Reduction Of Biofilm In Chronic Wounds By Antibacterial Protease Combined With Silver Dressing

To evaluate the efficacy of antibacterial protease combined with silver dressing on biofilm reduction and healing in chronic wounds. A pilot, single-blinded randomized controlled trial was conducted. Fifty-six participants with chronic wounds were recruited and randomized (1:1) to the experiment group (antibacterial protease solution + silver dressing, AP) or a control group (0.9% normal saline + silver dressing, NS). The interventions were carried out once two days and the wounds were monitored for 28 days. The wound tissue samples were collected. The bacteria and extracellular polymeric substance in the biofilm of the wound tissues were pathologically checked by transmission electron microscope (TEM) and confocal laser scanning microscope (CLSM). The wound volume reduction rate, Pressure Ulcer Scale for Healing (PUSH) score, pH and temperature were measured. After treatment for 28 days, in the AP group, bacteria and extracellular polymeric substance in the biofilm of the wound tissues decreased more significantly than those in the NS group when observed by CLSM (P < 0.001). Furthermore, the AP group displayed more significant reduction in the wound volume reduction rate, Pressure Ulcer Scale for Healing Score (PUSH) and pH compared to the NS group (P = 0.030, 0.023, 0.015, respectively). There were no statistical differences in wound temperature between the groups (P = 0.422). The application of antibacterial protease combined with silver dressing showed higher efficacy of the biofilm reduction in chronic wounds.