Characterization of Transgenic Silkworm Yielded Biomaterials with Calcium-Binding Activity

Silk fibers have many inherent properties that are suitable for their use in biomaterials. In this study, the silk fibroin was genetically modified by including a Ca-binding sequence, [(AGSGAG)(6)ASEYDYDDDSDDDDEWD](2) from shell nacreous matrix protein. It can be produced as fibers by transgenic silkworm. The Ca-binding activity and mineralization of the transgenic silk fibroin were examined in vitro. The results showed that this transgenic silk fibroin had relatively higher Ca-binding activity than unmodified silk fibroin. The increased Ca-binding activity could promote the usage of silk fibroin as a biomaterial in the pharmaceutical industry. This study shows the possibility of using silk fibroin as a mineralization accelerating medical material by generating genetically modified transgenic silkworm.