Nanosized Cationic Polymeric Magnetic Liposomes for Drug Delivery to Brain
Ming Zhao Department of Neurosurgery
First Affiliated Hospital to PLA General Hospital, Beijing, China
Abstract:
Our previous research found that cationic polymeric magnetic liposomes, made from octadecyl quaternized caroxymethyl chitosan, Fe3O4 ferrofluid and cholesterol, showed more stability and prolonged circulation half-life over traditional liposomes. In this study, we tested their capability of carrying drugs into brain under magnetic targeting. Paclitaxel was used as the loaded agent and analyzed by HPLC. The fabricated paclitaxel-loaded magnetic liposomes showed a uniform diameter of 20nm and superparamagnetism. They released drugs for more than 15 days in vitro. After they were injected into rats by caudal vein, the paclitaxel concentration in brain increased for 2-5 folds without magnetic targeting and for 5-15 folds after magnetic targeting. Besides, the high concentration in brain maintained for more than 8 hours, significantly longer than pure paclitaxel injection. Furthermore, when the liposomes were given by internal carotid artery at 10% dose of that given by vein, the paclitaxel in brain increased by 1.5 folds, indicating the interventional administration can enhance the delivery efficiency remarkably. Prussian blue staining of the cortex showed that the magnetic liposomes aggregated in the cortex vasculature and the cortex cells under magnetic targeting, which conformed that they delivered drugs across the nearly impermeable blood-brain barrier. These results showed the nanosized cationic polymeric magnetic liposomes are potential tools for magnetic drug delivery to the brain.
Keywords: Magnetic liposome; Polymeric liposome; Paclitaxel; Brain
