A NOVEL ANTIBIOFILM TECHNOLOGY FOR CONTACT-LENS SOLUTIONS

Purpose: Nonsteroidal anti-inflammatory drugs, including sodium salicy late, inhibit extracellular bacterial biofilm production. The authors studied the effect of the addition of sodium salicylate on bacterial a dherence and biofilm formation on contact lenses and cases and commonl y used medical polymers. Methods: The study was done in vitro with bac terial adherence and biofilm measured on lenses and cases that were ex posed to saline contaminated with Staphylococcus epidermidis and Pseud omonas aeruginosa with and without 1 and 3 mm sodium salicylate. Bacte rial adherence to contact lenses was quantitated by a vortex assay and by scanning electron microscopy. Biofilm formation on contact lens ca ses and other polymers was measured by an optical density assay and a radiolabeling assay. Results: Inhibition of biofilm formation was demo nstrated on plastic contact lens cases in a dose-related manner with 1 and 3 mm sodium salicylate. A dose-related decrease in bacterial adhe rence also was noted. Assays with contact lenses also demonstrated les s adherence in the presence of sodium salicylate. Electron micrographs of the contact lens showed less biofilm, most noticeable with 3 mm sa licylate. Other studies demonstrated decreased adherence of S. epiderm idis to polyethylene and polystyrene. Sodium salicylate also decreased biofilm on plastic tissue culture wells, but sorbic acid paradoxicall y increased deposition. Conclusion: The authors found that the additio n of low-dose sodium salicylate to saline decreased the adherence of S . epidermidis and P. aeruginosa to contact lenses and lens cases. Biof ilm production also was decreased on the lens cases and on medical pol ymers used to make plastic cases. These studies suggest that sodium sa licylate deserves additional study to determine its use in contact len s solutions.