Fluorinated and pegylated polyaspartamide derivatives to increase solubility and efficacy of Flutamide

Abstract

New fluorinated amphiphilic copolymers based on a biocompatible polyaspartamide have been prepared in order to obtain polymeric micelles useful for delivering anticancer drugs. In particular, α,β-poly(N-2-hydroxyethyl)-d,laspartamide (PHEA) has been derivatized with polyethylene glycol (PEG2000) and ethylendiamine (EDA). Both these portions form the hydrophilic part of the copolymer, while the hydrophobic moiety is given by 1,2,4-oxadiazoles: 5-pentafluorophenyl-3-perfluoroheptyl-1,2,4-oxadiazole (PPOX) or 3-carboxyethyl-5-pentadecafluoroheptyl-1,2,4- oxadiazole (CPOX). Copolymers named PHEA-PEG2000-EDA-PPOX and PHEA-PEG2000-EDA-CPOX have been prepared with various degrees of derivatization and characterized by spectroscopic analyses. Size exclusion chromatography, pyrene colorimetric assay, light scattering analysis and scanning electron microscopy have evidenced the occurrence of a self-association process in aqueous medium. The ability of these aggregates to incorporate a hydrophobic drug and increase its solubility has been evaluated by using Flutamide, a fluorinated anticancer agent. Moreover, the activity of Flutamide-loaded micelles on proliferation of dihydrotestosterone stimulated LNCaP cells has been determined and compared to that of free drug.