Safety profile of bevacizumab on cultured human corneal cells

To study the corneal biocompatibility of bevacizumab on various cultured human corneal cells.

Cell cultures of corneal keratinocytes (CKs), corneal fibroblasts (CFs), and corneal endothelial cells (CECs) were harvested from human donor eyes and exposed to various concentrations of bevacizumab (0.25-5.0 mg/mL). Cell viability was assessed by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at days 1 and 4 after exposure. For cytotoxicity testing, confluent cells were cultured in serum-depleted medium, and the MTT test was performed after 24 hours of incubation. Expression of vascular endothelial growth factor (VEGF), VEGF receptors (VEGFR1 and VEGFR2), keratan sulphate (KS), and cytokeratin-3 (AE5) was studied by immunohistochemistry. Live/dead viability/cytotoxicity assay was performed and analyzed by fluorescence microscopy after 24 hours of incubation. Cell morphology was assessed with a phase-contrast microscope after 7 days of exposure with different concentrations of bevacizumab (0.25-5.0 mg/mL), and signs of cellular damage were assessed.

No cytotoxic effect of bevacizumab on CKs, CFs, and CECs could be observed when used at a concentration of 5.0 mg/mL or lower. Bevacizumab-treated cells showed no signs of cellular damage compared with the control. CKs, CFs, and CECs stained positively for VEGF, VEGFR1, and VEGFR2. CKs and CECs stained positively for AE5, whereas CFs were immunopositive for KS.

Bevacizumab is not toxic to corneal cells of human origin in vitro at doses usually used for treatment of corneal neovascularization, which is 20-fold higher than that used for intravitreal application.