Alcon Inc.
CYTOTOXICITY TEST METHOD FOR MEDICAL DEVICE

Abstract:

A new two-layer modified agar overlay cytotoxicity method for medical device safety assessment are developed. The new two layer modified agar overlay cytotoxicity method has equivalent sensitivity, and greater efficiency compared to the ISO/USP direct contact and agar overlay assays. Assays were carried out in 6-well microplates. Nutrient agar medium with a 0.5% agar concentration was used to provide a base nutrient layer to support cell growth, L929 cells mixed nutrient agar (0.33% agar) were seeded on top of the base agar and cytotoxicity was evaluated after 24 hours per USP. Results demonstrated the two layer modified agar overlay cytotoxicity assay performs as well as the ISO/USP direct contact method with distinct advantages. Results showed that this two layer modified agar overlay method is more promising as compared to the traditional agar overlay and direct contact methods due to the diluted soft agar, avoided potential mechanical damage from test materials, and represents a valuable tool to evaluate medical device cytotoxicity.