Comparison of Native and Regenerated Antheraea Pernyi Silk Fibroin

The regenerated Antheraea pernyi silk fibroin (RASF) was harvested by dissolving the silk fibers in a calcium nitrate solution. XRD result demonstrated that both native and regenerated Antheraea pernyi silk fibroin involved the α-helix conformation, and DTG curves showed that their thermal decompositions were quite similar and proceeded three steps. However, rheological measurements figured out that the molecule weight of RASF decreased from 246 kDa to 199 kDa, comparing with native Antheraea pernyi silk fibroin. Also, the tensile properties of the RASF film, which were the same to those of regenerated Bombyx mori silk fibroin film, were observed.

Mineralization of calcium phosphate induced by a silk fibroin film under different biological conditions

Silk fibroin films can have an important effect on the mineralization process of calcium phosphate in different biological environments. There was improvement of MSF with good biocompatibility that are promising in bone tissue engineering.

Click Decoration of Bombyx mori Silk Fibroin for Cell Adhesion Control

Silk fibroin produced by the domesticated silkworm, Bombyx mori, has been studied widely as a substrate for tissue engineering applications because of its mechanical robustness and biocompatibility. However, it is often difficult to precisely tune silk fibroin’s biological properties due to the lack of easy, reliable, and versatile methodologies for decorating it with functional molecules such as those of drugs, polymers, peptides, and enzymes necessary for specific applications. In this study we applied an azido-functionalized silk fibroin, AzidoSilk, produced by a state-of-the-art biotechnology, genetic code expansion, to produce silk fibroin decorated with cell-repellent polyethylene glycol (PEG) chains for controlling the cell adhesion property of silk fibroin film. Azido groups can act as selective handles for chemical reactions such as a strain-promoted azido-alkyne cycloaddition (SPAAC), known as a click chemistry reaction. We found that azido groups in AzidoSilk film were selectively decorated with PEG chains using SPAAC. The PEG-decorated film demonstrated decreased cell adhesion depending on the lengths of the PEG chains. Azido groups in AzidoSilk can be decomposed by UV irradiation. By partially decomposing azido groups in AzidoSilk film in a spatially controlled manner using photomasks, cells could be spatially arranged on the film. These results indicated that SPAAC could be an easy, reliable, and versatile methodology to produce silk fibroin substrates having adequate biological properties.