Nano-sized cationic polymeric magnetic liposomes significantly improves drug delivery to the brain in rats.

In recent years, cationic polymeric magnetic liposomes have shown greater stability and prolonged circulation half-life over traditional liposomes. Here, we examined the capability of cationic polymeric magnetic liposomes in delivering drugs into the brain under magnetic targeting with paclitaxel as the loaded agent. We found that the fabricated paclitaxel-loaded magnetic liposomes had a uniform diameter of 20 nm and were superparamagnetic. After they were injected into rats by the caudal vein, brain paclitaxel concentration increased 2-5 folds without magnetic targeting and 5-15 folds after magnetic targeting. The high brain concentration was maintained for more than 8 h, which was significantly longer than that for pure paclitaxel injection. When the liposomes were given via the internal carotid artery at 10% of the dose given via the caudal vein, paclitaxel in the brain was increased by 1.5 folds, indicating that intra-arterial administration enhanced delivery efficiency remarkably. Prussian blue staining of the cortex showed that the magnetic liposomes were aggregated in the cortex vasculature and the cortex cells were under magnetic targeting, indicating that the drugs were delivered across the nearly impermeable blood-brain barrier. These results showed that the nano-sized cationic polymeric magnetic liposomes are potential tools for magnetic drug delivery to the brain.