Basic Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Aug 26, 2022; 14(8): 633-657
Published online Aug 26, 2022. doi: 10.4252/wjsc.v14.i8.633
Combination of mesenchymal stem cells and three-dimensional collagen scaffold preserves ventricular remodeling in rat myocardial infarction model
Rida-e-Maria Qazi, Irfan Khan, Kanwal Haneef, Tuba Shakil Malick, Nadia Naeem, Waqas Ahmad, Asmat Salim, Sadia Mohsin
Rida-e-Maria Qazi, Irfan Khan, Tuba Shakil Malick, Waqas Ahmad, Asmat Salim, Stem Cell Laboratory, Dr. Panjwani Center for Molecular Medicine and Drug Research, ICCBS, University of Karachi, Karachi 75270, Sindh, Pakistan
Kanwal Haneef, Dr.Zafar H. Zaidi Center for Proteomics, University of Karachi, Karachi 75270, Sindh, Pakistan
Nadia Naeem, Dow Research Institute of Biotechnology and Biomedical Sciences (DRIBBS), Dow University of Health and Sciences, Ojha Campus, Karachi 74200, Sindh, Pakistan
Sadia Mohsin, Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, United States
Author contributions: Qazi REM performed all experiments, analyzed the data and wrote the first draft of the manuscript; Khan I co-supervised the research study, provided technical guidance for in vivo experiments; Haneef K provided technical guidance for in vitro 3D culture and wrote part of the manuscript; Malick TS performed some of the experiments; Naeem N and Ahmad W helped in echocardiographic analysis; Salim A conceived the idea, designed and supervised the research study and wrote the final manuscript; Mohsin S co-supervised the research study and provided overall technical guidance; all authors approved the final version of the manuscript.
Institutional review board statement: Human subjects have not been used in this study.
Institutional animal care and use committee statement: Ethical approval was obtained from the Institutional Animal Care and Use Committee (IACUC), Dr. Panjwani Center for Molecular Medicine and Drug Research (PCMD), International Center for Chemical and Biological Sciences (ICCBS), University of Karachi. Experimental procedures were carried out according to the international guidelines for care and use of laboratory animals under protocol number 2020-006.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: There is no additional data.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Asmat Salim, PhD, Professor, Stem Cell Laboratory, Dr. Panjwani Center for Molecular Medicine and Drug Research, ICCBS, University of Karachi, Main University Road, Karachi 75270, Sindh, Pakistan.
Received: March 18, 2022
Peer-review started: March 18, 2022
First decision: April 25, 2022
Revised: May 9, 2022
Accepted: July 8, 2022
Article in press: July 8, 2022
Published online: August 26, 2022

Cardiovascular diseases are the major cause of mortality worldwide. Regeneration of the damaged myocardium remains a challenge due to mechanical constraints and limited healing ability of the adult heart tissue. Cardiac tissue engineering using biomaterial scaffolds combined with stem cells and bioactive molecules could be a highly promising approach for cardiac repair. Use of biomaterials can provide suitable microenvironment to the cells and can solve cell engraftment problems associated with cell transplantation alone. Mesenchymal stem cells (MSCs) are potential candidates in cardiac tissue engineering because of their multilineage differentiation potential and ease of isolation. Use of DNA methyl transferase inhibitor, such as zebularine, in combination with three-dimensional (3D) scaffold can promote efficient MSC differentiation into cardiac lineage, as epigenetic modifications play a fundamental role in determining cell fate and lineage specific gene expression.


To investigate the role of collagen scaffold and zebularine in the differentiation of rat bone marrow (BM)-MSCs and their subsequent in vivo effects.


MSCs were isolated from rat BM and characterized morphologically, immunophenotypically and by multilineage differentiation potential. MSCs were seeded in collagen scaffold and treated with 3 μmol/L zebularine in three different ways. Cytotoxicity analysis was done and cardiac differentiation was analyzed at the gene and protein levels. Treated and untreated MSC-seeded scaffolds were transplanted in the rat myocardial infarction (MI) model and cardiac function was assessed by echocardiography. Cell tracking was performed by DiI dye labeling, while regeneration and neovascularization were evaluated by histological and immunohistochemical analysis, respectively.


MSCs were successfully isolated and seeded in collagen scaffold. Cytotoxicity analysis revealed that zebularine was not cytotoxic in any of the treatment groups. Cardiac differentiation analysis showed more pronounced results in the type 3 treatment group which was subsequently chosen for the transplantation in the in vivo MI model. Significant improvement in cardiac function was observed in the zebularine treated MSC-seeded scaffold group as compared to the MI control. Histological analysis also showed reduction in fibrotic scar, improvement in left ventricular wall thickness and preservation of ventricular remodeling in the zebularine treated MSC-seeded scaffold group. Immunohistochemical analysis revealed significant expression of cardiac proteins in DiI labeled transplanted cells and a significant increase in the number of blood vessels in the zebularine treated MSC-seeded collagen scaffold transplanted group.


Combination of 3D collagen scaffold and zebularine treatment enhances cardiac differentiation potential of MSCs, improves cell engraftment at the infarcted region, reduces infarct size and improves cardiac function.

Keywords: Mesenchymal stem cells, Myocardial infarction, Cardiac tissue engineering, Demethylating agent, Collagen scaffold, Zebularine

Core Tip: This study was designed to elucidate the effect of the three-dimensional (3D) microenvironment provided by the use of natural collagen-based scaffold and DNA methyl transferase inhibitor, zebularine, on the cardiac differentiation of mesenchymal stem cells (MSCs) in vitro and cardiac regeneration in vivo. Collagen scaffold provides a native 3D microenvironment to MSCs and along with zebularine, enhances their cardiac differentiation potential. Transplantation of zebularine treated MSC-seeded collagen scaffold in the rat myocardial infarction (MI) model aids in improving cardiac function and preserves left ventricular remodeling. Translation of this research into clinics can be a better option for the treatment of MI.