654 Investigation of Germ Patency of a Polylactic Acid-based Membrane for the Treatment of Burns

Abstract Introduction Infections are a very serious complication during the treatment of burns. To avoid such infections, burn care dressings and skin substitutes should be impermeable to germs. Polylactic membranes (PLM) are based on polylactic acid (PLA) and as an elastic membrane it mimics the natural skin. They are indicated for superficial (2a°) and deep dermal/partial thickness (2b°) skin loss diseases like burns. While being permeable to oxygen and water vapor, they provide a physical barrier for microorganisms. The infection rate of the PLM in burns was about 2,9% on average and was published in 11 studies. The effectiveness of the physical barrier for microorganism was tested in an in-vitro model. Methods The sterile PLM samples were aseptically transferred into sterile petri dishes and inoculated with 100 µl each of a bacterial suspension. The test strains Staphylococcus aureus (ATCC 6538) with approximately 730 colony forming units (cfu) and Pseudomonas aeruginosa (ATCC 10145) with approximately 350 CFU / sample were used. The bacterial suspension was spread over the surface and dried. PLM were transferred to Tryptic Soy Agar (TSA) plates. The incubation was carried out in each case with 3 batches per test strain after 1 day and 3 days at 37°C. After incubation, the PLM samples were visually examined for microbial growth under the samples and photographically documented. A control group with inoculation of culture medium and covered with PLM was also tested. Results There was no growth of bacteria detectable after 1 day and after 3 days under the PLM indicating that the PLM is not permeable to germs. The control group resulted in growth of bacteria and colony forming units and thus confirms that test method works well. Conclusions PLM is an effective physical barrier for microorganisms as germs do not pass the PLM. Applicability of Research to Practice immediately.