Organo-selenium Coatings Inhibit Multiple Species Of Biofilm Formation On Different Types Of Ophthalmic Device Material

Abstract

Purpose: : Biofilm formation can be a problem for both solid and sponge type 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.

Methods: : Both sponge and solid Labtican brand scleral buckles were coated with organo-selenium coupled to a silyation reagent. Staphylococcus aureus and Klebsiella pneumoniae biofilm formation was monitored by a standard CFU assay while the Pseudomonas aeruginosa assay was monitored using a multi-cell flow-through continuous-culture system. One-ml aliquots of overnight cultures were injected upstream of the flow cell. After inoculation, flow was stopped for 1 h to allow the bacteria to attach to inner and outer surfaces of the catheter and then followed by continuous flow for 24 hours. The material was then examined using both by a confocal laser-scanning microscope and a scanning electron microscopy. Stability studies, were also carried out, by soaking in PBS at 67oC.

Results: : The selenium coating inhibited biofilm formation by all three bacterial untreated buckles by CFU assays, flow cell assays, and imaging.The buckle coatings were also shown to be fully active after soaking in PBS for 2 months.

Conclusions: : Selenium can be used to coat a silicone buckle, which is stable and inhibits biofilm formation for both gram negative and gram positive bacteria.

Keywords: retinal detachment • bacterial disease • inflammation