Development of high drug loaded and customizing novel nanoparticles for modulated and controlled release of paclitaxel

Purpose: The objective of this study was to develop a custom-tailored polymeric drug delivery system for paclitaxel, employing a novel biodegradable block co-polymer (P), intended to be intravenously administered, capable of improving therapeutic index of the drug and devoid of the adverse effect of an uncontrolled release.

Methods: Paclitaxel loaded nanoparticles (PTX-NPs) were prepared by a modified nanoprecipitation method and emulsification-solvent evaporation method. Our approach involves a focusing on the formulation parameters that can be modified in order to obtain completely customized NPs in terms of size, zeta-potential, drug content and release profile. The biocompatibility and anti-proliferative efficiency of PTX-NPs against glioblastoma cell line were evaluated in vitro by MTS.

Results: All formulations showed spherical nanometric (<200 nm), monodisperse (∼0.1), Poly (Ethylene Glycol) (PEG)-coated and negatively charged particles. Selected NPs revealed higher PTX content (up to 24%) in comparison with polyester-based NPs. The release behaviour of PTX from the developed NPs exhibited an approximately first-order profile, without initial burst and characterized by a slow and constant release. Hydrophobic character of the NPs can be set in order to achieve a slower and more controlled release for a prolonged period of time. PTX-NPs were hemocompatible and had significant in vitro anti-tumoral activity against human primary glioblastoma cell line (U-87 MG); cytotoxicity was in time- and drug concentration- dependent manner.

Conclusions: The developed drug delivery system proved to be suitable for intravenous administration. NPs characteristics can be customized to obtain high PTX loaded NPs that can improve therapeutic index and avoid an uncontrolled release.