An Intact Ex Vivo Pigskin Model for Evaluating Topical Treatments for Blepharitis‐Associated Biofilms

Importance Blepharitis is a chronic inflammatory condition of the eyelid margin that impacts millions of adults and children. Its etiology is unclear, and its treatment remains unsatisfactory. Objective To develop an intact ex vivo pigskin model to evaluate the etiology of and to determine effective treatments for blepharitis. Design Mature bacterial biofilms of Staphylococcus epidermidis were generated on intact pigskin explants. These biofilms were treated topically for 24 h before quantifying the residual biofilm bacteria. Results The amount of total bacteria after treatment with phosphate buffered saline (PBS) was 7.29 log. Using common clinical treatments, the amount of bacteria was 5.05 log for 10 % povidone iodine ( p < 0.05) and 4.96 log for 0.01% HOCl ( p < 0.05). The amount of bacteria for gentamicin treatment was 6.38 log, which was not significant from phosphate buffered saline (PBS) treatment ( p = NS). Using a prototype formulation, the level of bacteria was reduced to a non detectable level which was significantly lower than all other treatments ( p < 0.05). Conclusions and Relevance A model for studying bacterial biofilms on intact ex vivo pigskin explants was developed. Using this model, it was shown that a prototype formulation containing naturally derived antimicrobials and a biofilm disrupter was superior to several commonly used clinical treatments in eliminating biofilm bacteria. We believe this effective, antibiofilm formulation can be used safely in the eye for clinical applications.