Study of Thermally Targeted Nano-Particle Drug Delivery for Tumor Therapy

The efficacy of cancer chemotherapeutics could be greatly enhanced by thermally targeted nanoparticle liposome drug delivery system. The tumor microvasculature response to hyperthermia and its permeability to the nano-liposomes were studied using the 4T1 mouse model and confocal fluorescence microscopy. Based on the experimental results, a new theoretical model was developed to describe the distributions of both the liposomal and free drug released as liposomes broke in tumor for treatment evaluation. In this model, the tumor was divided into two regions: peripheral and central. The drug effect on the tumor cell apoptosis and necrosis was considered. Upon the experimental validation, the model was used to simulate drug distribution in the tumor under either the hyperthermic or the alternate freezing and heating condition. Results showed that hyperthermia alone only enhanced drug accumulation in the tumor periphery and therefore more serious tumor damage induced in the region. But the tumor cells in the central region were hardly damaged due to the lack of drug diffusion. The alternate freezing and heating was proposed to aid the nanoliposomal drug delivery, and better results were found.