Cytocompatibility of silkworm cocoon layer extracts

Recently silk polymer produced by Bombyx mori silkworm has been considered as biological macromolecules. Silk polymer was extracted in PBS solution at $37^{\circ}C$ for 72 h or $72^{\circ}C$ for 24 h. The effect of EtOH treatment on the cocoon extraction was also examined. The extraction yield of cocoon was less than 1 wt% regardless of extraction conditions. UV spectroscopy showed that the experimental extracts have absorption bands at 280 nm. There is no cytotoxicity effect on the mouse fibroblast L929 cell. The phenotype of L929 cell was not changed under the experimental conditions. The proliferation behavior of L929 cell was not affected by the addition of cocoon extract. Therefore, cocoon extract might be cytocompatible and can be used as promising biomaterials.