Targeted ultrasound-mediated delivery of nanoparticles: on the development of a new HIFU-based therapy and imaging device.

Ultrasound-mediated delivery (USMD) is an active research topic, as researchers develop applications for therapeutic ultrasound in addition to thermal ablation. In USMD, ultrasound is used in conjunction with microbubbles and drugs, nanoparticles, siRNA, pDNA, stem cells, etc., to facilitate their cellular delivery and uptake using pressure and temperature-mediated mechanisms to bring about a desired therapeutic effect. To investigate the potential of targeted USMD of nanoparticles, pDNA, and stem cells for cardiovascular and other applications, a general-purpose preclinical research tool, therapy imaging probe system (TIPS) was designed. It consists of a wideband annular array, a small-animal acoustic coupler, a motorized positioning system, integrated control software for ultrasound image-guided treatment planning and execution, and triggering electronics that allow ECG and respiration-gated ultrasound exposures. TIPS was then used to enhance delivery of nanoparticles into the murine myocardium and heart vessel walls to demonstrate the feasibility of the technology, pave the way for additional basic research in cardiovascular USMD, and begin to explore the requirements that USMD devices will have to meet to be useful in a clinical setting.