A Novel Silk Sericin/Poly (Vinyl Alcohol) Composite Film Crosslinked with Genipin: Fabrication and Characterization for Tissue Engineering Applications

Abstract

Silk sericin, a gumming protein from silk cocoons, has been a considerable natural protein-based biopolymer for fabrication of desired constructs for potential tissue engineering applications. This study investigated the formulation of a novel biopolymeric silk sericin/poly (vinyl alcohol) film with genipin as crosslinking agent and its physical properties. Silk sericin itself forms a fragile material, adding other polymers such as poly (vinyl alcohol) and glycerin, a plasticizer, resulting in a strong and flexible matrix. The results indicated that at higher concentration of genipin (0.1% w/v), the percentages of crosslinking in sericin/poly (vinyl alcohol) films was significantly higher. The matrices also exhibited higher tensile modulus value and higher elasticity at higher genipin concentration which can be inferred to higher integrity of the structure compared to matrices with genipin at low concentration (0.01% w/v). On the other hand, the reverse patterns were found in percentages of light transmission and the releasing profile of sericin from the composite films. Adding genipin into the matrices resulted in a lower percentage of light transmission indicated the increase in opacity. The releasing profile of sericin from the films showed that high genipin concentrations reduced the peak of protein released and trended to provide the sustain-released profile of protein. These findings indicated that silk sericin film can be formed and the concentrations of crosslinking agents really affect its physical properties.