There is a fast growing need for antimicrobial paints and coatings to improve microbial quality in residential, commercial, institutional, and industrial applications so as to control the growth of mold and/or reduce the risk of healthcare-associated infections or community-acquired infections. A number of paint products on the market claim """"""""antimicrobial"""""""" functions. However, the current products have significant shortfalls, including weak antimicrobial activities, risk of microbial resistance, and difficulty in monitoring and extending the antimicrobial functions once the paints are applied. To solve these problems, in this proposed project, we will use polymeric N-halamines, a class of widely used water and food disinfectants, as antimicrobial additives to provide biocidal effects against bacteria (including drug-resistant species), mold and other fungi species, viruses, and spores. An N-halamine is a compound containing one or more nitrogen-halogen covalent bonds. N-halamines have similar antimicrobial efficacy as hypochlorite bleach, but they are much more stable, none corrosive, with no reported cases of microbial resistance, and have a much less tendency to generate halogenated hydrocarbons. In our technology, a new N-halamine monomer developed in our lab, N-chloro-2,2,6,6- tetramethyl-4-piperidinyl acrylate (Cl-TMPA), will be polymerized to produce polymeric N-halamine latex emulsions. On adding a small amount of such emulsions into conventional water-based latex paint, the new paint will be able to provide potent antimicrobial activities against various microorganisms. The antimicrobial activity is anticipated to last for the lifetime of the paint under normal use. Challenging conditions (e.g., heavy soil, flooding, etc.) may consume more chlorine and thus shorten the antimicrobial duration. Nevertheless, the antimicrobial function of the new paints can be easily monitored by a simple potassium iodine/starch test. That is, polymeric N-halmines will react with potassium iodine to generate a dark blue color with starch. Thus, this test determines whether the paint still provides antimicrobial functions. If it shows that the antimicrobial function is lost, the polymeric N-halamine structures can be resumed by wiping the surface with diluted hypochlorite bleach to recharge the lost chlorine and regenerate the antimicrobial functions. The recharging can be repeated as needed. If successful, this technology will provide an innovative approach to protect high-touch, high-risk surfaces in a wide range of applications, which will have a broad and significant impact on health. This STTR Phase I study is designed to establish the feasibility and effectiveness of the new approach before continuation and expansion of the project.
The specific aims of the proposed research are to: (1) create polymeric N-halamine latex emulsions;(2) mix the polymeric N-halamine latex emulsions with commercially important latex paints, and characterize the physical properties, antimicrobial performance, and biocompatibility of the new paints developed;and (3) preliminarily determine the cost of the new approach.
The unique features of the new paints include the broad antimicrobial spectrum against bacteria, mold and other fungi species, viruses, and spores, the ease in monitoring the antimicrobial activity, the rechargability of N-halamines if the antimicrobial function is accidentally lost, and the low risk of microbial resistance. These advantages make the new polymeric N-halamine-based antimicrobial paints an attractive candidate for protecting high-touch, high-risk surfaces in residential, commercial, institutional, industrial, and other related facilities. This STTR Phase I research will serve as the foundation for continuation and expansion of the project and finally commercialize the products to improve the microbial quality of a wide range of environmental surfaces, and this will have a broad and significant impact on health.
