Neural cell transplantation effects on sciatic nerve regeneration after standardized crush injury in the rat
The goal of the present study was to assess whether in vitro-differentiated N1E-115 cells supported by a collagen membrane would enhance rat sciatic nerve regeneration after a crush injury. To set up an appropriate experimental model for investigating the effects of neural cell transplantation, we have recently described the sequence of functional and morphologic changes occurring after a standardized sciatic nerve crush injury with a nonserrated clamp. Functional recovery was evaluated using the sciatic functional index, the static sciatic index, the extensor postural thrust, the withdrawal reflex latency, and ankle kinematics. In addition, histomorphometric analysis was carried out on regenerated nerve fibers by means of the 2D-disector method. Based on the results of the EPT and of some of the ankle locomotor kinematic parameters analyzed, the hypothesis that N1E-115 cells may enhance nerve regeneration is partially supported although histomorphometry disclosed no significant difference in nerve fiber regeneration between the different experimental groups. Therefore, results suggest that enrichment of equine type III collagen membrane with the N1E-115 cellular system in the rat sciatic nerve crush model may support recovery, at least in terms of motor function. The discrepancy between functional and morphological results also suggests that the combined use of functional and morphological analysis should be recommended for an overall assessment of recovery in nerve regeneration studies.
[Show abstract] [Hide abstract] ABSTRACT: 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.0Comments 0Citations
- "Within the nervous tissue, resident and blood borne cell populations act as bioactive molecules sources in response to injury . Hence, the association of neuro-or glial-derived cells that could act as regenerative triggers in the absence of the native population (i.e., in cases of nerve tissue section/loss, neurotmesis  ) or as additional boosters to the intrinsic ongoing regenerative process (when no gap exists and direct suture is feasible  or neural support structures are preserved, axonotmesis/crush injury) has also been explored. The main difficulty of using these tissue specific cellFigure 1: Entubulation or tubulization principle for bridging severe peripheral nerve injuries with loss of nerve tissue, preventing tension-free neurorrhaphy. "
[Show abstract] [Hide abstract] ABSTRACT: 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.0Comments 2Citations
- "The cellular system can be directly injected into the neural scaffold that has been interposed between the proximal and distal nerve stumps or around the crush injury (in neurotmetic and axonotmetic injuries, resp.). Alternatively , implantation can be achieved by preadding the cells to the neural scaffold via injection or coculture (in most of the cellular systems, it is allowed to form a monolayer), and then the biomaterial with the cellular system is implanted into the injured nerve4748495051. The N1E-115 cell line is a mouse neuroblastoma cell line that can undergo neuronal differentiation in response to dimethylsulfoxide, adenosine 3 í® í° ;5 í® í° -cyclic monophosphate, or serum withdrawal [51, 54]. "
[Show abstract] [Hide abstract] ABSTRACT: Mesenchymal stem cells (MSCs) from Wharton's jelly present high plasticity and low immunogenicity, turning them into a desirable form of cell therapy for the injured nervous system. Their isolation, expansion, and characterization have been performed from cryopreserved umbilical cord tissue. Great concern has been dedicated to the collection, preservation, and transport protocols of the umbilical cord after the parturition to the laboratory in order to obtain samples with higher number of viable MSCs without microbiological contamination. Different biomaterials like chitosan-silicate hybrid, collagen, PLGA90:10, poly(dl-lactide-ɛ-caprolactone), and poly(vinyl alcohol) loaded with electrical conductive materials, associated to MSCs have also been tested in the rat sciatic nerve in axonotmesis and neurotmesis lesions. The in vitro studies of the scaffolds included citocompatibility evaluation of the biomaterials used and cell characterization by imunocytochemistry, karyotype analysis, differentiation capacity into neuroglial-like cells, and flow cytometry. The regeneration process follow-up has been performed by functional analysis and the repaired nerves processed for stereological studies permitted the morphologic regeneration evaluation. The MSCs from Wharton's jelly delivered through tested biomaterials should be regarded a potentially valuable tool to improve clinical outcome especially after trauma to sensory nerves. In addition, these cells represent a noncontroversial source of primitive mesenchymal progenitor cells, which can be harvested after birth, cryogenically stored, thawed, and expanded for therapeutic uses. The importance of a longitudinal study concerning tissue engineering of the peripheral nerve, which includes a multidisciplinary team able to develop biomaterials associated to cell therapies, to perform preclinical trials concerning animal welfare and the appropriate animal model is here enhanced.0Comments 7Citations
- "The presence of transplanted N1E-115 cells in nerve scaffolds competing for the local blood supply of nutrients and oxygen and by space-occupying effect could have hindered the positive effect of local neurotrophic factor release leading a negative outcome on nerve regeneration. Thus, N1E-115 cells did not prove to be a suitable candidate cellular system for treatment of nerve injury after axonotmesis and neurotmesis and their application is limited only to research purposes as a basic scientific step for the development of other cell delivery systems, due to its neoplasic origin (Amado et al., 2010Amado et al., , 2008 Luis, Rodrigues, Geuna, Amado, Shirosaki, et al., 2008; Luis, Rodrigues, Geuna, Amado, Simoes, et al., 2008; Simoes et al., 2010). The MSCs isolated from the Wharton's jelly and delivered through PLC and chitosan type III membranes might be a potentially valuable tool to improve clinical outcome especially after trauma to sensory nerves, such as digital nerves. "