Dual therapeutic approach: Biodegradable nanofiber scaffolds of silk fibroin and collagen combined with silver and gold nanoparticles for enhanced bacterial infections treatment and accelerated wound healing

The development of novel multifunctional wound healing materials based on natural bioactives has garnered significant interest in recent years due to their ability to stimulate the healing process and alleviate problems associated with standard wound dressings. In the presented work, a bimetallic combination of silver (Ag) and gold (Au) nanoparticles incorporated into silk fibroin (SF) and collagen (CL) composite nanofiber (CNF) using the electrospinning technique. The physicochemical investigations confirmed the successful integration of Ag and Au nanoparticles sizes of approximately 6.76 nm and 9.75 nm, with an average nanofiber diameter of 189.46 +/- 108.73 nm. The evaluation of composite nanofiber treated in the in vitro antibacterial tests zone of inhibition value S. aureus (17 mm) and E. coli (18 mm). Additionally, we analyzed the cell proliferation study using NIH3T3 fibroblast cell line treated with the composite nanofiber material. The SF/CL/Ag - Au composite nanofiber exhibited the highest level of cell proliferation compared to other matrices. This increased cell proliferation offers significant advantages in wound healing applications. Furthermore, in vivo study on wound healing activity in Sprague-Dawley rats demonstrated a remarkable healing percentage of 98.85%. These findings collectively highlight the promising potential of the SF/CL/Ag - Au composite nanofiber in promoting accelerated wound healing. The composite nanofibers demonstrated remarkable hemocompatibility of erythrocyte lysis percentages varying between 1.5% and 3.9%. Besides, swelling tests revealed that the material can absorb exudates from wound sites, facilitating tissue regeneration and cell adhesion. Finally, this research highlights the potential of the SF/CL/Ag - Au composite nanofiber excellent antibacterial activity, highest biocompatibility, enhanced wound healing, and highly suitable for various biomedical applications.