Objective Triggered release of drugs from carrier systems in vivo is widely investigated for targeted tumor therapy.During the past decade, an ultrasound-sensitive liposome-microbubble pendant drug carrier system has been developed:microbubbles,decorated with liposomes that carry e.g.,doxorubicin,have been shown to release the drug in response to insonation.However,due to low drug load, so far,those pendant particles were only successful for suppressing tumor cell growth in vitro, in cell culture models.In this study, we were able to prepare particles with high doxorubicin load,using liposomes larger than the standard 80 nm Doxil/Caelyx formulation,and achieved successful inhibition of tumor growth in a subcutaneous murine tumor model.