Design and test of an ultrasonic experimental set-up for controlled delivery of encapsulated chemotherapy

Applying ultrasound on drug-loaded sonosensitive liposomes offers new possibilities for treating cancer. In vitro experiments were performed in the present study to define an index of inertial cavitation which could be used to monitor the delivery of drugs. This index could also be used to assess the sonosensitivity of new formulations of liposomes. Experiments were then carried out in rats bearing subcutaneous abdominal tumors. Based on pharmacokinetic and biodistribution studies, a period of 48 hours was chosen between the injection of the liposomes and the exposure to ultrasound. At the injected doses, liposomes slowed down significantly the tumor development. Ultrasound combined with liposomes seemed to contribute to the tumor control. However, the important efficacy of liposomes alone and the eventual weak interactions with ultrasound prevent to guarantee that the effect of ultrasound is significant. (C) 2009 Elsevier Masson SAS. All rights reserved.