Controlled antibiotic-releasing Antheraea assama silk fibroin suture for infection prevention and fast wound healing

Background. The quest for developing silk fibroin as a biomaterial for drug release systems continues to draw research interest owing to its impressive mechanical properties as well as biocompatibility and biodegradability. The aim of this study is to develop low-temperature O-2 plasma-treated muga (Antheraea assama) silk fibroin (AASF) yarn impregnated with amoxicillin trihydrate as controlled antibiotic-releasing suture (AASF/O-2/AMOX) for preventing postoperative site bacterial infection and fast wound healing Methods. In this experimental study, AASF and AASF/O-2/AMOX sutures are used to close the surgical wounds of adult male Wistar rats of 4 months old and weighing 200-230 g. Results. Surface hydrophilicity induced by O-2 plasma results in an increase in drug-impregnation efficiency of AASF/O-2 yarn by 16.7%. In vitro drug release profiles show continuous and prolonged release of AMOX from AASF/O-2/AMOX yarn up to 336 hours. In vitro hemolysis assay reveals that O-2 plasma treatment and subsequent impregnation of AMOX do not affect the heertetmocompatibility of AASF yarn. The AASF/O-2/AMOX yarn proves to be effective for in vitro growth inhibition of Staphylococcus aureus and Escherichia coli, whereas AASF offers no antibacterial activity against both types of bacteria. In vivo histopathology studies and colony-forming unit count data revealed accelerated wound healing activity of AASF/O-2/AMOX over AASF yarn through rapid synthesis and proliferation of collagen, hair follicle, and connective tissues. Conclusion. Outcomes of this work clearly demonstrate the potential use of AASF/O-2/AMOX yarn as a controlled antibiotic-releasing suture biomaterial for superficial surgical applications.