MRI contrast variation of thermosensitive magnetoliposomes triggered by focused ultrasound: a tool for image-guided local drug delivery
Article first published online: 20 DEC 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Contrast Media & Molecular Imaging
Volume 8, Issue 2, pages 185–192, March/April 2013
How to Cite
Lorenzato, C., Cernicanu, A., Meyre, M.-E., Germain, M., Pottier, A., Levy, L., de Senneville, B. D., Bos, C., Moonen, C. and Smirnov, P. (2013), MRI contrast variation of thermosensitive magnetoliposomes triggered by focused ultrasound: a tool for image-guided local drug delivery. Contrast Media Mol Imaging, 8: 185–192. doi: 10.1002/cmmi.1515
- Issue published online: 21 NOV 2012
- Article first published online: 20 DEC 2012
- Manuscript Accepted: 10 OCT 2012
- Manuscript Revised: 28 SEP 2012
- Manuscript Received: 31 JUL 2012
- local drug delivery;
- thermosensitive liposomes
Improved drug delivery control during chemotherapy has the potential to increase the therapeutic index. MRI contrast agent such as iron oxide nanoparticles can be co-encapsulated with drugs in nanocarrier liposomes allowing their tracking and/or visualization by MRI. Furthermore, the combination of a thermosensitive liposomal formulation with an external source of heat such as high intensity focused ultrasound guided by MR temperature mapping allows the controlled local release of the content of the liposome. MRI-guided high-intensity focused ultrasound (HIFU), in combination represents a noninvasive technique to generate local hyperthermia for drug release. In this study we used ultrasmall superparamagnetic iron oxide nanoparticles (USPIO) encapsulated in thermosensitive liposomes to obtain thermosensitive magnetoliposomes (TSM). The transverse and longitudinal relaxivities of this MRI contrast agent were measured upon TSM membrane phase transition in vitro using a water bath or HIFU. The results showed significant differences for MRI signal enhancement and relaxivities before and after heating, which were absent for nonthermosensitive liposomes and free nanoparticles used as controls. Thus, incorporation of USPIO as MRI contrast agents into thermosensitive liposomes should, besides TSM tumor accumulation monitoring, allow the visualization of TSM membrane phase transition upon temperature elevation. In conclusion, HIFU under MR image guidance in combination with USPIO-loaded thermosensitive liposomes as drug delivery system has the potential for a better control of drug delivery and to increase the drug therapeutic index. Copyright © 2012 John Wiley & Sons, Ltd.