Abstract
Purpose::
A drug delivery device that releases fluocinolone acetonide in the vitreous cavity (Retisert®, Bausch&Lomb) is currently used to treat posterior non-infectious uveitis.The purpose of this experiment is to evaluate the in vitro toxicity of fluocinolone Acetonide on retinal pigment epithelial (ARPE-19) and retinal neurosensory R28 cell lines
Methods::
ARPE-19 (ATCC, Manassas, VA) and R28 cells (courtesy of GM Seigel) were grown to reach 80% confluency in DMEM-F12 and DMEM high glucose media respectively.Fluocinolone acetonide,commercially available as a powder (Spectrum Chemical Mfg. Corp.Gardena CA), was solubilized in ethanol. The cells were treated with three different concentrations of the drug (1µg/ml, 10µg/ml and 100µg/ml). Cell viability was measured using the trypan blue dye exclusion assay at 2, 6 and 24 hours.
Results::
All concentrations of fluocinolone acetonide tested (1µg/ml, 10µg/ml, 100µg/ml) were found to be safe on the ARPE-19 cell line. The mean cell viabilities of ARPE-19 cells after 24 hours exposure to 1µg/ml ,10µg/ml and 100 µg/ml were 96.0% ±0.7% , 96.0% ±1.5% and, 97.2% ± 0.2% respectively compared to control untreated ARPE-19 cell (94.9% ± 1.3%p>0.05). A toxic effect was seen only at 24 hours for the highest concentration (100ug/ml) in the R28 cell line (51.0%± 10.4%). The mean cell viabilities of R28 cells at 1 and 10 µg/ml were 73.8%± 12.6% and 78.1%±3.0% respectively compared with control (80.8% ± 2.8%p>0.05).
Conclusions::
Fluocinolone acetonide is nontoxic to retinal pigment epithelial (ARPE-19) and neurosensory (R28) cells at the clinically used intravitreal dose observed with the Retisert® implant (0.1-0.2µg/ml).Toxicity was observed only at a concentration of 100µg/ml for R28 cells only, a 500- fold increase in the concentration released by the device.
Keywords: retinal pigment epithelium • drug toxicity/drug effects • retinal culture