Novel self-disinfecting surface

Abstract

The colonization of medical devices by micro-organisms is an ongoing problem, particularly as many strains of bacteria are becoming resistant to antibiotics. One method by which this could be addressed is the production of a surface that will kill bacteria on contact without releasing the disinfecting agent into solution. Self-disinfecting surfaces were prepared in which a quaternary ammonium salt was covalently bound onto a polyethylene film by a stable linkage. To achieve this, a low-density polyethylene film was treated with glow discharge followed by the graft polymerization of acrylic acid. The acid chloride derivative was then prepared. α,ω-Dibromoalkanes of various chain lengths were reacted with potassium phthalimide to form an N-alkylphthalimido group, and this was followed by an excess of piperidine to produce a tertiary amino group at the opposite end of the alkyl chain. The hydrolysis of the phthalimido group produced a primary amino function that was coupled to the grafted poly(acryl chloride). A reaction with octadecyl bromide resulted in the production of a quaternary ammonium salt. The amide linkage by which the quaternary ammonium salt was attached to the polymer was stable, and no release of the disinfecting moiety took place in solution. Soluble compounds containing a similar quaternary ammonium function were prepared through the reaction of the primary amine group with acetyl chloride rather than the polymeric acid chloride to form substituted N-acetamides. In a microbiological pilot study, both the polymer-bound and soluble quaternary ammonium salts were effective against suspensions of Staphylococcus aureus, Escherichia coli, and Saccharomyces cerevisiae. The results show that a self-disinfecting surface can be produced in which the quaternary ammonium function is an effective bacteriocide that remains bound to the polymer surface. In addition, the materials were toxic to a mammalian cell line (Chinese hamster ovary cells). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 381–389, 2006