Abstract:

Objective To explore the feasibility of modified technique for the keratin/silk fibroin compound biomaterial, identify physicochemical properties, and evaluate biological properties. Methods The keratin and silk fibroin were extracted from human hair and worm silk, respectively. The SDS-PAGE was adopted to determine the properties of those two proteins. Two proteins were mixed at different concentrations and different concentrations of gelatin were added. The tensile mechanical tests were used to detect the keratin/silk fibroin compound biomaterial and then the optimal combination of protein concentration and gelatine concentration was screened. Variations of the spatial structure of proteins were analyzed by the Fourier transform infrared spectroscopy (FTIR). The compound biomaterial was embedded beneath the rabbit skin to evaluate its biocompatibility and the cytotoxicity was detected by the MTT assay. Results The concentration and purity of keratin and silk fibroin met the requirements of subsequent tests after extraction and purification. Mechanical tests showed that best mechanical properties were achieved when the concentration of gelatin was 2% and the ratio of keratin and silk fibroin was 60∶40. Results of the FTIR indicated that the spatial structure of each protein of the compound biomaterial did not vary significantly. Tests of embedding the compound biomaterial beneath the rabbit skin showed that the biocompatibility and degradation rate of the compound biomaterial were ideal. Results of the MTT indicated that the compound biomaterial has no significant cytotoxicity. Conclusion The physicochemical properties of reported keratin/silk fibroin compound biomaterial can be improved by proper ratio of keratin and silk fibroin and proper concentration of gelatine, which is more suitable for subsequent fundamental researches and clinical applications of repair and reconstruction of tissue engineering.

Key words: tissue engineering, keratin, silk fibroin