Antibacterial functionalization of nylon monofilament surgical sutures through in situ deposition of biogenic silver nanoparticles

Abstract

Antibacterial coating of nylon monofilament sutures presents difficulties unlike non-absorbable braided sutures due to the nature of nylon material and absence of interstices. To solve these problems, a new technique using in situ deposition of biogenic silver nanoparticles (AgNPs) has been developed to coat nylon surgical sutures. The effect of AgNPs deposition on the surface roughness was observed, with significant reduction in average roughness (9.41 ± 0.96 nm), compared with uncoated sutures (12.35 ± 0.20 nm) (P < 0.05). The ICP-OES analysis of coated sutures revealed total Ag+ concentration of 11.25 ± 0.14 μg/mL, with an AgNPs release of 11.25, 11.27, 19.94, and 24.03% at 1, 3, 5, and 7 days, respectively. The sutures demonstrated bactericidal effects on Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae) wound pathogens with more than 99.9% reduction. The coated sutures indicated stable antibacterial activity against representative Gram-positive and Gram-negative isolates after 12-week storage. Haemolytic evaluation of coated sutures showed less than 1% lysis of human erythrocytes. In addition, coated sutures inhibited lipopolysaccharide-induced nitric oxide generation by 15.46 μM reduction. Cytocompatibility test on L929 fibroblast cells revealed approximately 81% cell viability and promoted cell migration by 51% after 24 h treatment. The study revealed that in situ deposition of AgNPs on nylon monofilament sutures did not alter the mechanical properties of the sutures, but conferred antibacterial and wound healing properties.