Cytotoxicity evaluation of toxic substances identified in recent reported toxic lots of perfluorocarbon liquids used in intraocular surgery in patients

Abstract

Purpose : Perfluorocarbon liquids (PFCL) are used in intraocular surgery and considered safe for many years, but after 2013 many episodes of acute eye toxicity are reported in several countries. The study proposes to evaluate cytotoxicity of toxic substances identified in recent reported toxic lots of perfluorocarbon liquids (medical device cytotoxicity test).

Methods : Retinal pigment epithelial cells (ARPE-19 cell line) were seeded at a cell density of 1 x 10⁴ per well and grown for one week in standard culture conditions. Following, cells were exposed for 1 hour directly to the already identified toxic substances (perfluorooctanoic acid (PFOA), dodecafluoro-1-heptanol (DFH) and tri-n-butyltin bromide (TBT-Br)) in different concentrations detected in chemical analysis. The concentrations were prepared by mixing with repeatedly checked non-cytotoxic PFO samples. Following cells were grown 24 hours and the MTT assay was performed to measure cell culture viability in each well. The experiments (n=9) were performed under GLP following ISO 10993-5:2009 norms and a recent new patented method for cytotoxicity testing of volatile medical devices.

Results : The cell culture viability reduced respectively to 0%, 1% and 1% on exposure of 0.02%, 0.05% and 0.1% PFOA concentrations, to 69% (69±18%), 0% and 0% on exposure of 0.1%, 1% and 10% DFH concentrations and to 3%, 3% and 2% on exposure of 600, 60 and 6 ppm TBT-Br concentrations. According to ISO norms, ≤ 70% cell cultures viability indicates presence of toxic substance. Cell culture exposed to cell culture medium and control non-cytotoxic PFO samples retained cell culture viability ≥ 70%.

Conclusions : Detection of PFOA, DFH and TBT-Br toxic effects in RPE cells confirms their roles in recent acute eye toxicity. Remarkably some of them are not related to incompletely fluorinated compounds. Cytotoxicity test method cannot be avoided for safety measurement of medical devices although it is applied best chemical analytical tests.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.