Preparation of Thai silk fibroin/gelatin electrospun fiber mats for controlled release applications.

This work studied the effect of preparation conditions for electrospun fiber mats of Thai silk fibroin/type B gelatin (SF/GB) for controlled release applications. The increasing in applied voltage resulted in decreased average fiber size and narrow fiber size distribution. An increasing in silk fibroin content in blended solution resulted in larger size of the obtained electrospun fibers. Smooth fibers could be produced from SF/GB blended solution at weight blending ratios of 10/90, 20/80, 30/70, 40/60 and 50/50. The results on in vitro biodegradation test showed that SF/GB 10/90 electrospun fiber mat was rapidly degraded in collagenase solution due to direct biodegradation of gelatin by collagenase. From in vitro controlled release of two active agents (azo-casein and methylene blue) from SF/GB blended fiber mats, it was suggested that methylene blue could be adsorbed on the blended fiber mats, possibly due to attractive interaction of the positively charged molecules of methylene blue and negatively charged SF/GB fiber mats. In contrast, the same charge of blended fiber mats and azo-casein would result in the repulsive force, resulting in continuous diffusion of azo-casein from blended fiber mats within 72 h. The results indicated that SF/GB electrospun fiber mats had a high potential to be applied in controlled release applications.