Enhancement of nerve regeneration along a chitosan conduit combined with bone marrow mesenchymal stem cells

Many studies have been dedicated to the development of scaffolds for improving post-traumatic nerve regeneration with different biomaterials. Nerve autografting is the most common surgical procedure currently used to repair nerve defects as a gold standard. To address the disadvantages of limited availability of donor nerves and donor site morbidity, we have fabricated chitosan conduits and seeded them combined with bone marrow mesenchymal stem cells (BMSCs) as an alternative. The conduits were tested for efficacy in bridging the critical gap (8 mm) in sciatic nerves of adult rats, which including sciatic nerve function index (SFI), ethology observation, histologic detection, immunohistochemistry detection. The BMSCs were tested for survival rate and differentiation by fluorescence labeling. Six weeks after operation, the SFI, average regenerated fiber density, and fiber diameter in nerves bridged with BMSCs were similar to those treated with autograft, but significantly higher than those bridged with chitosan conduits only (P < 0.05) because of the differentiation of BMSCs. Evidence is thus provided to support the effect of using multi-channel chitosan conduits seeded with BMSCs to treat critical defects in peripheral nerves. This provides the basis to pursue chitosan and BMSCs combination is an effective method to improve the nerve healing, which may be used as an alternative to the conventional nerve autografts.