Antibacterial-coated silk surgical sutures by ex situ deposition of silver nanoparticles synthesized with Eucalyptus camaldulensis eradicates infections

Surgical site infection arising from microbial contamination of surgical wounds is a major cause of surgical complications and prolong hospital stay. In this study, silver nanoparticles (AgNPs) biosynthesized using Eucalyptus camaldulensis extract were deposited on silk surgical sutures by ex situ method. Adherence of AgNPs to the surface of sutures was observed, with significantly reduced surface roughness (323.7 +/- 16.64 nm), compared with uncoated sutures (469.3 +/- 7.31 nm) (P<.001). Elasticity of AgNPs-coated (13 +/- 1.485%) and uncoated (8 +/- 0.728%) sutures was also significantly different (P<.05). Quantification of AgNPs demonstrated release of 3.88, 5.33, 5.44, 6.14% on day 1, 3, 5, 7, respectively from total Ag+ concentration (6.14 +/- 0.14 mu g/mL). The coated sutures produced a strong bacteriostatic effect on Staphylococcus aureus, an important wound pathogen with approximately 99% reduction in growth. In contrast, bactericidal effects were observed with Gram-negative pathogens including Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Cytocompatibility tested on human keratinocyte cells exhibited approximately 80% cell viability. The coated sutures revealed stable antibacterial properties up to 12 weeks. This work suggested the potency of AgNPs-coated sutures as a suitable biocompatible medical device for the management of surgical site infections.