Characterization of Bombyx mori and Antheraea pernyi silk fibroins and their blends as potential biomaterials

Fibroin proteins isolated from the cocoons of certain silk-producing insects have been widely investigated as biomaterials for tissue engineering applications. In this study, fibroins were isolated from cocoons of domesticated Bombyx mori (BM) and wild Antheraea pernyi (AP) silkworms following a degumming process. The object of this study was to obtain an assessment on certain properties of these fibroins in order that a concept might be had regarding the feasibility of using their blends as biomaterials. Membranes, 10-20 μm thick, which are water-insoluble, flexible and transparent, were prepared from pure fibroins and from their blends, and subjected to water vapor annealing in vacuum, with the aim of providing materials sufficiently strong for manipulation. The resulting materials were characterized by electrophoretic analysis and infrared spectrometry. The tensile properties of the membranes were measured and correlated with the results of infrared analysis. At low concentrations of any of the two fibroins, the mechanical characteristics of the membranes appeared to be adequate for surgical manipulation, as the modulus and strength surpassed those of BM silk fibroin alone. It was noticed that high concentrations of AP silk fibroin led to a significant reduction in the elasticity of membranes.