Rapid dynamicR1/R2*/temperature assessment: a method with potential for monitoring drug delivery
| Autor: | Clemens Bos, Chris Oerlemans, Mario Ries, Alexandru Cernicanu, Cyril Lorenzato, Chrit T. W. Moonen, Baudouin Denis de Senneville |
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| Rok vydání: | 2014 |
| Předmět: |
Relaxometry
Liposome Gadolinium-Chelate Gadolinium chemistry.chemical_element Thermosensitive liposomes 010402 general chemistry 01 natural sciences Focused ultrasound 030218 nuclear medicine & medical imaging 0104 chemical sciences 03 medical and health sciences 0302 clinical medicine Nuclear magnetic resonance chemistry Temporal resolution Drug delivery Molecular Medicine Radiology Nuclear Medicine and imaging Spectroscopy Biomedical engineering |
| Zdroj: | NMR in Biomedicine. 27:1267-1274 |
| ISSN: | 0952-3480 |
| DOI: | 10.1002/nbm.3182 |
| Popis: | Local drug delivery by hyperthermia-induced drug release from thermosensitive liposomes (TSLs) may reduce the systemic toxicity of chemotherapy, whilst maintaining or increasing its efficacy. Relaxivity contrast agents can be co-encapsulated with the drug to allow the visualization of the presence of liposomes, by means of R2*, as well as the co-release of the contrast agent and the drug, by means of R1, on heating. Here, the mathematical method used to extract both R2* and R1 from a fast dynamic multi-echo spoiled gradient echo (ME-SPGR) is presented and analyzed. Finally, this method is used to monitor such release events. R2* was obtained from a fit to the ME-SPGR data. Absolute R1 was calculated from the signal magnitude changes corrected for the apparent proton density changes and a baseline Look–Locker R1 map. The method was used to monitor nearly homogeneous water bath heating and local focused ultrasound heating of muscle tissue, and to visualize the release of a gadolinium chelate from TSLs in vitro. R2*, R1 and temperature maps were measured with a 5-s temporal resolution. Both R2*and R1 measured were found to change with temperature. The dynamic R1 measurements after heating agreed with the Look–Locker R1 values if changes in equilibrium magnetization with temperature were considered. Release of gadolinium from TSLs was detected by an R1 increase near the phase transition temperature, as well as a shallow R2* increase. Simultaneous temperature, R2* and R1 mapping is feasible in real time and has the potential for use in image-guided drug delivery studies. Copyright © 2014 John Wiley & Sons, Ltd. Additional supporting information may be found in the online version of this article at the publisher’s web site. |
| Databáze: | OpenAIRE |
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