Noninvasive Monitoring of Ultrasound Induced CuO Nanoparticles Release from Polymeric Nanocarriers

Hyperthermia is a treatment used as a complimentary cancer therapy. During this procedure, the tumor tissue is heated, either to ablative temperatures or to a level of thermal sensitization, yielding localized damage. Numerous studies have suggested the use of nanoparticles to reinforce the conventional hyperthermia methods in order to improve thermal discrimination between tumor and surrounding healthy tissue and to achieve better internal heat distribution. For such procedures, noninvasive continuous monitoring of the treated area is indispensable.

The main goal of this research is to develop an image guided noninvasive approach for monitoring Ultrasonic induced hyperthermia augmented by copper oxide nanoparticles (CuO NPs). These CuO NPs can also serve as a Magnetic Resonance Imaging (MRI) contrast enhancing agent thus potentially allowing mapping of their spatial distribution. For this aim, CuO NPs were first loaded into PEG-b-PLA micelles. Then, using a therapeutic ultrasonic transducer (1MHz) samples of solutions containing the micelles loaded with the NPs were sonicated and their temperature was elevated to about 50^oC. Resulting from the ultrasonic hyperthermia, NPs release was detected and quantified by colorimetric methods as a function of time and temperature.

The results have shown that in addition to the temperature elevation, the ultrasound triggered a release of the CuO NPs from the micelles. This was also verified by comparison to the non-treated samples. The controlled release process was also visible by MR imaging using a 9.4T scanner. The combined diagnostic and cytotoxic activities of the CuO NPs can potentially lead to the development of a new noninvasive strategy for cancer theranostics.