Surface modification of electrospun silk/AMOX/PVA nanofibers by dielectric barrier discharge plasma: physiochemical properties, drug delivery and in-vitro biocompatibility

The naturally obtained protein Bombyxmori silk is a biocompatible polymer with excellent mechanical properties and have the potential in controlled drug delivery applications. In this work, we have demonstrated dielectric barrier discharge (DBD) oxygen (O-2) plasma surface modified electrospun Bombyxmori silk/Amoxicillin hydrochloride trihydrate (AMOX)/polyvinyl alcohol (PVA) nanofibers for drug release applications with controlled plasma treatment duration (1-10 min). The findings indicate that plasma treated electrospun nanofibers for 1-3 min exhibited significant enhancement in tensile strength, Young's modulus, wettability and surface energy. The plasma treated electrospun nanofibers for 1-5 min showed remarkable increase in AMOX released rate, whereas the electrospun nanofibers treated with plasma irradiation beyond 5 min showed only marginal increase. Moreover, the plasma treated nanofibers also exhibited good antibacterial activity against both E. coli (gram negative) and S. aureus (gram positive) bacteria. The untreated and the plasma treated silk/AMOX/PVA electrospun nanofibers for 1-3 min showed enhanced viability of primary adipose derived mesenchymal stem cells (ADMSCs) growth on them and much less hemolysis activity (< 5%). The in vitro biocompatibility of various electrospun nanofibers were further corroborated by live/dead imaging and cytoskeletal architecture assessment demonstrating enhanced cell adhesion and spreading on the plasma treated nanofibers for 1-3 min. The findings of the present study suggest that the silk/AMOX/PVA electrospun nanofibers with plasma treatment (1-3 min) due to their enhanced drug release ability and biocompatibility can be used as potential wound dressing applications. [GRAPHICS] . Effect of O-2 DBD plasma treatment time on the surface properties of silk/AMOX/PVA nanofibers. Plasma treatment time of 1 min shows the highest rate of surface modifications in terms of chemical, mechanical, wettability and surface energy improvement. Increase in plasma treatment time up to 5 min results in continuous increasing drug release rate. The plasma treatment time does not cause any hemolytic effect, also improved cell viability and cell attachment with cell spreading is observed after 1-3 min of plasma treatment time.