A Preliminary Study on Spider Silk as Biomaterial for Peripheral Nerve Regeneration

Biomaterials for Tissue Engineering applications have to be biocompatible and biodegradable, they should enhance cell adhesion and enable sufficient nutrient transport. Moreover, in regard to nerve repair they have to provide high mechanical stability in addition to sufficient elasticity. Spider silk ought to combine all mentioned properties and, thus, is investigated in this study concerning its cytotoxicity, mechanical properties and applicability in cell culture. Experiments are performed with the established cell lines PC-12 cells and immortalized Schwann cells, often used for neurobiological and neurochemical studies and well described in the literature. Cells were cultured in the presence and on spider silk respectively. Cytotoxicity, viability (MTT-assay) and proliferation (BrdU-assay) of the cell lines growing on the spider silk strands were investigated. Additionally, morphology of cell settling and spreading of the cells on the strands were observed by means of confocal and SEM micrographs. Mechanical properties as mechanical strength and elasticity were evaluated subject to an increasing filament cross section. The results indicate the excellent suitability of spider silk for enhanced guided nerve repair.