Silk fibroin films for potential applications in controlled release

Silk fibroin extracted from Bombyx mori cocoon was processed into regenerated films and examined for potential application in controlled drug release. Instead of using dialysis process, the present study proposed a novel convenient method to remove LiBr from fibroin aqueous solution during film preparation process. The prepared fibroin films were characterized by FTIR and SEM, showing that the films were dense, homogeneous, and partially crystalized. The biocompatibility of fibroin films was initially evaluated by the adsorption of BSA. It was shown that at 10 mg/mL of BSA concentration, the BSA sorption reached 0.045 mg/cm2, which is indicative of good blood compatibility and biocompatibility of the fibroin. Further, the permeability and diffusivity of four model drugs in the fibroin films were investigated, and they were found to be on the same orders of magnitudes as many other controlled release materials, indicating that the naturally occurring fibroin is a good candidate material for uses in controlled release. The mass transport through the fibroin film pertaining to controlled drug release was also studied.