• cell proliferation
• collagen scaffold
• gelation conditions
• multi-channel structure
• perfusion culture
• tissue engineering

• 22K12821 Japan Society for the Promotion of Science

• Tissue engineering
• bioartificial testis
• fibre
• hydrogels
• male infertility
• scaffolds

• Male
• Humans
• Tissue Engineering
• Testis
• Seminiferous Tubules/metabolism
• Spermatogenesis/physiology
• Infertility, Male/therapy

A new nerve matrix membrane derived from decellularized porcine nerves has been shown to retain the major extracellular matrix components, and to be effective in preventing adhesion between the nerve anastomosis sites and the surrounding tissues in a rat sciatic nerve transection model, thereby enhancing regeneration of the nerve. The effectiveness of the membrane may be attributed to its various bioactive components. In this prospective, randomized, single-blind, parallel-controlled multicenter clinical trial, we compared the safety and efficacy of the new nerve matrix membrane with a previously approved bovine tendon-derived type I collagen nerve wrapping. A total of 120 patients with peripheral nerve injury were recruited from Beijing Jishuitan Hospital, The First Bethune Hospital of Jilin University, and Yantai Yuhuangding Hospital, China. The patients were randomly assigned to undergo end-to-end and tension-free neurorrhaphy with nerve matrix membrane (n = 60, 52 male, 8 female, mean age 41.34 years, experimental group) or tendon-derived collagen nerve wrapping (n = 60, 42 male, 18 female, mean age 40.17 years, control group). Patients were followed-up at 14 ± 5, 30 ± 7, 90 ± 10 and 180 ± 20 days after the operation. Safety evaluation included analyses of local and systemic reactions, related laboratory tests, and adverse reactions. Efficacy evaluation included a static 2-point discrimination test, a moving 2-point discrimination test, and a Semmes–Weinstein monofilament examination. Sensory nerve function was evaluated with the British Medical Research Council Scale and Semmes–Weinstein monofilament examination. The ratio (percentage) of patients with excellent to good results in sensory nerve recovery 180 ± 20 days after the treatment was used as the primary effectiveness index. The percentages of patients with excellent to good results in the experimental and control groups were 98.00% and 94.44%, respectively, with no significant difference between the two groups. There were no significant differences in the results of routine blood tests, liver and renal function tests, coagulation function tests, or immunoglobulin tests at 14 and 180 days postoperatively between the two groups. These findings suggest that the novel nerve matrix membrane is similar in efficacy to the commercially-available bovine-derived collagen membrane in the repair of peripheral nerve injury, and it may therefore serve as an alternative in the clinical setting. The clinical trial was approved by the Institutional Ethics Committee of Beijing Jishuitan Hospital, China (approval No. 20160902) on October 8, 2016, the Institutional Ethics Committee of the First Bethune Hospital of Jilin University, China (approval No. 160518-088) on December 14, 2016, and the Institutional Ethics Committee of Yantai Yuhuangding Hospital, China (approval No. 2016-10-01) on December 9, 2016. The clinical trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2000033324) on May 28, 2020.

• clinical trial
• extracellular matrix
• nerve conduit
• nerve matrix
• nerve repair
• neural regeneration
• neurorrhaphy
• peripheral nerve injury
• sensory nerve recovery

• biomaterials
• equine
• medical devices
• type I collagen

• Cell
• dexamethasone
• membrane
• repair
• sciatic nerve

• fibers
• reinforce
• scaffolds
• soft tissue

• axonotmesis
• carbon nanotubes
• functional analysis
• morphometric analysis
• nerve regeneration
• nerve-guides
• neurogenic atrophy
• polypyrrole
• polyvinyl alcohol

• alveolar bone loss
• dental implants
• mandibular nerve
• somatosensory disorders

Cytidine 5′-diphosphocholine (citicoline) has been shown to have beneficial effects in central nervous system injury as well as in motoric functional recovery after peripheral nerve injury. This study aimed to examine the effect of citicoline on prevention of neuropathic pain in a rat model of sciatic nerve crush injury.

Forty experimental rats were divided into four groups. In three groups, the right sciatic nerves were crushed in the mid-thigh region, and a gelatin sponge moistened with 0.4 or 0.8 mL of 100 µmol/L citicoline, or saline 0.4 mL in the control group, was applied. The fourth group of rats was sham-operated, ie the sciatic nerve was exposed with no crush. Functional assessments were performed 4 weeks after crush injury. von Frey filaments (100 g threshold) were used to assess neuropathic pain. In addition, the sciatic functional index and extensor postural thrust (EPT) tests were used to assess motoric function.

The crush/citicoline 0.4 mL group had a lower percentage of pain (23.53%, n=17) compared with the crush/saline group (53.33%, n=15, P<0.005). The crush/citicoline 0.4 mL group also showed better motoric recovery, as seen in stronger EPT results (P<0.001). However, the sciatic functional index analysis did not show significant differences between groups (P=0.35). The crush/citicoline 0.8 mL group showed a higher percentage of pain (66.67%, n=18) and less EPT recovery. These results may be explained by more severe nerve injury due to compression with a larger administered volume.

In situ administration of 0.4 mL of 100 µmol/L citicoline prevents the occurrence of neuropathic pain and induces motoric recovery, evaluated by EPT test, 4 weeks after sciatic nerve injury.

• nerve injury
• nerve regeneration
• neuropathic pain

Mesenchymal stem cells are posing as a promising character in the most recent therapeutic strategies and, since their discovery, extensive knowledge on their features and functions has been gained. In recent years, innovative sources have been disclosed in alternative to the bone marrow, conveying their associated ethical concerns and ease of harvest, such as the umbilical cord tissue and the dental pulp. These are also amenable of cryopreservation and thawing for desired purposes, in benefit of the donor itself or other patients in pressing need. These sources present promising possibilities in becoming useful cell sources for therapeutic applications in the forthcoming years. Effective and potential applications of these cellular-based strategies for the regeneration of peripheral nerve are overviewed, documenting recent advances and identified issues for this research area in the near future. Finally, besides the differentiation capacities attributed to mesenchymal stem cells, advances in the recognition of their effective mode of action in the regenerative theatre have led to a new area of interest: the mesenchymal stem cells' secretome. The paracrine modulatory pathway appears to be a major mechanism by which these are beneficial to nerve regeneration and comprehension on the specific growth factors, cytokine, and extracellular molecules secretion profiles is therefore of great interest.

• Hand tissue engineering
• biomaterial scaffolds
• clinical translation
• stem cells
• surface micro-/nano-structures

AIM: To study the therapeutic effect of three tube-guides with electrical conductivity associated to mesenchymal stem cells (MSCs) on neuro-muscular regeneration after neurotmesis.

METHODS: Rats with 10-mm gap nerve injury were tested using polyvinyl alcohol (PVA), PVA-carbon nanotubes (CNTs) and MSCs, and PVA-polypyrrole (PPy). The regenerated nerves and tibialis anterior muscles were processed for stereological studies after 20 wk. The functional recovery was assessed serially for gait biomechanical analysis, by extensor postural thrust, sciatic functional index and static sciatic functional index (SSI), and by withdrawal reflex latency (WRL). In vitro studies included cytocompatibility, flow cytometry, reverse transcriptase polymerase chain reaction and karyotype analysis of the MSCs. Histopathology of lung, liver, kidneys, and regional lymph nodes ensured the biomaterials biocompatibility.

RESULTS: SSI remained negative throughout and independently from treatment. Differences between treted groups in the severity of changes in WRL existed, showing a faster regeneration for PVA-CNTs-MSCs (P < 0.05). At toe-off, less acute ankle joint angles were seen for PVA-CNTs-MSCs group (P = 0.051) suggesting improved ankle muscles function during the push off phase of the gait cycle. In PVA-PPy and PVA-CNTs groups, there was a 25% and 42% increase of average fiber area and a 13% and 21% increase of the “minimal Feret’s diameter” respectively. Stereological analysis disclosed a significantly (P < 0.05) increased myelin thickness (M), ratio myelin thickness/axon diameter (M/d) and ratio axon diameter/fiber diameter (d/D; g-ratio) in PVA-CNT-MSCs group (P < 0.05).

CONCLUSION: Results revealed that treatment with MSCs and PVA-CNTs tube-guides induced better nerve fiber regeneration. Functional and kinematics analysis revealed positive synergistic effects brought by MSCs and PVA-CNTs. The PVA-CNTs and PVA-PPy are promising scaffolds with electric conductive properties, bio- and cytocompatible that might prevent the secondary neurogenic muscular atrophy by improving the reestablishment of the neuro-muscular junction.

• Nerve regeneration
• Neurotmesis
• Tube-guides
• Mesenchymal stem cells
• Carbon nanotubes
• Functional assessment
• Gait biomechanical analysis
• Histomorfometry
• Polyvinyl alcohol

Many studies have been dedicated to the development of scaffolds for improving post-traumatic nerve regeneration. The goal of this study was to assess the effect on nerve regeneration, associating a hybrid chitosan membrane with non-differentiated human mesenchymal stem cells isolated from Wharton's jelly of umbilical cord, in peripheral nerve reconstruction after crush injury. Chromosome analysis on human mesenchymal stem cell line from Wharton's jelly was carried out and no structural alterations were found in metaphase. Chitosan membranes were previously tested in vitro, to assess their ability in supporting human mesenchymal stem cell survival, expansion, and differentiation. For the in vivo testing, Sasco Sprague adult rats were divided in 4 groups of 6 or 7 animals each: Group 1, sciatic axonotmesis injury without any other intervention (Group 1-Crush); Group 2, the axonotmesis lesion of 3 mm was infiltrated with a suspension of 1 250–1 500 human mesenchymal stem cells (total volume of 50 μL) (Group 2-CrushCell); Group 3, axonotmesis lesion of 3 mm was enwrapped with a chitosan type III membrane covered with a monolayer of non-differentiated human mesenchymal stem cells (Group 3-CrushChitIIICell) and Group 4, axonotmesis lesion of 3 mm was enwrapped with a chitosan type III membrane (Group 4-CrushChitIII). Motor and sensory functional recovery was evaluated throughout a healing period of 12 weeks using sciatic functional index, static sciatic index, extensor postural thrust, and withdrawal reflex latency. Stereological analysis was carried out on regenerated nerve fibers. Results showed that infiltration of human mesenchymal stem cells, or the combination of chitosan membrane enwrapment and human mesenchymal stem cell enrichment after nerve crush injury provide a slight advantage to post-traumatic nerve regeneration. Results obtained with chitosan type III membrane alone confirmed that they significantly improve post-traumatic axonal regrowth and may represent a very promising clinical tool in peripheral nerve reconstructive surgery. Yet, umbilical cord human mesenchymal stem cells, that can be expanded in culture and induced to form several different types of cells, may prove, in future experiments, to be a new source of cells for cell therapy, including targets such as peripheral nerve and muscle.

• Wharton jelly
• axonotmesis
• biomaterials
• chitosan
• functional analysis
• karyotype analysis
• mesenchymal stem cells
• rat
• stem cells
• stereological analysis
• umbilical cord

The treatment of peripheral nerve injuries remains one of the greatest challenges of neurosurgery, as functional recover is rarely satisfactory in these patients. Recently, biodegradable nerve guides have shown great potential for enhancing nerve regeneration. A major advantage of these nerve guides is that no foreign material remains after the device has fulfilled its task, which spares a second surgical intervention. Recently, we studied peripheral nerve regeneration using chitosan-γ-glycidoxypropyltrimethoxysilane (chitosan-GPTMS) porous hybrid membranes. In our studies, these porous membranes significantly improved nerve fiber regeneration and functional recovery in rat models of axonotmetic and neurotmetic sciatic nerve injuries. In particular, the number of regenerated myelinated nerve fibers and myelin thickness were significantly higher in rat treated with chitosan porous hybrid membranes, whether or not they were used in combination with mesenchymal stem cells isolated from the Wharton's jelly of the umbilical cord. In this review, we describe our findings on the use of chitosan-GPTMS hybrids for nerve regeneration.

• Axonotmesis
• Biomaterials
• Functional assessment
• Mesenchymal stem cells
• Neurotmesis
• Peripheral nerve
• Stereology
• Umbilical cord
• Wharton’s jelly

Peripheral nerves have the intrinsic capacity of self-regeneration after traumatic injury but the extent of the regeneration is often very poor. Increasing evidence demonstrates that mesenchymal stem/stromal cells (MSCs) may play an important role in tissue regeneration through the secretion of soluble trophic factors that enhance and assist in repair by paracrine activation of surrounding cells. In the present study, the therapeutic value of a population of umbilical cord tissue-derived MSCs, obtained by a proprietary method (UCX^®), was evaluated on end-to-end rat sciatic nerve repair. Furthermore, in order to promote both, end-to-end nerve fiber contacts and MSC cell-cell interaction, as well as reduce the flush away effect of the cells after administration, a commercially available haemostatic sealant, Floseal^®, was used as vehicle. Both, functional and morphologic recoveries were evaluated along the healing period using extensor postural thrust (EPT), withdrawal reflex latency (WRL), ankle kinematics analysis, and either histological analysis or stereology, in the hyper-acute, acute and chronic phases of healing. The histological analysis of the hyper-acute and acute phase studies revealed that in the group treated with UCX^® alone the Wallerian degeneration was improved for the subsequent process of regeneration, the fiber organization was higher, and the extent of fibrosis was lower. The chronic phase experimental groups revealed that treatment with UCX^® induced an increased number of regenerated fibers and thickening of the myelin sheet. Kinematics analysis showed that the ankle joint angle determined for untreated animals was significantly different from any of the treated groups at the instant of initial contact (IC). At opposite toe off (OT) and heel rise (HR), differences were found between untreated animals and the groups treated with either uCx^® alone or UCX^® administered with Floseal^®. Overall, the UCX^® application presented positive effects in functional and morphologic recovery, in both the acute and chronic phases of the regeneration process. Kinematics analysis has revealed positive synergistic effects brought by Floseal^® as vehicle for MSCs.

• Wharton’s jelly
• functional assessment
• mesenchymal stem cells
• myelinization
• neurotmesis
• stereology

• electrospinning
• nerve guide
• peripheral nerve regeneration
• stem cells

• Animals
• Antigens, Nuclear/analysis
• Cell Differentiation
• Cell Line
• GAP-43 Protein/analysis
• Glial Fibrillary Acidic Protein/analysis
• Glycolysis
• Humans
• Magnetic Resonance Spectroscopy
• Membranes, Artificial
• Mesenchymal Stem Cell Transplantation
• Mesenchymal Stem Cells/cytology
• Motor Activity
• Myelin Sheath/metabolism
• Nerve Crush
• Nerve Regeneration
• Nerve Tissue Proteins/analysis
• Neuroglia/cytology
• Peripheral Nerve Injuries/therapy
• Polyesters/therapeutic use
• Rats
• Sciatic Nerve/chemistry
• Sciatic Nerve/physiology
• Sciatic Nerve/surgery
• Sensation
• Wharton Jelly/cytology

• Adult
• Aged
• Female
• Fracture Healing
• Humans
• Humeral Fractures/complications
• Humeral Fractures/epidemiology
• Male
• Microsurgery
• Middle Aged
• Prognosis
• Radial Nerve/injuries
• Radial Nerve/surgery
• Radial Neuropathy/diagnosis
• Radial Neuropathy/epidemiology
• Radial Neuropathy/etiology
• Radial Neuropathy/surgery
• Recovery of Function
• Retrospective Studies
• Tendon Transfer
• Time Factors
• Treatment Outcome
• Wounds and Injuries/complications
• Wounds and Injuries/diagnosis
• Wounds and Injuries/epidemiology
• Young Adult