Investigation on biocompatibility of silicone oil with retinal pigment epithelial cells and fibroblasts

Abstract

Purpose: In complex retinal detachment, silicone oil is often utilized as tamponade agent to provide long-term support to the retina. However, high specific gravity and emulsification affect the retinal tolerance to silicone oil. Previous studies have shown that high specific gravity may cause retinal damage while emulsification causes inflammation, glaucoma and peri-oil proliferation. This study aims to investigate the effects and biocompatibility of Densiron 68, a heavy silicone oil with high specific gravity and Siluron 2000, a novel emulsification-resistant silicone oil on human retinal pigment epithelial cells and mouse fibroblasts in vitro. Methods: ARPE-19 or L-929 cells were grown in Transwell® inserts and were treated with HBSS as control, Siluron 2000 or different amount of Densiron 68 for 3 or 7 days. Cytotoxicity on ARPE-19 and L-929 cells was assessed by CellTiter 96® AQueous Non-Radioactive Cell Proliferation Assay (MTS/PMS). Apoptosis was detected using TUNEL assay. The expressions of ARPE-19 cell marker, CRALBP and tight junction proteins, occludin and ZO-1, were determined by Western blot. Results: After a 3-day treatment with Densiron 68, no significant cytotoxic effects were observed in ARPE-19 and L-929 cells. However, treatment with Densiron 68 for 7 days caused marginal effect on cell survival. Preliminary data showed that there were more TUNEL positive nuclei and decreased tight junction protein expression in ARPE-19 cells. On the other hand, Siluron 2000 treatment caused no obvious cytotoxic effects in ARPE-19 and L-929 cells and no significant changes in the expressions of CRALBP, occludin and ZO-1 in ARPE-19 cells. Conclusions: This study helps to provide information on the possible undesirable effects of silicone oil. Our results suggest that Densiron 68 may induce adverse effects on ARPE-19 cells while Siluron 2000 is biocompatible with both ARPE-19 and L-929 cells in vitro.