Inhibition of Biofilms on Tympanostomy Tubes

DESCRIPTION (provided by applicant): Bacterial biofilm formation on medical implants is a serious clinical problem. Biofilms can turn a simple implant into a serious complication. Recently we showed that the covalent attachment of micrograms of organo-selenium to the surface of an orthodontic device will inhibit the formation of a biofilm without harmful side-effects. This has recently (2009) led to FDA approval for selenium coated orthodontic devices that can be placed into children's mouths. These devices are now on the market. The use of selenium to block bacterial biofilms is based upon the unique ability of certain organo-selenium compounds to be covalently attached to a material and yet still retain their ability to catalytically generate superoxide radicals on the surface. However, due to the short half-life of superoxide radicals, there are no effects on cells near the device. This reaction continues for as long as selenium remains attached to the device. Tests show that the selenium coating is still fully active after 3 months of soaking at an elevated temperature. Selenium inhibits gram negative and gram positive pathogenic bacteria as well as Candida albicans. The current application is based upon our recent findings that specific organo- selenium compounds can be attached to silicone tympanostomy tubes resulting in the inhibition of biofilm formation in vitro. Thus, the following specific aims are proposed: 1. To develop a pilot scale method to coat tympanostomy tubes with organo-selenium and test the resulting product in vitro against isolates obtained from otitis media patients. 2. To develop and test selenium coated tympanostomy tubes in an animal model for their ability to inhibit biofilm formation and persistent otorrhea. . PUBLIC HEALTH RELEVANCE: While tympanostomy tubes are the gold standard for treatment of otitmis media and effusion, their occlusion rate is between 11 and 25%, and otorrhea occurs in 15-50% of tube inserted ears. It is felt that biofilms forming on the tube material is the main factor in the development of otorrhea and tube occlusion. Based upon our findings that a covalent selenium coating will block biofilm formation on tympanostomy tubes, we propose testing selenium-coated tympanostomy tubes for their ability to inhibit tube occlusion and otorrhea.