New biocompatible aliphatic polyesters as thermosensitive drug nanocarriers. Application in targeting release pharmaceutical systems for local cancer treatment

Abstract

In the present study a new drug delivery system for the treatment of local cancer was developed. Two aliphatic polyesters namely poly(propylene adipate) (PPAd) and poly(propylene pimelate) (PPPim), were used as carriers in order to prepare nanoparticles loaded with paclitaxel. The starting materials as well as the nanoparticles were characterized with DSC, SEM and WAXD techniques. The nanoparticles had a mean particle size of 160-190nm and characterized for drug loading content, efficiency and in vitro dissolution at 37°C and 42°C in two different pH buffer solutions (pH 7.4 and pH 6.0). Results showed enhanced release rate of paclitaxel at 42°C compared to 37°C in both pH conditions. The degree of crystallinity plays also an important role to paclitaxel release. The cytotoxicity of the prepared paclitaxel/ polyester nanoparticles was studied in comparison with control samples using two cancer cell lines like Human hepatoma (HepG2) cells and Human Cervical Adenocarcinoma Cells (HeLa). In both cases it was found that cells are in the phase of necrosis or apoptosis after 20h of incubation. Finally, the temperature is also an important factor since this behaviour is faster in 42°C than in 37°C, indicating that the studied polyesters could act as thermosensitive carriers. © 2012 Karavelidis V, et al.