Abstract
Purpose::
Bevacizumab has a strong effect on vascular endothelial cells reducing leakage into the surrounding tissue from newly grown vessels. The substance is a potent non-selective VEGF inhibitor that was found to be effective for the treatment of subretinal neovascular membranes less than two years ago. Side-effects directly related to the substance are minimal. In filtering glaucoma surgery, conjunctival fibroblasts and the development of new episcleral vessels play a major role in the post-operative wound healing process. With this series of cell culture experiments, we aimed to determine those concentrations of Bevacizumab that are safe for possible treatment of filtering blebs during or after surgery.
Methods::
Monolayer NIH 3T3 mouse fibroblasts were cultured in 96-well plates. Bevacizumab (25 mg/ml stock solution) was diluted in DMEM medium in a concentration range from 25 ug to 0.025 µg/µl and added to the wells. After 48 hours surviving cells were assessed with the vital stain crystal violet. The optical density values were read in an ELISA reader at 550 nm wavelength.
Results::
Bevacizumab caused a dose dependent suppression of the cell proliferation activity. After 48 hours exposition the LD 50 was reached by a concentration of 11.25 µg/µl Bevacizumab. No antiproliferative effect of Bevacizumab on NIH 3T3 mouse fibroblasts was observed when used at concentrations of 0.75 µg/µl or lower.
Conclusions::
Bevacizumab treatment did not inhibit proliferation of mouse fibroblasts when used at concentrations of 0.75 µg/µl or lower. At higher doses, Bevacizumab may be toxic to the fibroblasts. It is unclear whether the toxicity is caused by the active agent or by those substances which are always included in the vial by the manufacturer. These first experimental results show that high concentrations of Bevacizumab may have a direct toxic effect on conjunctival fibroblasts. Wound healing control with the use of Bevacizumab seems to be possible and will now have to be tested in animal models.
Keywords: cell survival • wound healing • conjunctiva