Cellular Uptake and In Vitro Drug Release Studies on Paclitaxel-Loaded Poly(caprolactone)-Grafted Dextran Copolymeric Nanoparticles

Drug-Loaded Photosensitizer-Chitosan Nanoparticles for Combinatorial Chemo- and Photodynamic-Therapy of Cancer

In this study we have developed biodegradable polymeric nanoparticles (NPs) containing the cytostatic drugs mertansine (MRT) or cabazitaxel (CBZ). The NPs are based on chitosan (CS) conjugate polymers synthesized with different amounts of the photosensitizer tetraphenylchlorin (TPC). These TPC–CS NPs have high loading capacity and strong drug retention due to π–π stacking interactions between the drugs and the aromatic photosensitizer groups of the polymers. CS polymers with 10% of the side chains containing TPC were found to be optimal in terms of drug loading capacity and NP stability. The TPC–CS NPs loaded with MRT or CBZ displayed higher cytotoxicity than the free form of these drugs in the breast cancer cell lines MDA-MB-231 and MDA-MB-468. Furthermore, light-induced photochemical activation of the NPs elicited a strong photodynamic therapy effect on these breast cancer cells. Biodistribution studies in mice showed that most of the TPC–CS NPs accumulated in liver and lungs, but they were also found to be localized in tumors derived from HCT-116 cells. These data suggest that the drug-loaded TPC–CS NPs have a potential in combinatory anticancer therapy and as contrast agents.

Characterization and in-vitro bioactivity evaluation of paclitaxel-loaded polyester nanoparticles

Paclitaxel, an antimicrotubular agent used in the treatment of ovarian and breast cancer, was encapsulated in nanoparticles of poly(DL-lactide-co-glycolide) and poly(ε-caprolactone) polymers using the double emulsion-solvent evaporation technique. The morphology, size distribution, drug encapsulation efficiency, thermal degradation and in-vitro drug release profile were characterized. High-performance liquid chromatography was used to determine the drug encapsulation efficiency and in-vitro drug release profile. MCF-7 breast cancer cells were used to evaluate the cytotoxicity (MTT assay), the cellular uptake and the cell cycle. The particle size was in the range of 200-400 nm. Poly(lactide-co-glycolide) nanoparticles showed more effective cellular uptake compared with those of poly(ε-caprolactone). Unloaded nanoparticles were found to be cytocompatible on MCF-7 cells and paclitaxel formulations showed efficacy in killing MCF-7 cells. Paclitaxel-loaded nanoparticles induced the release of the drug-blocking cells in the G2/M phase. Paclitaxel-loaded nanoparticles may be considered a promising drug delivery system in the evaluation of an in-vivo model.