Use of chitosan conduit combined with bone marrow mesenchymal stem cells for promoting peripheral nerve regeneration.

Many studies have been dedicated to the development of scaffolds for improving post-traumatic nerve regeneration. The goal of this study was to develop and test chitosan conduit to use in peripheral nerve reconstruction, either alone or combined with bone marrow mesenchymal stem cells (BMSCs). In this study, the roles of the degree of deacetylation (DD) and molecular weight of chitosan on some biological properties of chitosan films, including hydrophilicity, degradation and BMSCs affinity were investigated. The molecular weight of Chitosans used are 5 x 10(4) Da, 2 x 10(5) Da, 5 x 10(5) Da, 1 x 10(6) Da, the deacetylation degrees are 85, 95%, respectively. The affinity of eight kinds of Chitosans to the BMSCs was assessed by MTT assay, the contact angle and the degradation time of the materials in vivo were also measured. Chitosans with the molecular weight of 1 x 10(6) Da and DD of 95% can significantly promote the survival and outgrowth of cells, which have better hydrophilicity and can remain integrity even after 8 to 16 weeks, all of above meet the requirement of nerve engineering. The BMSCs we transplanted can differentiate into neural stem cells in vivo, and the materials we selected combined with BMSCs can bridge 8-mm-long neural gap better resulting from the differentiation effects of the BMSCs.