Recent work using organo-selenium compounds has shown that when these compounds are attached to medical devices, bacterial attachment can be inhibited. The coating varies depending upon the device. With contact lenses, the organo-selenium compound is at- tached to groups on the surface of the contact lens by a covalent bond. In the case of cellulose/bandages, an organo-selenium polymer was coated on the bandage. The selenium compound forms covalent bonds within the polymer. In the case of intra-ocular lenses (IOL) the selenium was also attached to chemical residues on the surface of the lens. For the selenium coated contact lens and the bandage, it was found that the different materials were resistant to the attachment of both gram-negative and gram-positive bacteria. In some cases over 8 logs of inhibition was observed. It was also found that although the selenium coatings were able to inhibit the attachment of bacteria, in the case of the contact lenses, no effect was observed
on the underlying corneal epithelial cells. This was because the mechanism of the inhibition was due to the generation of superoxide radicals by the attached selenide residues. However, as seen with selenium coated IOLs, mammalian cell growth is inhibited on its surface since the cells must form intimate contact with the selenium.