Thermosensitive Mn~(2+)- Liposomes for MR-Guided Hyperthermia - Solvent-Dependent Mn~(2+)- Release.

摘要

Newly designed phosphatidylglyceroglycerol-based liposomes are shown to be a temperature sensitive contrast agent for MRI when MR-active manganese(II)ions are trapped inside. At the therapeutic temperature of hyperthermia of 42 - 43°C the encapsulated Mn~(2+) can be detected by T, changes in a MRI-Hyperthermia hybrid-system. The physical properties of the liposomes are characterized by lipid composition, size, morphology and not least solvent composition. Dependent on the solvent two mechanisms for the T_t changes can be found, enhanced water exchange through the lipid membrane or release of Mn~(2+).Our results indicate that our new liposomal system has the potentiality to improve temperature monitoring of hyperthermia and thus the therapeutic outcome. Moreover, the liposomes may also be used for specific release of chemotherapeu-tics by moderate hyperthermia.