Clinical infections in burn, trauma and surgical wounds represent a huge economic and health care burden. In the U.S., there is a 2-5% infection rate in surgical wounds and up to a 20% rate in burn wounds. The current standard of care is intensive and expensive, involving frequent topical application of antimicrobials (twice daily) with painful dressing changes. Expensive advanced dressings with antimicrobials impair wound healing by depositing toxic concentrations of antimicrobials (typically >100 ?g/cm2 of silver/day). When used with biologic dressings, these standards of care still result in up to 20% infection rate. There is a critical unmet need for formulations that provide: long-term release of antimicrobials without toxic build up in wounds;support broad therapeutic use of advanced dressings;and reduce frequent dressing changes. Successful completion of Phase 1 research at Imbed Biosciences has resulted in the invention and development of a unique silver wound dressing product concept based on Imbed's patent-pending nanofilm technology: dissolvable microfilm wound contact dressing with uniquely stabilized silver nanoparticles. A key feature of the microfilm dressing is that it contains a small quantity of silver that provides more intimate contact of active silver with the wound bed, which is less toxic to the wound and gentler to use. The microfilm dressing conforms to the micro-contours of the wound bed to provide 'localized'and 'long-term'release of active silver ions. Inexpensive fabrication and low cost of goods makes the microfilm dressing a cost-efficient alternative (>60% savings) to expensive silver dressings for use with moist and biologic wound dressings. Results of Phase I research demonstrated that the microfilm silver dressing (1) kills 4 log10 CFU of several bacterial species, including MRSA, (2) provides sustained release of bactericidal silver for at least 4 days, (3) does not show detectable in-vitro cytotoxicity or in-vivo systemic toxicity, (4) allows normal wound healing by re-epithelialization, and (5) significantly reduces microbial colonization and expedites wound closure under biosynthetic dressings in contaminated murine wounds. Comparison to other silver dressings showed that the microfilm dressing releases up to 100x less silver than most available dressings, provides equivalent or better antibacterial activity, an allows normal wound re-epithelialization unlike some silver dressings. Based on this promising data from Phase 1 research, and enthusiastic feedback from clinicians and potential commercial partners, Phase II research aims to further develop, optimize, and validate the Microfilm Silver Dressing product concept for high-throughput fabrication (Aim 1), broad-spectrum antimicrobial activity (Aim 2), biocompatibility (Aim 3), and porcine wound healing (Aim 4). We have assembled a team of material scientists, microbiologists, and veterinary and medical surgeons, with a history of successful collaboration. Completion of Phase II research will provide optimized design and data sets for microfilm dressings required for manufacturing scale-up and regulatory approval for human clinical trials.
Wound management presents a huge economic and healthcare burden in the U.S. The research described in this SBIR application will lead to the realization of a unique microfilm wound dressing that immobilize broad- spectrum antibacterial agents on the wound surface and prevent wound infections under primary and secondary wound dressing. The new microfilm dressing will reduce frequent application of topical antiseptics and use of antibiotics;minimize painful dressing changes and nurse time, and lower patient pain, medication costs and length of hospital stays.
