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Laboratory Research
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Biocompatibility and antimicrobial properties of a silver polyurethane foam dressing designed for use with negative pressure wound therapy Archel Ambosio, PhD, Devin Ginther An antimicrobial silver polyurethane foam dressing* was specifically engineered for use with the Vacuum Assisted Closure System¨ V.A.C.¨ Systemª with the goal of combining the clinical benefits of Negative Pressure Wound Therapy (NPWT) and the antimicrobial properties of silver. In designing the dressing, it was important that the dressing demonstrated efficacy against clinically relevant pathogens while still maintaining biocompatibility. The antimicrobial property of the silver foam dressing was first evaluated against various microbial organisms using the zone of inhibition test. Once the efficacy of the silver foam dressing against these organisms was established, an antimicrobial test based on ASTM E2149 was performed to quantify this efficacy. Briefly, the silver foam dressing was immersed in a solution previously inoculated with the challenge organism at a concentration of 105 CFU/mL. At 0.5, 1, 2, 6, 24, 48 and 72 hours, the concentration of surviving organisms was determined. To evaluate the safety profile of the dressing, biocompatibility testing was performed following ISO 10993 guidelines. Specifically, the following tests were carried out: MEM endpoint dilution cytotoxicity test, Acute Systemic Injection test, Guinea Pig Maximization Sensitization test and Intracutaneous Reactivity test. The results demonstrated that the silver foam dressing was effective against gram-positive and gram-negative bacteria, antibiotic-resistant bacteria such as MRSA and VRE, as well as fungal organisms, with microbial reduction of 99.9% per organism after only 30 minutes of contact. Additionally, a battery of ISO 10993 tests established the biocompatibility of the dressing. *V.A.C. GranuFoam Silver Dressing and V.A.C. System are registered trademarks of KCI Inc., San Antonio, TX |
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