Fabrication and biocompatibility of neem/chitosan coated silk sutures for infection control and wound healing

The surgical site infections cost 0.5 % of the annual budget of the hospitals. Therefore, present research aimed to develop and evaluate antibacterial Neem/chitosan-coated silk braided sutures to reduce the risk of hospital-acquired surgical site infections. The silk braided sutures were coated by dip-coating technique by using 5, 10, 15 and 20 % concentrations of ethanolic Neem extract and chitosan. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and tensile strength measurements were used to examine the surface morphology, chemical composition, and tensile strength of the coated sutures. At a 20 % concentration, the sutures showed strong antibacterial action against Escherichia coli and Staphylococcus aureus, with inhibition zones of 15 and 19 mm, respectively. Additionally, the sutures demonstrated low cytotoxicity in the MTT assay, good radical scavenging activity, and hemolytic activity of less than 2 % at all concentrations. The sutures for the in vivo investigation were coated at a concentration of 20 % since this concentration showed the best antibacterial action. The rats were incised on both sides of their spine, with the left side stitched with uncoated sutures, and the right side stitched with coated sutures. The wound was inoculated with E. coli and S. aureus and examined for 7 days. The results indicated complete healing of the wound at the site where the coated sutures were applied. On other hand, wound with uncoated suture was still not completely healed and revealed signs of infection. The in vivo study revealed the efficacy of Neem/chitosan-coated sutures in wound healing and infection control.