In vitro biocompatibility of chitosan-based materials to primary culture of hippocampal neurons.

The natural biomaterial chitosan has been widely used as a promising nerve guidance conduit material for peripheral nerve repair. This study aimed to investigate in vitro biocompatibility of chitosan to primarily cultured hippocampal neurons, one type of central nervous system (CNS) cells. The substrate made up of chitosan fibers or membranes was found to support the survival and growth of the attached hippocampal neurons by using light and electron microscopy as well as immunocytochemistry for neurofilament 200, growth-associated protein-43, microtubule-associated protein 2, beta-tubulin III and synaptophysin. MTT assay indicated that the cell viability of hippocampal neurons in chitosan fiber or membrane extract was not significantly different from that in hydroxyapatite extract or plain neuronal medium, but significantly higher than that in organotin extract after culture for different times. Western analysis revealed that no significant difference in the protein level of growth-associated protein-43 and beta-tubulin III was detected between hippocampal neurons cultured in chitosan extract and in plain neuronal culture medium. The results collectively demonstrate that chitosan is biocompatible to primary culture of hippocampal neurons without cytotoxic effects on cell phenotype and functions, raising a potential possibility of using chitosan for CNS therapy.