Silver nanoparticle-coated suture effectively reduces inflammation and improves mechanical strength at intestinal anastomosis in mice

BackgroundOur previous studies have revealed that silver nanoparticles (AgNPs) had anti-inflammatory properties. In this study, we coated AgNPs onto the surface of absorbable suture, to further explore their anti-inflammatory efficacy and potential clinical application using an intestinal anastomosis model.MethodsLayer-by-layer deposition was used to coat AgNPs on absorbable sutures. Scanning electron microscopy (SEM) was conducted to observe the morphology and distribution of AgNPs on suture surface. 1 cm of either non-coated suture, suture coated with antibiotics or AgNPs-coated suture was placed on E. coli overlay of LB agar plates to test for bacterial inhibition. The respective sutures were then used for ileal anastomosis in mice. The anastomotic sites were harvested to investigate the degree of tissue inflammation and cell proliferation, as well as collagen deposition. Furthermore, burst pressure measurement was employed to test for mechanical properties.ResultsSEM observation indicated AgNPs could be immobilized and distributed on suture surface evenly. AgNPs-coated suture had the best in vitro anti-bacterial efficacy when compared with other groups. Subsequent immunohistochemistry in the intestinal anastomosis model showed significantly less inflammatory cell infiltration (macrophage and neutrophil) and better collagen deposition in the anastomotic tissue in the AgNPs-coated suture group. Burst pressure measurement in healed anastomosis further confirmed that AgNPs-coated suture had better mechanical properties.ConclusionOur study suggests that AgNPs-coated sutures can improve anastomosis healing due to better mechanical properties from reduced inflammation.