Abstract
Abstract: :
Purpose: Current treatments available for Proliferative vitreoretinopathy (PVR) have a modest benefit or are toxic in the therapeutic range. Blocking or modifying the action of de–differentiated Retinal Pigment Epithelial cells (RPE), responsible for PVR formation could enhance the overall prognosis of this condition. De–differentiated RPE cells as well as PVR membranes express a specific cell surface carbohydrate. A naturally occurring substance derived from the edible mushroom, the Agaricus Bisporus Lectin (ABL), binds specifically to this surface carbohydrate. The aim of the present study was the development of a precise targeted drug delivery system, specifically the conjugation of ABL with 5–Fluorouracil (5FU), in order to exclusively target and arrest the proliferation of the de–differentiated RPE cells as well as to decrease the cytotoxic effects on other cells that would occur if 5FU was applied independently. Methods: ABL and 5FU were conjugated through a series of chemical reactions. Different concentrations of the conjugated product (ABL and 5FU), non–conjugated ABL and 5FU alone were tested on ARPE19 cells. The exposure time was 30 minutes. The antiproliferative effect on days 1, 3, 7 and 14 was compared using A Non–Radioactive Cell proliferation assay. Controls consisted of the addition of Asialofetuin (ASF), a substance that blocks the action of ABL as well as untreated cells. Results: The proliferation assay showed a statistically significant antiproliferative effect of the conjugate(ABL+5FU) and the 5FU alone at the different time points when compared to the controls. The non–conjugated ABL showed no antiproliferative effect after 30 minutes of exposure. The addition of ASF to the conjugate blocked the antiproliferative effect, indicating that the action of the conjugate is due to the additive effect of ABL with 5FU and not of 5FU alone. Conclusions: The conjugation of ABL and 5FU is achievable through a series of complex chemical reactions. The Conjugate caused a statistically significant antiproliferative effect In Vitro. Future studies will evaluate the effects of the conjugate on other wound healing processes such as migration, adhesion and contraction.
Keywords: retinal detachment • proliferative vitreoretinopathy • vitreoretinal surgery