Cavitation-induced drug delivery in tumors for cancer chemotherapy: Phantom studies

One of the major problems of cancer chemotherapy is slow diffusion of anti-cancer drugs in the interstitium and their poor penetration from blood through tumor capillary wall and cancer cell membrane. To enhance delivery of the drugs in cancer cells we proposed to use interaction of exogenous microparticles with laser or ultrasonic radiation. This interaction results in cavitation near the particles upon certain irradiation conditions. Our previous pilot studies demonstrated feasibility of enhanced delivery of model and real anti-cancer drugs in tissues in vitro and in vivo if laser pulsed or ultrasonic radiation is applied. In this work we performed studies in tissue phantoms in order to find optimal parameters that can be used for safe and efficient delivery of anti-cancer drugs in tumors. Water solutions and gelatin were used as tissue phantoms with well-controlled parameters. Cavitation in the phantoms was studied by using optical and ultrasound techniques. Results of our studies indicate that efficient cavitation-driven drug delivery can be achieved with no or minimal damage to normal tissues.