Electrospun chitosan fibers for nerve regeneration

Abstract

Electrospinning of chitosan, a naturally-available polysaccharide obtained from N-deacetylation of chitin, to arrive at a nanofibrous scaffold for nerve tissue engineering, was investigated. The average diameter of chitosan nanofibers electrospun from 7% chitosan dissolved in 70:30 trifluoroacetic acid (TFA)/dichloromethane (DC) was 130+-10 mm. The as-spun chitosan nanofibrous matrix was neutralized to improve the physical integrity of the fibrous structure in a cell culture condition. Cytocompatibility, cell adhesion and cell proliferation on these as-spun mats were examined using the Schwann cell line RT4-D6P2T (SCs) and the mouse fibroblast cell line L929 as reference cells. Experimental results from MTT assay showed that the as-spun chitosan mats did not release substances detrimental to Schwann cells and mouse fibroblasts, and indicated much better for cell attachment due to its high surface area. However, the ability to promote the cell proliferation of fibrous scaffold was not observed when comparing with the film scaffold. Interestingly, from SEM images, Schwann cells exhibited a spindle-like shape when they were cultured on the flat substrate, while exhibited the expanded shape with discrete branches on their surface when they were seeded on the fibrous scaffold. This evidence indicated the influence of surface morphology of scaffolding materials on the cell behaviors.