range of mean OSI under the physiological conditions investigated was found to be 0.18 ≤ OSI ≤ 0.23. On the other hand, NPPF and Flex-Flow environments yielded a mean OSI of 0.37 and 0.11 respectively, which were 46% higher and 45% lower than physiological conditions. Moreover, we subsequently conducted OSI-based human bone marrow stem cell (HBMSC) culture experiments which resulted in preferential valvular gene expression and phenotype (significant upregulation of BMP, KLF2A, CD31 and α-SMA using an OSI of 0.23 in comparison to a lower OSI of 0.10 or a higher OSI of 0.38; p < .05). These findings suggest that a distinct range or a "sweet-spot" for physiological OSI exists in the mechanical conditioning of tissue engineered heart valves grown from stem cell sources. We conclude that in vitro heart valve matrix development could be further enhanced by simultaneous exposure of the engineered tissues to physiologically-relevant magnitudes of both fluid-induced oscillations and shear stresses.
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Affiliation(s)
- Alexander Williams
- Department of Biomedical Engineering, Florida International University, 10555 W Flagler St., Miami, FL 33174, United States
| | - Sana Nasim
- Department of Biomedical Engineering, Florida International University, 10555 W Flagler St., Miami, FL 33174, United States
| | - Manuel Salinas
- College of Engineering, Nova Southeastern University, 3301 College Ave, Fort Lauderdale, FL 33314, United States
| | - Arash Moshkforoush
- Department of Biomedical Engineering, Florida International University, 10555 W Flagler St., Miami, FL 33174, United States
| | - Nikolaos Tsoukias
- Department of Biomedical Engineering, Florida International University, 10555 W Flagler St., Miami, FL 33174, United States
| | - Sharan Ramaswamy
- Department of Biomedical Engineering, Florida International University, 10555 W Flagler St., Miami, FL 33174, United States.
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21
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Namdari M, Negahdari B, Eatemadi A. Paediatric nanofibrous bioprosthetic heart valve. IET Nanobiotechnol 2017; 11:493-500. [PMID: 28745279 PMCID: PMC8676244 DOI: 10.1049/iet-nbt.2016.0159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/28/2016] [Accepted: 11/30/2016] [Indexed: 09/22/2023] Open
Abstract
The search for an optimal aortic valve implant with durability, calcification resistance, excellent haemodynamic parameters and ability to withstand mechanical loading is yet to be met. Thus, there has been struggled to fabricate bio-prosthetics heart valve using bioengineering. The consequential product must be resilient with suitable mechanical features, biocompatible and possess the capacity to grow. Defective heart valves replacement by surgery is now common, this improves the value and survival of life for a lot of patients. The recent paediatric heart valve implant is suboptimal due to their inability of somatic growth. They usually have multiple surgeries to change outgrown valves. Short-lived valve bio-prostheses occurring in older patients and younger ones who more usually need the replacement of its damaged heart with prosthesis led to a new invasive surgical interventions with an improved quality of life. The authors propose that nanofibre scaffold for paediatric tissue-engineered heart valve will meet most of these conditions, most particularly those related to somatic growth, and, as the nanofibre scaffold is eroded, new valve is produced, the valve matures in the child until adulthood.
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Affiliation(s)
- Mehrdad Namdari
- Department of Cardiology, Lorestan University of Medical Sciences, Khoramabad, Iran
| | - Babak Negahdari
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Eatemadi
- Department of Medical Biotechnology, School of Medicine, Lorestan University of Medical Sciences, Lorestan, Iran.
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22
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Xue Y, Sant V, Phillippi J, Sant S. Biodegradable and biomimetic elastomeric scaffolds for tissue-engineered heart valves. Acta Biomater 2017; 48:2-19. [PMID: 27780764 DOI: 10.1016/j.actbio.2016.10.032] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 10/13/2016] [Accepted: 10/22/2016] [Indexed: 01/04/2023]
Abstract
Valvular heart diseases are the third leading cause of cardiovascular disease, resulting in more than 25,000 deaths annually in the United States. Heart valve tissue engineering (HVTE) has emerged as a putative treatment strategy such that the designed construct would ideally withstand native dynamic mechanical environment, guide regeneration of the diseased tissue and more importantly, have the ability to grow with the patient. These desired functions could be achieved by biomimetic design of tissue-engineered constructs that recapitulate in vivo heart valve microenvironment with biomimetic architecture, optimal mechanical properties and possess suitable biodegradability and biocompatibility. Synthetic biodegradable elastomers have gained interest in HVTE due to their excellent mechanical compliance, controllable chemical structure and tunable degradability. This review focuses on the state-of-art strategies to engineer biomimetic elastomeric scaffolds for HVTE. We first discuss the various types of biodegradable synthetic elastomers and their key properties. We then highlight tissue engineering approaches to recreate some of the features in the heart valve microenvironment such as anisotropic and hierarchical tri-layered architecture, mechanical anisotropy and biocompatibility. STATEMENT OF SIGNIFICANCE Heart valve tissue engineering (HVTE) is of special significance to overcome the drawbacks of current valve replacements. Although biodegradable synthetic elastomers have emerged as promising materials for HVTE, a mature HVTE construct made from synthetic elastomers for clinical use remains to be developed. Hence, this review summarized various types of biodegradable synthetic elastomers and their key properties. The major focus that distinguishes this review from the current literature is the thorough discussion on the key features of native valve microenvironments and various up-and-coming approaches to engineer synthetic elastomers to recreate these features such as anisotropic tri-layered architecture, mechanical anisotropy, biodegradability and biocompatibility. This review is envisioned to inspire and instruct the design of functional HVTE constructs and facilitate their clinical translation.
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23
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Namdari M, Eatemadi A. Nanofibrous bioengineered heart valve—Application in paediatric medicine. Biomed Pharmacother 2016; 84:1179-1188. [DOI: 10.1016/j.biopha.2016.10.058] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 10/17/2016] [Accepted: 10/17/2016] [Indexed: 12/22/2022] Open
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24
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Huang S, Huang HYS. Biaxial stress relaxation of semilunar heart valve leaflets during simulated collagen catabolism: Effects of collagenase concentration and equibiaxial strain state. Proc Inst Mech Eng H 2016; 229:721-31. [PMID: 26405097 DOI: 10.1177/0954411915604336] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Heart valve leaflet collagen turnover and remodeling are innate to physiological homeostasis; valvular interstitial cells routinely catabolize damaged collagen and affect repair. Moreover, evidence indicates that leaflets can adapt to altered physiological (e.g. pregnancy) and pathological (e.g. hypertension) mechanical load states, tuning collagen structure and composition to changes in pressure and flow. However, while valvular interstitial cell-secreted matrix metalloproteinases are considered the primary effectors of collagen catabolism, the mechanisms by which damaged collagen fibers are selectively degraded remain unclear. Growing evidence suggests that the collagen fiber strain state plays a key role, with the strain-dependent configuration of the collagen molecules either masking or presenting proteolytic sites, thereby protecting or accelerating collagen proteolysis. In this study, the effects of equibiaxial strain state on collagen catabolism were investigated in porcine aortic valve and pulmonary valve tissues. Bacterial collagenase (0.2 and 0.5 mg/mL) was utilized to simulate endogenous matrix metalloproteinases, and biaxial stress relaxation and biochemical collagen concentration served as functional and compositional measures of collagen catabolism, respectively. At a collagenase concentration of 0.5 mg/mL, increasing the equibiaxial strain imposed during stress relaxation (0%, 37.5%, and 50%) yielded significantly lower median collagen concentrations in the aortic valve (p = 0.0231) and pulmonary valve (p = 0.0183), suggesting that relatively large strain magnitudes may enhance collagen catabolism. Collagen concentration decreases were paralleled by trends of accelerated normalized stress relaxation rate with equibiaxial strain in aortic valve tissues. Collectively, these in vitro results indicate that biaxial strain state is capable of affecting the susceptibility of valvular collagens to catabolism, providing a basis for further investigation of how such phenomena may manifest at different strain magnitudes or in vivo.
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Affiliation(s)
- Siyao Huang
- Department of Mechanical & Aerospace Engineering, North Carolina State University, Raleigh, NC, USA
| | - Hsiao-Ying Shadow Huang
- Department of Mechanical & Aerospace Engineering, North Carolina State University, Raleigh, NC, USA
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25
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D'Amore A, Soares JS, Stella JA, Zhang W, Amoroso NJ, Mayer JE, Wagner WR, Sacks MS. Large strain stimulation promotes extracellular matrix production and stiffness in an elastomeric scaffold model. J Mech Behav Biomed Mater 2016; 62:619-635. [PMID: 27344402 PMCID: PMC4955736 DOI: 10.1016/j.jmbbm.2016.05.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 04/30/2016] [Accepted: 05/03/2016] [Indexed: 01/07/2023]
Abstract
Mechanical conditioning of engineered tissue constructs is widely recognized as one of the most relevant methods to enhance tissue accretion and microstructure, leading to improved mechanical behaviors. The understanding of the underlying mechanisms remains rather limited, restricting the development of in silico models of these phenomena, and the translation of engineered tissues into clinical application. In the present study, we examined the role of large strip-biaxial strains (up to 50%) on ECM synthesis by vascular smooth muscle cells (VSMCs) micro-integrated into electrospun polyester urethane urea (PEUU) constructs over the course of 3 weeks. Experimental results indicated that VSMC biosynthetic behavior was quite sensitive to tissue strain maximum level, and that collagen was the primary ECM component synthesized. Moreover, we found that while a 30% peak strain level achieved maximum ECM synthesis rate, further increases in strain level lead to a reduction in ECM biosynthesis. Subsequent mechanical analysis of the formed collagen fiber network was performed by removing the scaffold mechanical responses using a strain-energy based approach, showing that the denovo collagen also demonstrated mechanical behaviors substantially better than previously obtained with small strain training and comparable to mature collagenous tissues. We conclude that the application of large deformations can play a critical role not only in the quantity of ECM synthesis (i.e. the rate of mass production), but also on the modulation of the stiffness of the newly formed ECM constituents. The improved understanding of the process of growth and development of ECM in these mechano-sensitive cell-scaffold systems will lead to more rational design and manufacturing of engineered tissues operating under highly demanding mechanical environments.
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Affiliation(s)
- Antonio D'Amore
- Department of Bioengineering McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Fondazione RiMED, Italy; DICGIM, Università di Palermo, Italy
| | - Joao S Soares
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - John A Stella
- Department of Bioengineering McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Will Zhang
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Nicholas J Amoroso
- Department of Bioengineering McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - John E Mayer
- Department of Cardiac Surgery Boston Children׳s Hospital and Harvard Medical School, Boston, MA, USA
| | - William R Wagner
- Department of Bioengineering McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael S Sacks
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.
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26
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Pressure and wall shear stress in blood hammer - Analytical theory. Math Biosci 2016; 280:62-70. [PMID: 27474207 DOI: 10.1016/j.mbs.2016.07.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 07/14/2016] [Accepted: 07/20/2016] [Indexed: 11/23/2022]
Abstract
We describe an analytical theory of blood hammer in a long and stiffened artery due to sudden blockage. Based on the model of a viscous fluid in laminar flow, we derive explicit expressions of oscillatory pressure and wall shear stress. To examine the effects on local plaque formation we also allow the blood vessel radius to be slightly nonuniform. Without resorting to discrete computation, the asymptotic method of multiple scales is utilized to deal with the sharp contrast of time scales. The effects of plaque and blocking time on blood pressure and wall shear stress are studied. The theory is validated by comparison with existing water hammer experiments.
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27
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Zhao L, Fan C, Zhang Y, Yang Y, Wang D, Deng C, Hu W, Ma Z, Jiang S, Di S, Qin Z, Lv J, Sun Y, Yi W. Adiponectin enhances bone marrow mesenchymal stem cell resistance to flow shear stress through AMP-activated protein kinase signaling. Sci Rep 2016; 6:28752. [PMID: 27418435 PMCID: PMC4945870 DOI: 10.1038/srep28752] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 06/08/2016] [Indexed: 12/17/2022] Open
Abstract
Adiponectin has been demonstrated to protect the cardiovascular system and bone marrow mesenchymal stem cells (BMSCs). However, it is unclear whether adiponectin can protect BMSCs against flow shear stress (FSS). In this study, our aim was to explore the effects of adiponectin on BMSCs and to explore the role of AMP-activated protein kinase (AMPK) signaling in this process. Shear stress significantly inhibits the survival and increases the apoptosis of BMSCs in an intensity-dependent manner. The expression levels of TGF-β, bFGF, VEGF, PDGF, and Bcl2 are simultaneously reduced, and the phosphorylation levels of AMPK and ACC, as well as the expression level of Bax, are increased. Supplementation with adiponectin promotes the survival of BMSCs; reverses the changes in the expression levels of TGF-β, bFGF, VEGF, PDGF, Bcl2, and Bax; and further amplifies the phosphorylation of AMPK and ACC. Furthermore, the protective effects of adiponectin can be partially neutralized by AMPK siRNA. In summary, we have demonstrated for the first time that adiponectin can effectively protect BMSCs from FSS and that this effect depends, at least in part, on the activation of AMPK signaling.
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Affiliation(s)
- Lin Zhao
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China.,Department of Geriatrics, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China
| | - Chongxi Fan
- Department of Thoracic Surgery, Tangdu Hospital, The Fourth Military Medical University, 1 Xinsi Road, Xi'an 710038, China
| | - Yu Zhang
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China
| | - Yang Yang
- Department of Thoracic and Cardiovascular Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, Jiangsu, China.,Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Dongjin Wang
- Department of Thoracic and Cardiovascular Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Chao Deng
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China
| | - Wei Hu
- Department of Thoracic and Cardiovascular Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Zhiqiang Ma
- Department of Thoracic Surgery, Tangdu Hospital, The Fourth Military Medical University, 1 Xinsi Road, Xi'an 710038, China
| | - Shuai Jiang
- Department of Aerospace Medicine, The Fourth Military Medical University, Xi'an 710032, China
| | - Shouyi Di
- Department of Thoracic Surgery, Tangdu Hospital, The Fourth Military Medical University, 1 Xinsi Road, Xi'an 710038, China
| | - Zhigang Qin
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China
| | - Jianjun Lv
- Department of Thoracic and Cardiovascular Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Yang Sun
- Department of Geriatrics, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China
| | - Wei Yi
- Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China
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28
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Chang CW, Petrie T, Clark A, Lin X, Sondergaard CS, Griffiths LG. Mesenchymal Stem Cell Seeding of Porcine Small Intestinal Submucosal Extracellular Matrix for Cardiovascular Applications. PLoS One 2016; 11:e0153412. [PMID: 27070546 PMCID: PMC4829265 DOI: 10.1371/journal.pone.0153412] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 03/29/2016] [Indexed: 01/16/2023] Open
Abstract
In this study, we investigate the translational potential of a novel combined construct using an FDA-approved decellularized porcine small intestinal submucosa extracellular matrix (SIS-ECM) seeded with human or porcine mesenchymal stem cells (MSCs) for cardiovascular indications. With the emerging success of individual component in various clinical applications, the combination of SIS-ECM with MSCs could provide additional therapeutic potential compared to individual components alone for cardiovascular repair. We tested the in vitro effects of MSC-seeding on SIS-ECM on resultant construct structure/function properties and MSC phenotypes. Additionally, we evaluated the ability of porcine MSCs to modulate recipient graft-specific response towards SIS-ECM in a porcine cardiac patch in vivo model. Specifically, we determined: 1) in vitro loading-capacity of human MSCs on SIS-ECM, 2) effect of cell seeding on SIS-ECM structure, compositions and mechanical properties, 3) effect of SIS-ECM seeding on human MSC phenotypes and differentiation potential, and 4) optimal orientation and dose of porcine MSCs seeded SIS-ECM for an in vivo cardiac application. In this study, histological structure, biochemical compositions and mechanical properties of the FDA-approved SIS-ECM biomaterial were retained following MSCs repopulation in vitro. Similarly, the cellular phenotypes and differentiation potential of MSCs were preserved following seeding on SIS-ECM. In a porcine in vivo patch study, the presence of porcine MSCs on SIS-ECM significantly reduced adaptive T cell response regardless of cell dose and orientation compared to SIS-ECM alone. These findings substantiate the clinical translational potential of combined SIS-ECM seeded with MSCs as a promising therapeutic candidate for cardiac applications.
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Affiliation(s)
- Chia Wei Chang
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Tye Petrie
- Department of Surgery, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Alycia Clark
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Xin Lin
- Department of Surgery, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Claus S. Sondergaard
- Department of Surgery, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Leigh G. Griffiths
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
- * E-mail:
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29
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Soares JS, Sacks MS. A triphasic constrained mixture model of engineered tissue formation under in vitro dynamic mechanical conditioning. Biomech Model Mechanobiol 2016; 15:293-316. [PMID: 26055347 PMCID: PMC4712131 DOI: 10.1007/s10237-015-0687-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 05/21/2015] [Indexed: 10/23/2022]
Abstract
While it has become axiomatic that mechanical signals promote in vitro engineered tissue formation, the underlying mechanisms remain largely unknown. Moreover, efforts to date to determine parameters for optimal extracellular matrix (ECM) development have been largely empirical. In the present work, we propose a two-pronged approach involving novel theoretical developments coupled with key experimental data to develop better mechanistic understanding of growth and development of dense connective tissue under mechanical stimuli. To describe cellular proliferation and ECM synthesis that occur at rates of days to weeks, we employ mixture theory to model the construct constituents as a nutrient-cell-ECM triphasic system, their transport, and their biochemical reactions. Dynamic conditioning protocols with frequencies around 1 Hz are described with multi-scale methods to couple the dissimilar time scales. Enhancement of nutrient transport due to pore fluid advection is upscaled into the growth model, and the spatially dependent ECM distribution describes the evolving poroelastic characteristics of the scaffold-engineered tissue construct. Simulation results compared favorably to the existing experimental data, and most importantly, distinguish between static and dynamic conditioning regimes. The theoretical framework for mechanically conditioned tissue engineering (TE) permits not only the formulation of novel and better-informed mechanistic hypothesis describing the phenomena underlying TE growth and development, but also the exploration/optimization of conditioning protocols in a rational manner.
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Affiliation(s)
- Joao S Soares
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences (ICES), Department of Biomedical Engineering, The University of Texas at Austin, 201 East 24th Street, Austin, TX, 78712-1129, USA
| | - Michael S Sacks
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences (ICES), Department of Biomedical Engineering, The University of Texas at Austin, 201 East 24th Street, Austin, TX, 78712-1129, USA.
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30
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Lei Y, Ferdous Z. Design considerations and challenges for mechanical stretch bioreactors in tissue engineering. Biotechnol Prog 2016; 32:543-53. [PMID: 26929197 DOI: 10.1002/btpr.2256] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 02/19/2016] [Indexed: 01/05/2023]
Abstract
With the increase in average life expectancy and growing aging population, lack of functional grafts for replacement surgeries has become a severe problem. Engineered tissues are a promising alternative to this problem because they can mimic the physiological function of the native tissues and be cultured on demand. Cyclic stretch is important for developing many engineered tissues such as hearts, heart valves, muscles, and bones. Thus a variety of stretch bioreactors and corresponding scaffolds have been designed and tested to study the underlying mechanism of tissue formation and to optimize the mechanical conditions applied to the engineered tissues. In this review, we look at various designs of stretch bioreactors and common scaffolds and offer insights for future improvements in tissue engineering applications. First, we summarize the requirements and common configuration of stretch bioreactors. Next, we present the features of different actuating and motion transforming systems and their applications. Since most bioreactors must measure detailed distributions of loads and deformations on engineered tissues, techniques with high accuracy, precision, and frequency have been developed. We also cover the key points in designing culture chambers, nutrition exchanging systems, and regimens used for specific tissues. Since scaffolds are essential for providing biophysical microenvironments for residing cells, we discuss materials and technologies used in fabricating scaffolds to mimic anisotropic native tissues, including decellularized tissues, hydrogels, biocompatible polymers, electrospinning, and 3D bioprinting techniques. Finally, we present the potential future directions for improving stretch bioreactors and scaffolds. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:543-553, 2016.
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Affiliation(s)
- Ying Lei
- Dept. of Mechanical, Aerospace, and Biomedical Engineering, the University of Tennessee, Knoxville, TN, 37996
| | - Zannatul Ferdous
- Dept. of Mechanical, Aerospace, and Biomedical Engineering, the University of Tennessee, Knoxville, TN, 37996
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31
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Salinas M, Rath S, Villegas A, Unnikrishnan V, Ramaswamy S. Relative Effects of Fluid Oscillations and Nutrient Transport in the In Vitro Growth of Valvular Tissues. Cardiovasc Eng Technol 2016; 7:170-81. [PMID: 26857014 DOI: 10.1007/s13239-016-0258-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 02/01/2016] [Indexed: 12/21/2022]
Abstract
Engineered valvular tissues are cultured dynamically, and involve specimen movement. We previously demonstrated that oscillatory shear stresses (OSS) under combined steady flow and specimen cyclic flexure (flex-flow) promote tissue formation. However, localized efficiency of specimen mass transport is also important in the context of cell viability within the growing tissues. Here, we investigated the delivery of two essential species for cell survival, glucose and oxygen, to 3-dimensional (3D) engineered valvular tissues. We applied a convective-diffusive model to characterize glucose and oxygen mass transport with and without valve-like specimen flexural movement. We found the mass transport effects for glucose and oxygen to be negligible for scaffold porosities typically present during in vitro experiments and non-essential unless the porosity was unusually low (<40%). For more typical scaffold porosities (75%) however, we found negligible variation in the specimen mass fraction of glucose and oxygen in both non-moving and moving constructs (p > 0.05). Based on this result, we conducted an experiment using bone marrow stem cell (BMSC)-seeded scaffolds under Pulsatile flow-alone states to permit OSS without any specimen movement. BMSC-seeded specimen collagen from the pulsatile flow and flex-flow environments were subsequently found to be comparable (p > 0.05) and exhibited some gene expression similarities. We conclude that a critical magnitude of fluid-induced, OSS created by either pulsatile flow or flex-flow conditions, particularly when the oscillations are physiologically-relevant, is the direct, principal stimulus that promotes engineered valvular tissues and its phenotype, whereas mass transport benefits derived from specimen movement are minimal.
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Affiliation(s)
- Manuel Salinas
- Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, 10555 W. Flagler Street, EC 2612, Miami, FL, 33174, USA
| | - Sasmita Rath
- Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, 10555 W. Flagler Street, EC 2612, Miami, FL, 33174, USA
| | - Ana Villegas
- Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, 10555 W. Flagler Street, EC 2612, Miami, FL, 33174, USA
| | - Vinu Unnikrishnan
- Department of Aerospace Engineering and Mechanics, The University of Alabama, Tuscaloosa, AL, USA
| | - Sharan Ramaswamy
- Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, 10555 W. Flagler Street, EC 2612, Miami, FL, 33174, USA.
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32
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Parvin Nejad S, Blaser MC, Santerre JP, Caldarone CA, Simmons CA. Biomechanical conditioning of tissue engineered heart valves: Too much of a good thing? Adv Drug Deliv Rev 2016; 96:161-75. [PMID: 26555371 DOI: 10.1016/j.addr.2015.11.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/23/2015] [Accepted: 11/02/2015] [Indexed: 12/13/2022]
Abstract
Surgical replacement of dysfunctional valves is the primary option for the treatment of valvular disease and congenital defects. Existing mechanical and bioprosthetic replacement valves are far from ideal, requiring concomitant anticoagulation therapy or having limited durability, thus necessitating further surgical intervention. Heart valve tissue engineering (HVTE) is a promising alternative to existing replacement options, with the potential to synthesize mechanically robust tissue capable of growth, repair, and remodeling. The clinical realization of a bioengineered valve relies on the appropriate combination of cells, biomaterials, and/or bioreactor conditioning. Biomechanical conditioning of valves in vitro promotes differentiation of progenitor cells to tissue-synthesizing myofibroblasts and prepares the construct to withstand the complex hemodynamic environment of the native valve. While this is a crucial step in most HVTE strategies, it also may contribute to fibrosis, the primary limitation of engineered valves, through sustained myofibrogenesis. In this review, we examine the progress of HVTE and the role of mechanical conditioning in the synthesis of mechanically robust tissue, and suggest approaches to achieve myofibroblast quiescence and prevent fibrosis.
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33
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Rath S, Salinas M, Villegas AG, Ramaswamy S. Differentiation and Distribution of Marrow Stem Cells in Flex-Flow Environments Demonstrate Support of the Valvular Phenotype. PLoS One 2015; 10:e0141802. [PMID: 26536240 PMCID: PMC4633293 DOI: 10.1371/journal.pone.0141802] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/13/2015] [Indexed: 11/18/2022] Open
Abstract
For treatment of critical heart valve diseases, prosthetic valves perform fairly well in most adults; however, for pediatric patients, there is the added requirement that the replacement valve grows with the child, thus extremely limiting current treatment options. Tissue engineered heart valves (TEHV), such as those derived from autologous bone marrow stem cells (BMSCs), have the potential to recapitulate native valve architecture and accommodate somatic growth. However, a fundamental pre-cursor in promoting directed integration with native tissues rather than random, uncontrolled growth requires an understanding of BMSC mechanobiological responses to valve-relevant mechanical environments. Here, we report on the responses of human BMSC-seeded polymer constructs to the valve-relevant stress states of: (i) steady flow alone, (ii) cyclic flexure alone, and (iii) the combination of cyclic flexure and steady flow (flex-flow). BMSCs were seeded onto a PGA: PLLA polymer scaffold and cultured in static culture for 8 days. Subsequently, the aforementioned mechanical conditions, (groups consisting of steady flow alone-850ml/min, cyclic flexure alone-1 Hz, and flex-flow-850ml/min and 1 Hz) were applied for an additional two weeks. We found samples from the flex-flow group exhibited a valve-like distribution of cells that expressed endothelial (preference to the surfaces) and myofibroblast (preference to the intermediate region) phenotypes. We interpret that this was likely due to the presence of both appreciable fluid-induced shear stress magnitudes and oscillatory shear stresses, which were concomitantly imparted onto the samples. These results indicate that flex-flow mechanical environments support directed in vitro differentiation of BMSCs uniquely towards a heart valve phenotype, as evident by cellular distribution and expression of specific gene markers. A priori guidance of BMSC-derived, engineered tissue growth under flex-flow conditions may serve to subsequently promote controlled, engineered to native tissue integration processes in vivo necessary for successful long-term valve remodeling.
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Affiliation(s)
- Sasmita Rath
- Department of Biomedical Engineering, Florida International University, Miami, FL, 33174, United States of America
| | - Manuel Salinas
- Department of Biomedical Engineering, Florida International University, Miami, FL, 33174, United States of America
| | - Ana G. Villegas
- Department of Biomedical Engineering, Florida International University, Miami, FL, 33174, United States of America
| | - Sharan Ramaswamy
- Department of Biomedical Engineering, Florida International University, Miami, FL, 33174, United States of America
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Abstract
Heart disease, including valve pathologies, is the leading cause of death worldwide. Despite the progress made thanks to improving transplantation techniques, a perfect valve substitute has not yet been developed: once a diseased valve is replaced with current technologies, the newly implanted valve still needs to be changed some time in the future. This situation is particularly dramatic in the case of children and young adults, because of the necessity of valve growth during the patient's life. Our review focuses on the current status of heart valve (HV) therapy and the challenges that must be solved in the development of new approaches based on tissue engineering. Scientists and physicians have proposed tissue-engineered heart valves (TEHVs) as the most promising solution for HV replacement, especially given that they can help to avoid thrombosis, structural deterioration and xenoinfections. Lastly, TEHVs might also serve as a model for studying human valve development and pathologies.
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35
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Avolio E, Caputo M, Madeddu P. Stem cell therapy and tissue engineering for correction of congenital heart disease. Front Cell Dev Biol 2015; 3:39. [PMID: 26176009 PMCID: PMC4485350 DOI: 10.3389/fcell.2015.00039] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 06/10/2015] [Indexed: 01/08/2023] Open
Abstract
This review article reports on the new field of stem cell therapy and tissue engineering and its potential on the management of congenital heart disease. To date, stem cell therapy has mainly focused on treatment of ischemic heart disease and heart failure, with initial indication of safety and mild-to-moderate efficacy. Preclinical studies and initial clinical trials suggest that the approach could be uniquely suited for the correction of congenital defects of the heart. The basic concept is to create living material made by cellularized grafts that, once implanted into the heart, grows and remodels in parallel with the recipient organ. This would make a substantial improvement in current clinical management, which often requires repeated surgical corrections for failure of implanted grafts. Different types of stem cells have been considered and the identification of specific cardiac stem cells within the heterogeneous population of mesenchymal and stromal cells offers opportunities for de novo cardiomyogenesis. In addition, endothelial cells and vascular progenitors, including cells with pericyte characteristics, may be necessary to generate efficiently perfused grafts. The implementation of current surgical grafts by stem cell engineering could address the unmet clinical needs of patients with congenital heart defects.
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Affiliation(s)
- Elisa Avolio
- Division of Experimental Cardiovascular Medicine, School of Clinical Sciences, Bristol Heart Institute, University of Bristol Bristol, UK
| | - Massimo Caputo
- Congenital Heart Surgery, School of Clinical Sciences, Bristol Heart Institute, University of Bristol Bristol, UK
| | - Paolo Madeddu
- Division of Experimental Cardiovascular Medicine, School of Clinical Sciences, Bristol Heart Institute, University of Bristol Bristol, UK
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36
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Balaoing LR, Post AD, Lin AY, Tseng H, Moake JL, Grande-Allen KJ. Laminin Peptide-Immobilized Hydrogels Modulate Valve Endothelial Cell Hemostatic Regulation. PLoS One 2015; 10:e0130749. [PMID: 26090873 PMCID: PMC4474637 DOI: 10.1371/journal.pone.0130749] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/23/2015] [Indexed: 11/18/2022] Open
Abstract
Valve endothelial cells (VEC) have unique phenotypic responses relative to other types of vascular endothelial cells and have highly sensitive hemostatic functions affected by changes in valve tissues. Furthermore, effects of environmental factors on VEC hemostatic function has not been characterized. This work used a poly(ethylene glycol) diacrylate (PEGDA) hydrogel platform to evaluate the effects of substrate stiffness and cell adhesive ligands on VEC phenotype and expression of hemostatic genes. Hydrogels of molecular weights (MWs) 3.4, 8, and 20 kDa were polymerized into platforms of different rigidities and thiol-modified cell adhesive peptides were covalently bound to acrylate groups on the hydrogel surfaces. The peptide RKRLQVQLSIRT (RKR) is a syndecan-1 binding ligand derived from laminin, a trimeric protein and a basement membrane matrix component. Conversely, RGDS is an integrin binding peptide found in many extracellular matrix (ECM) proteins including fibronectin, fibrinogen, and von Willebrand factor (VWF). VECs adhered to and formed a stable monolayer on all RKR-coated hydrogel-MW combinations. RGDS-coated platforms supported VEC adhesion and growth on RGDS-3.4 kDa and RGDS-8 kDa hydrogels. VECs cultured on the softer RKR-8 kDa and RKR-20 kDa hydrogel platforms had significantly higher gene expression for all anti-thrombotic (ADAMTS-13, tissue factor pathway inhibitor, and tissue plasminogen activator) and thrombotic (VWF, tissue factor, and P-selectin) proteins than VECs cultured on RGDS-coated hydrogels and tissue culture polystyrene controls. Stimulated VECs promoted greater platelet adhesion than non-stimulated VECs on their respective culture condition; yet stimulated VECs on RGDS-3.4 kDa gels were not as responsive to stimulation relative to the RKR-gel groups. Thus, the syndecan binding, laminin-derived peptide promoted stable VEC adhesion on the softer hydrogels and maintained VEC phenotype and natural hemostatic function. In conclusion, utilization of non-integrin adhesive peptide sequences derived from basement membrane ECM may recapitulate balanced VEC function and may benefit endothelialization of valve implants.
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Affiliation(s)
- Liezl Rae Balaoing
- Department of Bioengineering, Rice University, Houston, TX, 77005, United States of America
| | - Allison Davis Post
- Department of Bioengineering, Rice University, Houston, TX, 77005, United States of America
| | - Adam Yuh Lin
- Department of Bioengineering, Rice University, Houston, TX, 77005, United States of America
| | - Hubert Tseng
- Department of Bioengineering, Rice University, Houston, TX, 77005, United States of America
| | - Joel L. Moake
- Department of Bioengineering, Rice University, Houston, TX, 77005, United States of America
| | - K. Jane Grande-Allen
- Department of Bioengineering, Rice University, Houston, TX, 77005, United States of America
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37
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Ramaswamy S, Boronyak SM, Le T, Holmes A, Sotiropoulos F, Sacks MS. A novel bioreactor for mechanobiological studies of engineered heart valve tissue formation under pulmonary arterial physiological flow conditions. J Biomech Eng 2015; 136:121009. [PMID: 25321615 DOI: 10.1115/1.4028815] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Accepted: 10/16/2014] [Indexed: 02/04/2023]
Abstract
The ability to replicate physiological hemodynamic conditions during in vitro tissue development has been recognized as an important aspect in the development and in vitro assessment of engineered heart valve tissues. Moreover, we have demonstrated that studies aiming to understand mechanical conditioning require separation of the major heart valve deformation loading modes: flow, stretch, and flexure (FSF) (Sacks et al., 2009, "Bioengineering Challenges for Heart Valve Tissue Engineering," Annu. Rev. Biomed. Eng., 11(1), pp. 289-313). To achieve these goals in a novel bioreactor design, we utilized a cylindrical conduit configuration for the conditioning chamber to allow for higher fluid velocities, translating to higher shear stresses on the in situ tissue specimens while retaining laminar flow conditions. Moving boundary computational fluid dynamic (CFD) simulations were performed to predict the flow field under combined cyclic flexure and steady flow (cyclic-flex-flow) states using various combinations of flow rate, and media viscosity. The device was successfully constructed and tested for incubator housing, gas exchange, and sterility. In addition, we performed a pilot experiment using biodegradable polymer scaffolds seeded with bone marrow derived stem cells (BMSCs) at a seeding density of 5 × 10(6) cells/cm(2). The constructs were subjected to combined cyclic flexure (1 Hz frequency) and steady flow (Re = 1376; flow rate of 1.06 l/min (LPM); shear stress in the range of 0-9 dynes/cm(2) for 2 weeks to permit physiological shear stress conditions. Assays revealed significantly (P < 0.05) higher amounts of collagen (2051 ± 256 μg/g) at the end of 2 weeks in comparison to similar experiments previously conducted in our laboratory but performed at subphysiological levels of shear stress (<2 dynes/cm(2); Engelmayr et al., 2006, "Cyclic Flexure and Laminar Flow Synergistically Accelerate Mesenchymal Stem Cell-Mediated Engineered Tissue Formation: Implications for Engineered Heart Valve Tissues," Biomaterials, 27(36), pp. 6083-6095). The implications of this novel design are that fully coupled or decoupled physiological flow, flexure, and stretch modes of engineered tissue conditioning investigations can be readily accomplished with the inclusion of this device in experimental protocols on engineered heart valve tissue formation.
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38
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Hobson CM, Amoroso NJ, Amini R, Ungchusri E, Hong Y, D'Amore A, Sacks MS, Wagner WR. Fabrication of elastomeric scaffolds with curvilinear fibrous structures for heart valve leaflet engineering. J Biomed Mater Res A 2015; 103:3101-6. [PMID: 25771748 DOI: 10.1002/jbm.a.35450] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/13/2015] [Accepted: 02/27/2015] [Indexed: 01/10/2023]
Abstract
Native semi-lunar heart valves are composed of a dense fibrous network that generally follows a curvilinear path along the width of the leaflet. Recent models of engineered valve leaflets have predicted that such curvilinear fiber orientations would homogenize the strain field and reduce stress concentrations at the commissure. In the present work, a method was developed to reproduce this curvilinear fiber alignment in electrospun scaffolds by varying the geometry of the collecting mandrel. Elastomeric poly(ester urethane)urea was electrospun onto rotating conical mandrels of varying angles to produce fibrous scaffolds where the angle of fiber alignment varied linearly over scaffold length. By matching the radius of the conical mandrel to the radius of curvature for the native pulmonary valve, the electrospun constructs exhibited a curvilinear fiber structure similar to the native leaflet. Moreover, the constructs had local mechanical properties comparable to conventional scaffolds and native heart valves. In agreement with prior modeling results, it was found under quasi-static loading that curvilinear fiber microstructures reduced strain concentrations compared to scaffolds generated on a conventional cylindrical mandrels. Thus, this simple technique offers an attractive means for fabricating scaffolds where key microstructural features of the native leaflet are imitated for heart valve tissue engineering.
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Affiliation(s)
- Christopher M Hobson
- Bioengineering and Surgery, McGowan Institute for Regenerative Medicine.,Department of Bioengineering
| | - Nicholas J Amoroso
- Bioengineering and Surgery, McGowan Institute for Regenerative Medicine.,Department of Surgery
| | - Rouzbeh Amini
- Department of Biomedical Engineering, the University of Akron, Ohio
| | - Ethan Ungchusri
- Bioengineering and Surgery, McGowan Institute for Regenerative Medicine
| | - Yi Hong
- Bioengineering and Surgery, McGowan Institute for Regenerative Medicine.,Department of Bioengineering, University of Texas at Arlington, Arlington, Texas, 76019
| | - Antonio D'Amore
- Bioengineering and Surgery, McGowan Institute for Regenerative Medicine.,Department of Bioengineering.,Department of Surgery.,Foundation RiMED, Palermo, Italy.,DICGIM, University of Palermo, Palermo, Italy
| | - Michael S Sacks
- Center for Cardiovascular Simulation, Institute for Computational Engineering and Sciences, Department of Biomedical Engineering and the University of Texas at Austin, Austin, Texas
| | - William R Wagner
- Bioengineering and Surgery, McGowan Institute for Regenerative Medicine.,Department of Bioengineering.,Department of Surgery.,Department of Chemical Engineering, University of Pittsburgh, Pennsylvania
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39
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Dan P, Velot É, Decot V, Menu P. The role of mechanical stimuli in the vascular differentiation of mesenchymal stem cells. J Cell Sci 2015; 128:2415-22. [DOI: 10.1242/jcs.167783] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are among the most promising and suitable stem cell types for vascular tissue engineering. Substantial effort has been made to differentiate MSCs towards vascular cell phenotypes, including endothelial cells and smooth muscle cells (SMCs). The microenvironment of vascular cells not only contains biochemical factors that influence differentiation, but also exerts hemodynamic forces, such as shear stress and cyclic strain. Recent evidence has shown that these forces can influence the differentiation of MSCs into endothelial cells or SMCs. In this Commentary, we present the main findings in the area with the aim of summarizing the mechanisms by which shear stress and cyclic strain induce MSC differentiation. We will also discuss the interactions between these mechanical cues and other components of the microenvironment, and highlight how these insights could be used to maintain differentiation.
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Affiliation(s)
- Pan Dan
- UMR 7365 CNRS Université de Lorraine, Ingenierie Moleculaire et Physiopathologie Articulaire, Department of Cell and Tissue Engineering, Vectorization, Imaging, Biopôle de l'Université de Lorraine, Avenue de la forêt de Haye, C.S. 50184, Vandœuvre-lès-Nancy Cedex F-54505, France
- Department of Thoracic and Cardiovascular surgery, Zhongnan hospital of Wuhan University, Wuhan, 430071, China
| | - Émilie Velot
- UMR 7365 CNRS Université de Lorraine, Ingenierie Moleculaire et Physiopathologie Articulaire, Department of Cell and Tissue Engineering, Vectorization, Imaging, Biopôle de l'Université de Lorraine, Avenue de la forêt de Haye, C.S. 50184, Vandœuvre-lès-Nancy Cedex F-54505, France
| | - Véronique Decot
- UMR 7365 CNRS Université de Lorraine, Ingenierie Moleculaire et Physiopathologie Articulaire, Department of Cell and Tissue Engineering, Vectorization, Imaging, Biopôle de l'Université de Lorraine, Avenue de la forêt de Haye, C.S. 50184, Vandœuvre-lès-Nancy Cedex F-54505, France
- CHU de Nancy, Unité de Thérapie Cellulaire et Tissus, allée du Morvan, Vandœuvre-lès-Nancy F-54500, France
| | - Patrick Menu
- UMR 7365 CNRS Université de Lorraine, Ingenierie Moleculaire et Physiopathologie Articulaire, Department of Cell and Tissue Engineering, Vectorization, Imaging, Biopôle de l'Université de Lorraine, Avenue de la forêt de Haye, C.S. 50184, Vandœuvre-lès-Nancy Cedex F-54505, France
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40
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Salinas M, Ramaswamy S. Computational simulations predict a key role for oscillatory fluid shear stress in de novo valvular tissue formation. J Biomech 2014; 47:3517-23. [PMID: 25262874 DOI: 10.1016/j.jbiomech.2014.08.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 08/19/2014] [Accepted: 08/24/2014] [Indexed: 10/24/2022]
Abstract
Previous efforts in heart valve tissue engineering demonstrated that the combined effect of cyclic flexure and steady flow on bone marrow derived stem cell-seeded scaffolds resulted in significant increases in engineered collagen formation [Engelmayr et al. Cyclic flexure and laminar flow synergistically accelerate mesenchymal stem cell-mediated engineered tissue formation: Implications for engineered heart valve tissues. Biomaterials 2006; 27(36): 6083-95]. Here, we provide a new interpretation for the underlying reason for this observed effect. In addition, another related investigation demonstrated the impact of fluid flow on DNA content and quantified the fluid-induced shear stresses on the engineered heart valve tissue specimens [Engelmayr et al. A Novel Flex-Stretch-Flow Bioreactor for the Study of Engineered Heart Valve Tissue Mechanobiology]. Annals of Biomedical Engineering 2008, 36, 1-13]. In this study, we performed more advanced CFD analysis with an emphasis on oscillatory wall shear stresses imparted on specimens when mechanically conditioned by a combination of cyclic flexure and steady flow. Specifically, we hypothesized that the dominant stimulatory regulator of the bone marrow stem cells is fluid-induced and depends on both the magnitude and temporal directionality of surface stresses, i.e., oscillatory shear stresses (OSS) acting on the developing tissues. Therefore, we computationally quantified the (i) magnitude of fluid-induced shear stresses as well as (ii) the extent of temporal fluid oscillations in the flow field using the oscillatory shear index (OSI) parameter. Noting that sample cyclic flexure induces a high degree of OSS, we incorporated moving boundary computational fluid dynamic simulations of samples housed within a bioreactor to consider the effects of: (1) No Flow, No Flexure (control group), (2) Steady Flow-alone, (3) Cyclic Flexure-alone and (4) Combined Steady flow and Cyclic Flexure environments. Indeed we found that the coexistence of both OSS and appreciable shear stress magnitudes explained the high levels of engineered collagen previously observed from combining cyclic flexure and steady flow states. On the other hand, each of these metrics on its own showed no association. This finding suggests that cyclic flexure and steady flow synergistically promote engineered heart valve tissue production via OSS, so long as the oscillations are accompanied by a critical magnitude of shear stress.
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Affiliation(s)
- Manuel Salinas
- Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | - Sharan Ramaswamy
- Tissue Engineering, Mechanics, Imaging, and Materials Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA.
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Masoumi N, Howell MC, Johnson KL, Niesslein MJ, Gerber G, Engelmayr GC. Design and testing of a cyclic stretch and flexure bioreactor for evaluating engineered heart valve tissues based on poly(glycerol sebacate) scaffolds. Proc Inst Mech Eng H 2014; 228:576-586. [PMID: 24898445 DOI: 10.1177/0954411914534837] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cyclic flexure and stretch are essential to the function of semilunar heart valves and have demonstrated utility in mechanically conditioning tissue-engineered heart valves. In this study, a cyclic stretch and flexure bioreactor was designed and tested in the context of the bioresorbable elastomer poly(glycerol sebacate). Solid poly(glycerol sebacate) membranes were subjected to cyclic stretch, and micromolded poly(glycerol sebacate) scaffolds seeded with porcine aortic valvular interstitial cells were subjected to cyclic stretch and flexure. The results demonstrated significant effects of cyclic stretch on poly(glycerol sebacate) mechanical properties, including significant decreases in effective stiffness versus controls. In valvular interstitial cell-seeded scaffolds, cyclic stretch elicited significant increases in DNA and collagen content that paralleled maintenance of effective stiffness. This work provides a basis for investigating the roles of mechanical loading in the formation of tissue-engineered heart valves based on elastomeric scaffolds.
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Affiliation(s)
- Nafiseh Masoumi
- Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA
| | - M Christian Howell
- Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA
| | - Katherine L Johnson
- Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA
| | - Matthew J Niesslein
- Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA
| | - Gene Gerber
- Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA
| | - George C Engelmayr
- Department of Bioengineering, The Pennsylvania State University, University Park, PA, USA
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42
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Biomechanical properties of native and tissue engineered heart valve constructs. J Biomech 2014; 47:1949-63. [DOI: 10.1016/j.jbiomech.2013.09.023] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/09/2013] [Accepted: 09/10/2013] [Indexed: 11/18/2022]
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43
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Soares JS, B Le T, Sotiropoulos F, S Sacks M. Modeling the Role of Oscillator Flow and Dynamic Mechanical Conditioning on Dense Connective Tissue Formation in Mesenchymal Stem Cell-Derived Heart Valve Tissue Engineering. J Med Device 2013; 7:0409271-409272. [PMID: 24895524 DOI: 10.1115/1.4025984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 11/05/2013] [Indexed: 11/08/2022] Open
Affiliation(s)
- João S Soares
- Institute for Computational Engineering and Sciences, University of Texas at Austin , Austin, TX 78712
| | | | - Fotis Sotiropoulos
- Saint Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota , Minneapolis, MN 55414
| | - Michael S Sacks
- Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, University of Texas at Austin , Austin, TX 78712
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44
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Qiu J, Zheng Y, Hu J, Liao D, Gregersen H, Deng X, Fan Y, Wang G. Biomechanical regulation of vascular smooth muscle cell functions: from in vitro to in vivo understanding. J R Soc Interface 2013; 11:20130852. [PMID: 24152813 DOI: 10.1098/rsif.2013.0852] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Vascular smooth muscle cells (VSMCs) have critical functions in vascular diseases. Haemodynamic factors are important regulators of VSMC functions in vascular pathophysiology. VSMCs are physiologically active in the three-dimensional matrix and interact with the shear stress sensor of endothelial cells (ECs). The purpose of this review is to illustrate how haemodynamic factors regulate VSMC functions under two-dimensional conditions in vitro or three-dimensional co-culture conditions in vivo. Recent advances show that high shear stress induces VSMC apoptosis through endothelial-released nitric oxide and low shear stress upregulates VSMC proliferation and migration through platelet-derived growth factor released by ECs. This differential regulation emphasizes the need to construct more actual environments for future research on vascular diseases (such as atherosclerosis and hypertension) and cardiovascular tissue engineering.
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Affiliation(s)
- Juhui Qiu
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Chongqing Engineering Laboratory in Vascular Implants, College of Bioengineering, Chongqing University, , Chongqing 400044, People's Republic of China
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45
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Jung S, Panchalingam KM, Wuerth RD, Rosenberg L, Behie LA. Large-scale production of human mesenchymal stem cells for clinical applications. Biotechnol Appl Biochem 2013; 59:106-20. [PMID: 23586791 DOI: 10.1002/bab.1006] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 01/30/2012] [Indexed: 02/06/2023]
Abstract
Human mesenchymal stem cells (hMSCs) have many potential applications in tissue engineering and regenerative medicine. Currently, hMSCs are generated through conventional static adherent cultures in the presence of fetal bovine serum (FBS) for clinical applications (e.g., multiple sclerosis). However, these methods are not appropriate to meet the expected future demand for quality-assured hMSCs for human therapeutic use. Hence, it is imperative to develop an effective hMSC production system, which should be controllable, reproducible, and scalable. To this end, efforts have been made by several international research groups to develop (i) alternative media either by replacing FBS with human-sourced supplements (such as human serum or platelet lysate) or by identifying defined serum-free formulations consisting of key growth/attachment factors, and (ii) controlled bioreactor protocols. In this regard, we review here current hMSC production technologies and future perspectives toward efficient methods for the generation of clinically relevant numbers of hMSC therapeutics.
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Affiliation(s)
- Sunghoon Jung
- Pharmaceutical Production Research Facility, Schulich School of Engineering, University of Calgary, Calgary, Alberta, Canada
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46
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Martinez C, Henao A, Rodriguez JE, Padgett KR, Ramaswamy S. Monitoring Steady Flow Effects on Cell Distribution in Engineered Valve Tissues by Magnetic Resonance Imaging. Mol Imaging 2013. [DOI: 10.2310/7290.2013.00063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Catalina Martinez
- From the Tissue Engineering Mechanics, Imaging and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, and Interdisciplinary Stem Cell Institute and Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL
| | - Angela Henao
- From the Tissue Engineering Mechanics, Imaging and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, and Interdisciplinary Stem Cell Institute and Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL
| | - Jose E. Rodriguez
- From the Tissue Engineering Mechanics, Imaging and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, and Interdisciplinary Stem Cell Institute and Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL
| | - Kyle R. Padgett
- From the Tissue Engineering Mechanics, Imaging and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, and Interdisciplinary Stem Cell Institute and Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL
| | - Sharan Ramaswamy
- From the Tissue Engineering Mechanics, Imaging and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, and Interdisciplinary Stem Cell Institute and Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL
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47
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Glycosaminoglycan entrapment by fibrin in engineered heart valve tissues. Acta Biomater 2013; 9:8149-57. [PMID: 23791855 DOI: 10.1016/j.actbio.2013.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 05/27/2013] [Accepted: 06/06/2013] [Indexed: 02/05/2023]
Abstract
Tissue engineered heart valves (TEHVs) may provide a permanent solution to congenital heart valve disease by permitting somatic valve growth in the pediatric patient. However, to date, TEHV studies have focused primarily on collagen, the dominant component of valve extracellular matrix (ECM). Temporal decreases in other ECM components, such as the glycosaminoglycans (GAGs), generally decrease as cells produce more collagen under mechanically loaded states; nevertheless, GAGs represent a key component of the valve ECM, providing structural stability and hydration to the leaflets. In an effort to retain GAGs within the engineered constructs, here we investigated the utility of the protein fibrin in combination with a valve-like, cyclic flexure and steady flow (flex-flow) mechanical conditioning culture process using adult human periodontal ligament cells (PLCs). We found both fibrin and flex-flow mechanical components to be independently significant (p<0.05), and hence important in influencing the DNA, GAG and collagen contents of the engineered tissues. In addition, the interaction of fibrin with flex-flow was found to be significant in the case of collagen; specifically, the combination of these environments promoted PLC collagen production resulting in a significant difference compared to dynamic and statically cultured specimens without fibrin. Histological examination revealed that the GAGs were retained by fibrin entrapment and adhesion, which were subsequently confirmed by additional experiments on native valve tissues. We conclude that fibrin in the flex-flow culture of engineered heart valve tissues: (i) augments PLC-derived collagen production; and (ii) enhances retention of GAGs within the developing ECM.
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48
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Spoon DB, Tefft BJ, Lerman A, Simari RD. Challenges of biological valve development. Interv Cardiol 2013. [DOI: 10.2217/ica.13.21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Masoumi N, Johnson KL, Howell MC, Engelmayr GC. Valvular interstitial cell seeded poly(glycerol sebacate) scaffolds: toward a biomimetic in vitro model for heart valve tissue engineering. Acta Biomater 2013; 9:5974-88. [PMID: 23295404 DOI: 10.1016/j.actbio.2013.01.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 11/24/2012] [Accepted: 01/01/2013] [Indexed: 01/01/2023]
Abstract
Tissue engineered replacement heart valves may be capable of overcoming the lack of growth potential intrinsic to current non-viable prosthetics, and thus could potentially serve as permanent replacements in the surgical repair of pediatric valvular lesions. However, the evaluation of candidate combinations of cells and scaffolds lacks a biomimetic in vitro model with broadly tunable, anisotropic and elastomeric structural-mechanical properties. Toward establishing such an in vitro model, in the current study, porcine aortic and pulmonary valvular interstitial cells (i.e. biomimetic cells) were cultivated on anisotropic, micromolded poly(glycerol sebacate) scaffolds (i.e. biomimetic scaffolds). Following 14 and 28 days of static culture, cell-seeded scaffolds and unseeded controls were assessed for their mechanical properties, and cell-seeded scaffolds were further characterized by confocal fluorescence and scanning electron microscopy, and by collagen and DNA assays. Poly(glycerol sebacate) micromolding yielded scaffolds with anisotropic stiffnesses resembling those of native valvular tissues in the low stress-strain ranges characteristic of physiologic valvular function. Scaffold anisotropy was largely retained upon cultivation with valvular interstitial cells; while the mechanical properties of unseeded scaffolds progressively diminished, cell-seeded scaffolds either retained or exceeded initial mechanical properties. Retention of mechanical properties in cell-seeded scaffolds paralleled the accretion of collagen, which increased significantly from 14 to 28 days. This study demonstrates that valvular interstitial cells can be cultivated on anisotropic poly(glycerol sebacate) scaffolds to yield biomimetic in vitro models with which clinically relevant cells and future scaffold designs can be evaluated.
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50
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Martinez C, Rath S, Van Gulden S, Pelaez D, Alfonso A, Fernandez N, Kos L, Cheung H, Ramaswamy S. Periodontal ligament cells cultured under steady-flow environments demonstrate potential for use in heart valve tissue engineering. Tissue Eng Part A 2012; 19:458-66. [PMID: 22958144 DOI: 10.1089/ten.tea.2012.0149] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A major drawback of mechanical and prosthetic heart valves is their inability to permit somatic growth. By contrast, tissue-engineered pulmonary valves potentially have the capacity to remodel and integrate with the patient. For this purpose, adult stem cells may be suitable. Previously, human periodontal ligament cells (PDLs) have been explored as a reliable and robust progenitor cell source for cardiac muscle regeneration (Pelaez, D. Electronic Thesis and Dissertation Database, Coral Gables, FL, May 2011). Here, we investigate the potential of PDLs to support the valve lineage, specifically the concomitant differentiation to both endothelial cell (EC) and smooth muscle cell (SMC) types. We were able to successfully promote PDL differentiation to both SMC and EC phenotypes through a combination of stimulatory approaches using biochemical and mechanical flow conditioning (steady shear stress of 1 dyne/cm(2)), with flow-based mechanical conditioning having a predominant effect on PDL differentiation, particularly to ECs; in addition, strong expression of the marker FZD2 and an absence of the marker MLC1F point toward a unique manifestation of smooth muscle by PDLs after undergoing steady-flow mechanical conditioning alone, possible by only the heart valve and pericardium phenotypes. It was also determined that steady flow (which was performed using a physiologically relevant [for heart valves] magnitude of ~5-6 dynes/cm(2)) augmented the synthesis of the extracellular matrix collagen proteins. We conclude that under steady-flow dynamic culture environments, human PDLs can differentiate to heterogeneous cell populations that are relevant to heart valve tissue engineering. Further exploration of human PDLs for this purpose is thus warranted.
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Affiliation(s)
- Catalina Martinez
- Tissue Engineering Mechanics, Imaging and Materials Laboratory, Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, Miami, Florida 33174, USA
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