Antimicrobial Efficacy of Impregnated Human Acellular Dermal Substitutes in Burn Wound Models

Burn wound infections remain a major clinical challenge due to delayed healing, scarring, and the risk of sepsis, especially when complicated by multidrug-resistant (MDR) Gram-negative pathogens and biofilm formation. Acellular dermal matrices (ADMs) are widely used in reconstructive and burn surgery, yet they lack intrinsic antimicrobial activity, necessitating their combination with topical agents. Background/Objectives: This study investigates the antimicrobial and cytocompatibility profiles of ADMs impregnated with various antimicrobial agents, using in vitro planktonic and biofilm burn wound models. While the incorporation of antimicrobials into scaffolds has been previously explored, this study is, to our knowledge, the first to directly compare seven clinically relevant antimicrobial agents after they were impregnated into an ADM in a standardized in vitro model. Methods: Seven topical antimicrobials were tested against MDR Pseudomonas aeruginosa and Acinetobacter baumannii from burn patients. Results: The ADM with 1% acetic acid (AA) showed superior antimicrobial activity, achieving > 7 log₁₀ reductions in planktonic assays and complete inhibition of P. aeruginosa biofilms. In NIH 3T3 fibroblast cytotoxicity assays, the 1% AA ADM maintained cell viability at control levels, indicating excellent biocompatibility. Compared with agents such as Betadine^®, Octenilin^®, and colistin, which showed cytotoxicity, and Prontosan^®, which showed low efficacy, 1% AA uniquely combined potent antibacterial effects with minimal toxicity. Conclusions: Among the seven antimicrobial agents impregnated into ADMs, 1% AA demonstrated a unique efficacy and safety profile, supporting its potential for clinical application in integrated wound dressings and implantable biomaterials for infection control in burn care.