Cancer is one of the challenges for today's medicine and therefore a great deal of effort is being put into improving known methods of treatment and developing new ones. A new method that has been proposed is magnetic hyperthermia where magnetic nanoparticles linked to the tumor dissipate heat when subjected to an alternating magnetic field and will thus increase the temperature of the tumor. This method makes the tumor more susceptible to radiation therapy and chemotherapy, or can be used to elevate the temperature of the tumor cells to cause cell death. The particles proposed for this are single core and often have a size in the range of 10 nm to 50 nm. To achieve an effective treatment the particles should have a narrow size distribution and the proper size. In this work, a theoretical model for predicting the heating power generated by magnetic nanoparticles was evaluated. The model was compared with experimental results for magnetite particles of size 15 nm to 35 nm dissolved in water. The properties of the particles were characterized, including measurements of the magnetic saturation, the effective anisotropy constant, average size and size distribution. To evaluate the results from the model the AC susceptibility and heating power were experimentally determined. The model is a two-step model. First the out-of-phase component of the AC susceptibility as a function of frequency is calculated. Then this result is used to calculate the heating power. The model gives a correct prediction of the shape of the out-of-phase component of the susceptibility but overestimates its magnitude. Using the experimentally determined out-of-phase component of the susceptibility, the model estimation of the heating power compares quite well with the measured values.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-199055 |
| Date | January 2013 |
| Creators | Andersson, Mikael |
| Publisher | Uppsala universitet, Fasta tillståndets fysik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | UPTEC Q, 1401-5773 ; 13001 |
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