Chitosan coated silk fibroin surface modified by atmospheric dielectric-barrier discharge (DBD) plasma: a mechanically robust drug release system.

The current study is designed to develop mechanically strong chitosan (Cs) coated silk based drug delivery system loaded with amoxicillin trihydrate (AMOX). For this purpose, surface modification of Antherarea assama silk fibroin (AASF) yarn is carried out using dielectric barrier discharge (DBD) oxygen (O2 ) plasma at atmospheric pressure followed by coating with drug incorporated Cs (AASF/O2 /Cs-AMOX). It is observed that O2 plasma treatment results in altering surface chemistry and morphology of silk fibroin surface which subsequently improves mechanical properties of AASF/O2 /Cs-AMOX yarn.  The AASF/O2 /Cs-AMOX yarn exhibits strong antibacterial activities against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria. In vitro drug release profile reveals biphasic release behavior of AASF/O2 /Cs-AMOX yarn consisting of immediate followed by controlled and sustained release of AMOX up to the observation period of 168 hours. MTT cell viability study further reveals that O2 plasma treatment and incorporation of AMOX do not have any adverse effect on cytocompatibility of AASF/O2 /Cs-AMOX yarn. Together, all these results suggest that AASF/O2 /Cs-AMOX yarn can be explored in treatment of bacterial infected wounds as potential surgical suture.