Assessing the Antimicrobial Effect of Novel Polylactic-Acid Wound Closure Matrices

Introduction: Chronic wounds are a significant healthcare challenge, particularly for the elderly and those with underlying conditions. Up to 90% of wounds contain biofilm, ranging from local colonization to sub-clinical infection, which worsens patient outcomes, prolongs treatment, and increases costs. Minimizing a wound’s bioload is critical for proper management. Recently, polylactic acid (PLA) wound closure matrices* have shown success in treating complex wounds, with empirical data suggesting an antimicrobial effect. This study presents data on the antimicrobial properties of these devices.Methods:An in-vitro experiment using human viable skin involved inducing partial thickness burns and infecting samples with either MRSA Staphylococcus aureus or Pseudomonas aeruginosa. Samples were treated with PLA matrices, copper (Cu) dressings, or left untreated as a control. After three days, tissues were analyzed for bacterial count and cytokine profiling. Additionally, 20 patients with grade 2 Wagner diabetic foot ulcers were randomized to receive weekly applications of either PLA matrices or collagen dressings. Bacterial DNA was isolated and quantified from Levine swabs taken at baseline, 2, and 4 weeks to estimate the number of bacterial CFUs present in wounds.Results:In the in-vitro study, PLA matrices significantly reduced Pseudomonas bacterial counts, comparable to Cu dressings, but only Cu dressings significantly reduced MRSA counts. Cytokine profiling showed increased angiogenic factors in PLA-treated Pseudomonas-infected tissues and elevated tissue inhibitors of metalloproteinases (TIMPs), which are crucial for tissue repair. The in-vivo RCT showed a significant reduction in bacterial bioload in PLA-treated wounds after four weeks, compared to collagen dressings.Discussion: The in-vitro results indicate a potential antimicrobial effect of PLA matrices against Pseudomonas, a challenging bacterium in wound infections. The increase in angiogenic factors in PLA-treated infections is clinically significant, as infections typically hinder angiogenesis. The elevated TIMPs in PLA-treated wounds highlight the immunomodulatory effects of PLA, as these molecules are involved in tissue repair and regeneration. The in-vivo RCT results confirmed these effects in human wounds, with significant reductions in bacterial load after PLA treatment. Taken together, these findings suggest that PLA matrices can effectively reduce the bacterial load and prevent wound infections even in heavily contaminated wounds.References: