Antimicrobial Coatings to Reduce Hospital Infections

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 DESCRIPTION (provided by applicant): To combat Healthcare Associated Infection (HAI), which is now the 3rd leading cause of death in the U.S., TDA Research, Inc. proposes to develop new antimicrobial copper-alloy coatings for high-touch stainless-steel surfaces that may be responsible for 40% of all HAI. Low-cost, durable coatings will be scientifically designed for the catalytic production of hydroxyl radicals, *OH, which have the highest oxidation-reduction potential (2.76V) of any non-fluorinated species in water, surpassing that of all common disinfectants: ozone-2.076V, hydrogen peroxide-1.776V, hypochlorous acid-1.482V and chlorine dioxide-0.954V. The extreme oxidizing potential of hydroxyl radicals allows destruction of bacterial and fungal cell walls as well as spore and virus coatings. Copper provides a variety of other kill-mechanisms, including binding to microbial defensive enzymes including catalase. In moist environments, Cu1+ and Cu2+ ions diffuse and displace Na1+ and K1+ in cell- membrane ion channels, destroying their semi-permeable properties and causing microorganisms to rupture. Clinical trials unambiguously demonstrate that ~40% of Healthcare Acquired Infection in intensive-care units is eliminated by replacing only a few of the most frequently touched objects in patient rooms: bed side-rails, nurse call buttons, visitor-chair arm rests, over-bed tra tables and IV posts with pure copper. Further, the clinical data shows that copper retains antimicrobial activity in real-world hospital settings and is not deactivated by normal handling. Although proven extremely effective, replacing all hospital high-touch items with fixtures of solid copper is cost-prohibitive. Moreover, pure copper quickly corrodes and is too soft to resist abrasion. To address these issues, TDA Research, Inc. proposes to develop cost-effective methods to deposit thin films (~4µm thick) of copper alloys specifically onto existing stainless-steel surfaces that comprise roughly half of the high-touch surfaces prevalent in hospitals, but which possess little or no antimicrobial properties. The copper alloys will be developed for adhesion, resistance against corrosion and abrasion, ease of application, and will be doped to maximize the catalytic production of hydroxyl radicals. In Phase I, standard protocols required for the registration of anti-microbial copper under the Federal Insecticide, Fungicide and Rodenticide Act, will be followed explicitly. This involves testing of 1" x 1" coupons against the five pathogens: Staphylococcus aureus (American Type Culture Collection, ATCC 6538), a methicillin-resistant strain of S. aureus (ATCC 33592), pathogenic Escherichia coli O157:H7 (ATCC 35150), Enterobacter aerogenes (ATCC 13048) and Pseudomonas aeuginosa (ATCC 15442). As controls, uncoated stainless-steel, pure copper, and stainless-steel coated with pure copper will be tested. Phase I research will be considered a success if the microbial burden is reduced a minimum of 3log10 relative to uncoated samples as required by the standard protocol; simultaneously meeting ASTM Elcometer 107 scratch tests and a 5000-cycle Taber pumice/Cl1- corrosion/wear test (ASTM D-4060) to withstand an equivalent of 150,000 hand touches, while reducing costs.