Comparison of Mechanical, Antibacterial and Morphological Properties of Silk Sutures Coated with Silver Nanoparticles and Aloe Vera Herbal Extract: An In-vitro Study

Abstract

Introduction: Surgical sutures play an important role in wound healing at surgical sites, which are susceptible to microbial infections. These sutures need to prevent bacterial adhesion and proliferation, particularly in areas exposed to oral fluids, to avoid contamination inside the wound. Antibiotic-coated sutures have shown effective antibacterial properties, and silver has emerged as a promising antimicrobial agent. Additionally, Aloe vera, a natural source of bioactive compounds, has been extensively studied for its antibacterial, antiviral, anti-tumour, and anti-inflammatory activities. Aim: To analyse the morphological, mechanical, and antibacterial properties of plain silk sutures compared to silk sutures coated with silver nanoparticles (AgNPs) and silk sutures coated with AgNPs and aloe vera extract. Materials and Methods: This in-vitro study was conducted in the White Lab of Saveetha Dental College and Hospital, Chennai, Tamil Nadu, India, over a one-month period from September 2022 to October 2022. The study included three groups, with three samples in each group. Group A consisted of plain silk sutures, Group B consisted of silk sutures coated with AgNPs, and Group C consisted of silk sutures coated with AgNPs and Aloe vera extract. Morphological and microanalytical characterisation was performed using Scanning Electron Microscopy (SEM) images and Energy-Dispersive X-ray Spectroscopy (EDS). Tensile strength was determined using straight-pull and knotpull tests, following the Instron® method, and knot efficiency. Antibacterial efficacy was evaluated using antimicrobial culture tests for the three groups. Statistical analysis was performed using the Shapiro-Wilk test to assess normality of continuous variables, followed by parametric tests of significance including paired t-tests and Analysis of Variance (ANOVA). Results: The tensile strength, as determined by the straight-pull test, knot-pull test, and knot efficiency, was highest in Group C, followed by Group B and Group A (statistically significant, p-value<0.001 for straight-pull test, 0.038 for knot-pull test, and 0.002 for knot efficiency). Group B exhibited the highest antibacterial efficacy, followed by Group C, while Group A showed no antibacterial efficacy (statistically significant, p-value<0.001). Conclusion: This present pilot study suggests that both AgNPcoated and Aloe vera-coated sutures hold promise in preventing Surgical Site Infections (SSI) and promoting wound healing.