Cytotoxic Activity and Kinetic Release Study of Lovastatin-Loaded Ph-Sensitive Polymersomes

Abstract

Triblock poly(ε-caprolactone) – poly(ethylene glycol) – poly(ε-caprolactone) (PCL-PEG-PCL) copolymers were synthesized and used to prepare polymersomes for controlled release of lovastatin (LOV) as hydrophobic drug. Biodegradable PCL-PEG-PCL copolymer nanoparticles were prepared and the drug loading, release, release kinetics, and anti-cancer activity of these drugs was investigated. The PCL-PEG-PCL copolymer was synthesized by ring-opening polymerization of e-caprolactone in the presence of mPEG as the initiator and Sn(Oct)₂ as the catalyst. The synthesized copolymers and nanoparticles were characterized by FTIR, ¹H NMR, DLS, and AFM techniques. The efficiency of drug loading and release from nanoparticles in vitro was studied by UV-Vis spectrophotometry. Additionally, MTT assays on HFF-2 cell lines were performed for determining the biocompatibility of polymersomes. Finally, the antiproliferative activity of polymersomes was examined on MCF-7 breast cancer cell line. The obtained results showed that the average diameter of nanoparticles was less than 57 nm. The loading capacity and encapsulation efficiency of LOV was 16.1 ± 0.36% and 59.01 ± 0.78%, respectively. In vitro release study showed that the release rate of polymersomes depended on pH and was higher at lower pH than under neutral condition. The result of cell viability assay on the MCF-7 line proved that bare nanoparticles showed little inherent cytotoxicity whereas the LOV-loaded nanoparticles were cytotoxic.