Ultrasound contrast agents (UCAs) microbubbles (MBs) can be preloaded with a therapeutic agents to achieve high efficiency for US-triggered drug delivery. Here we use fluorescence labeling as a substitute for theraputic drug, and use ultra high-speed fluorescence imaging for time-resolved observation of the drug release. Two configurations of drug delivery vehicles were investigated-I) lipid-shelled (unloaded) MBs and II) liposome-loaded (loaded) MBs. Different release phenomena were observed. The dynamics of release was found to be strongly dependent on ultrasonic parameters and on the MB's shell properties. MBs shrinkage following US exposure was analyzed and it indicated close correlation with the fluorescence release. This study provides valuable insights into the drug release mechanisms for ultrasound-controlled drug delivery.

controlled release, drug delivery, fluorescence labeling, high-speed fluorescence imaging, release dynamics
dx.doi.org/10.1109/ULTSYM.2012.0510, hdl.handle.net/1765/58940
2012 IEEE International Ultrasonics Symposium, IUS 2012
Department of Cardio-Thoracic Surgery

Luan, Y, Gelderblom, E, Lajoinie, G, Skachkov, I, Dewitte, S, Geers, B, … de Jong, N. (2012). Characterizing ultrasound-controlled drug release by high-speed fluorescence imaging. Presented at the 2012 IEEE International Ultrasonics Symposium, IUS 2012. doi:10.1109/ULTSYM.2012.0510