The Use Of A Covalent Selenium Coating To Inhibit Biofilm Formation On A Silicone Scleral Buckle

Abstract

Purpose: : Scleral Buckles are used to repair retinal detachments. Biofilm formation can be a problem for scleral buckles. This can lead to complications that can require the removal of the buckle, which may result in vision loss due to related ocular morbidity, primarily infection or recurrent retinal detachment. This study is a determination of the ability of a covalent selenium coating to inhibit biofilm formation on a scleral buckle. This is based upon the ability of selenium to catalyze the formation of superoxide radicals which kill bacteria that try to attach to the surface.

Methods: : Labtican brand 4050 silicone band style buckles were coated by coupling organo-selenium to a silylation reagent attached to the silicone. Unreacted material was removed by washing and the buckle was then sterilized with ethylene oxide. After sterilization the buckle was placed in a TSB media with 30-50 Staphylococcus aureus bacteria and allowed to set for 16 hours at 37 degrees C. The buckle was then removed and rinsed to remove any loosely attached bacteria. The buckle was then sonicated and the bacteria counted by a standard colony forming unit assay. All experiments were done in quadruplicate in two separate experiments.

Results: : It was found that the selenium coating showed complete inhibition of bacterial attachment to the buckle while the control untreated buckles contained over 6.7 logs of bacteria by two different attachment procedures. In imaging studies it was also found that little or no bacteria were seen on the treated buckles.

Conclusions: : A selenium coating on the silicone scleral buckles proved effective against the binding of S. aureus. No bacteria were found on the treated buckles while over 6 logs of bacteria were found on the controls.

Keywords: retina • sclera • microbial pathogenesis: experimental studies