Enhanced antitumor efficacy, biodistribution and penetration of docetaxel-loaded biodegradable nanoparticles

Abstract

To investigate the antitumor effect, biodistribution and penetration in tumors of docetaxel (DOC)-loaded polyethylene glycol–poly(caprolactone) (mPEG–PCL) nanoparticles on hepatic cancer model, DOC-loaded nanoparticles (DOC-NPs) were prepared with synthesized mPEG–PCL by nano-precipitated method with satisfactory encapsulation efficiency, loading capacity and size distribution. The fabricated nano-drugs were effectively transported into tumoral cells through endocytosis and localized around the nuclei in the cytoplasm. In vitro cytotoxicity test showed that DOC-NPs inhibited the murine hepatic carcinoma cell line H22 in a dose-dependent manner, which was similar to Taxotere®, the commercialized formulation of docetaxel. The in vivo biodistribution performed on tumor-bearing mice by NIRF real-time imaging demonstrated that the nanoparticles achieved higher concentration and longer retention in tumors than in non-targeted organs after intravenous injection. The immunohistochemical analysis demonstrated that the nanoparticles located not only near the tumoral vasculatures, but also inside the tumoral interior. Therefore, DOC-NPs could penetrate into tumor parenchyma, leading to high intratumoral concentration of DOC. More importantly, the in vivo anti-tumor evaluation showed that DOC-NPs significantly inhibited tumor growth by tumor volume measurement and positron emission tomography and computed tomography (PET/CT) imaging observation. Taken together, the reported drug delivery system here could shed light on the future targeted therapy against hepatic carcinoma.