Abstract

New amphiphilic triblock copolymers of poly(hexylene adipates) (PHA) and poly(ethylene glycol) (mPEG) having different hydrophobic/hydrophilic ratios were synthesized using a facile one-pot condensation reaction. Three samples of three different molecular weights were synthesized and characterized using different techniques. The synthesized copolymers were exploited to prepare core-shell nanoparticles with hydrophobic PHA and hydrophilic mPEG forming the core and shell, respectively. The drug loading efficiency and drug release properties of the mPEG-PHA-mPEG nanoparticles were investigated using 5-fluorouracil (5-FU) as a drug model. The drug loading efficacy of the nanoparticles was found to be dependent upon the polymer hydrophobicity. Drug release characteristics also depended on polymer hydrophobicity. The cytotoxicity of released 5-FU was monitoring as an antiproliferative agent against human liver cancer cell line (HEPG2) as well as antimicrobial against both gram positive and gram negative bacteria. Results of the in vitro cytotoxic activity of the released 5-FU showed a sustained antiproliferative potency against the tested human liver cancer cell line for 26 days. Besides, results of the antimicrobial study revealed that the most potent inhibitory activity was against S. aureus which shows hindrance zone of about 48 mm against the tested reference strain.

Key words: Block copolymers; nanoparticles; drug delivery; polyester; controlled release; antitumor drugs