MSc Defence: Characterization of Liposomal Release Temperature Using a Low Field Magnetic Resonance System

Student: Khalid Noori

Supervisor: Dr. Carl Kumaradas

Abstract:

The use of liposomes as chemotherapeutic carriers the subject of many research studies, with emphasis on enhancing the therapeutic index by increasing effect on cancer cells and reducing the effects on healthy ones. An important parameter to characterize for thermosensitive liposomes, TSLs, is the release temperature, Tr, the temperature at which liposomes release most of their content. By loading liposomes with a contrast agent such as Mn2+, a benchtop NMR system can be used to determine Tr through incremental heating, resulting in a sigmoidal curve for a relaxation rate enhancement vs. temperature graph. The motivation for the NMR approach stems from the potential to monitor content release in vivo using MR imaging. In this work, the release temperature is extracted from relaxometry measurements of Mn2+-loaded TSLs. Tr values
are then compared with transition temperature values, Tm, the temperature at which liposomes’ bilayer changes state, obtained by a standard technique.