Resistance of acellular dermal matrix materials to microbial penetration.

IMPORTANCE Acellular dermal matrices have many current and potential applications, but their long-term safety has not been extensively studied. In particular, limited information exists regarding such materials' resistance to infection. OBJECTIVE To assess the resistance to microbial penetration of common acellular dermal matrix materials used in reconstruction after skin cancer excision, treatment of chronic ulcers and burns, breast reconstruction, hernia repairs, and other applications. DESIGN Comparative in vitro study of 4 commercially available dermal substitutes for their ability to act as barriers to penetration by common skin pathogens. SETTING University-based dermatology and plastic surgery departments and a hospital microbiology laboratory. MATERIALS Four commercially available dermal substitutes, including AlloDerm (LifeCell), FlexHD (Musculoskeletal Transplant Foundation), Strattice (LifeCell), and NeoForm (Mentor Corporation). INTERVENTION We tested the 4 dermal matrix materials with the following 4 organisms commonly implicated in wound infections: Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes, and Candida albicans. Each material was inoculated with the same concentration of each pathogen. MAIN OUTCOME MEASURE The number of bacterial colonies grown on blood agar plates. RESULTS AlloDerm and rehydrated FlexHD were found to be the best barriers to penetration by P. aeruginosa. AlloDerm, FlexHD, and Strattice also prevented penetration by S. aureus and S. pyogenes; NeoForm was less effective in withstanding these organisms. The results of this study were inconclusive with regard to C. albicans penetration. CONCLUSIONS AND RELEVANCE Three of the 4 commonly used acellular dermal matrix materials are resistant to in vitro penetration by S. aureus and S. pyogenes and partially resistant to P. aeruginosa. Resistance to fungal pathogens is uncertain. Antimicrobial differences across matrix materials may influence their selection for particular uses, such as treatment of refractory leg ulcers or reconstruction after skin cancer excision.