Characterization and preparation of core–shell type nanoparticle for encapsulation of anticancer drug

The aim of this study is to prepare delivery vehicles of paclitaxel using low molecular weight water-soluble chitosan (LMWSC) and evaluate them as an anticancer drug delivery system. LMWSC was modified with methoxy polyethylene glycol (LMWSC-MPEG, ChitoPEG), and then it was conjugated with cholesterol (LMWSC-MPEG-Chol). Core–shell type LMWSC-MPEG-Chol nanoparticles (LMWSC-NPs) were prepared by the dialysis method, and the core–shell structure was confirmed by 1H NMR analysis. To this polymer, paclitaxel was encapsulated and core–shell type nanoparticles were prepared. The release tests indicated that release of paclitaxel from the core–shell type nanoparticles and its transport across the dialysis membrane was slower than dialysis of free paclitaxel. In a cytotoxicity study using CT26 cell, the paclitaxel-encapsulated core–shell type nanoparticles (LMWSC-NPs) showed a toxicity against tumor cells similar to paclitaxel itself. The results of a tumor inhibition test with CT26 implanted upon mouse tumor models in vivo indicated that the application of a dose of 10 mg/kg of LMWSC-NPT showed a superior survival rate, and a slower tumor growth than when paclitaxel alone was administered, although the tumor growth and survival rate were not significantly changed at a dose of 2 mg/kg. The LMWSC-NPT dose above 10 mg/kg showed a superior antitumor activity.