Towards a complete magnetic hyperthermia technology
as a novel cancer treatment system.
Doctoral thesis, UCL (University College London).
The subject of this thesis explores the development of magnetic hyperthermia technology at the preclinical stage. Magnetic hyperthermia uses magnetic nanoparticles as functionalisable agents, targeted to cancer sites. They can then be non-invasively activated by alternating magnetic fields to deliver lethal doses of heat to the cancer cells with minimal damage to healthy tissue. This work concentrates on several complex aspects concealed within the conceptual simplicity of magnetic hyperthermia. One key aspect lies in the design of the alternating magnetic field generator. Here, a novel device, the MACH system, that exceeds currently available AC magnetic field generators in performance, form factor and versatility is described and evaluated. Electronic characteristics for 5 different configurations, ranging from a solenoidal to a flat applicator, are presented. Furthermore, magnetic field distributions in and around the applicator coil were modeled for all real configurations and two hypothetical models. These models revealed that in certain configurations high magnetic field gradients exist, prompting careful positioning of samples in real experiments. Sixteen commercially available iron-oxide nanoparticles with potential as hyperthermia candidates were characterised using photon correlation spectroscopy, atomic emission spectroscopy, asymmetric field-flow fractionation, spectrophotometric iron trace analysis, calorimetric analysis and magnetometry. To compare the heating rates of nanoparticle samples, a new design rule parameter, the intrinsic loss parameter (ILP), was introduced to replace the status quo, the equipment-dependent specific absorption rate (SAR). The results highlight a magnetic crystal size dependence with ILP, and also imply that some commercial samples are approaching the best achievable results. Finally, the commercial potential of the MACH system is evaluated in light of new applications that exploit its unique, distinguishing features. Hyperthermia cancer treatment was concluded to have the greatest potential on the long run, with the adhesives and thermoset polymer industry being lucrative short-term targets.
|Title:||Towards a complete magnetic hyperthermia technology as a novel cancer treatment system|
|Additional information:||Permission for digitisation not received|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Physics and Astronomy|
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