The impact of wound infections on our healthcare system is enormous. Infections of the dermis, including burns, surgical-site infections and chronic wounds affect approximately 6.5 million people, cause over 200,000 deaths and cost over 50 billion of dollars in direct medical costs in the United States annually. In fact, chronically-infected diabetic foot ulcers are considered the most significant wound care problem in the world. One major reason that these infections are so difficult to treat is because bacteria develop ?biofilms? after they colonize wounds. A biofilm is a structure, made primarily of polysaccharides, that encases bacteria and protects them from the immune response and antimicrobials, making them up to 1,000 times less susceptible to killing. Unfortunately, conventional antibiotics are not effective against biofilms and few new agents are in the production pipeline. Therefore, it is of vital importance that we seek new strategies to address biofilm infections and increase our armamentarium of therapeutic agents. Glycoside hydrolases (GHs) are natural enzymes, produced by many organisms that hydrolyze the glycosidic linkages between two or more carbohydrates, such as those found in biofilms. We hypothesize that GHs can be formulated to breakdown biofilms in wounds, making bacteria more susceptible to killing by conventional antibiotics. Our preliminary data strongly support this hypothesis, demonstrating that GHs can effectively degrade biofilms and disperse bacterial cells, making them significantly more susceptible to antibiotics, both in vitro and in vivo. In this project we will use physiologically and clinically relevant in vitro and in vivo models to identify the best GH/antibiotic formulations that eradicate polymicrobial biofilms. Currently, there are no effective products on the market that effectively break down established biofilms in wounds. There are several agents that report to prevent biofilm formation in wounds, but few claim to be effective at removing mature biofilms. So while many agents have prophylactic activity, few are efficacious at treating established infections. Therefore, the development of an effective biofilm-degrading agent would be transformative for wound care. It is also unlikely that GHs pose significant risk, because their targets (glycosidic linkages) are not readily found in human tissue, and they have been used on humans previously for other applications without reported safety concerns.
The impact of wound infections on our healthcare system is enormous, affecting approximately 6.5 million people, causing over 200,000 deaths and costing over 50 billion of dollars in direct medical costs in the United States annually. One major reason that antibiotics are ineffective at clearing these infections is because bacteria develop ?biofilms? after they colonize wounds. In this project we will develop a multilayered dressing that delivers the sustained topical release of glycoside hydrolases, which breakdown biofilms, as a minimally-invasive treatment strategy to control and eradicate biofilm infections in wounds.
