Induction heating properties of magnetic nanoparticles, and biomedical application for in vitro hyperthermia

• Main Authors: Chia-Wei Lee, 李嘉偉
• Other Authors: Chao-Ming Fu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/19911536846932195307

碩士 === 國立臺灣大學 === 物理研究所 === 97 === The superparamagnetic Fe3O4 nanoparticles have been widely utilized for biomedical applications so far, such as for magnetically separating of bio-entities, contrast agents in magnetic resonance imaging, magnetically targeting of chemotherapeutic drugs, hyperthermia therapy, etc. Besides, the Fe3O4 nanoparticles have been shown superior heating properties under altering magnetic field, which implies hyperthermia therapy for clinical cancer treatment. In this study, we controlled the titration rate, pH and neutralized the surface charge by purging agents in order to synthesize the superparamagnetic Fe3O4 nanoparticles possessed superior heating properties. Their particle size are in the range of 14 - 32 nm with a mean size close to 21 nm, and the PEG-coated particle size are about 30 - 50 nm. Moreover, the saturation magnetization are about 65 - 75 emu/g, coercivity are less than 18 Oe, the residual magnetization are less than 3 emu/g. After the heating experiment under altering magnetic field of 100 kHz, 10 Oe, we could observe the superparamagnetic Fe3O4 nanoparticles, purged to pH~3.5 by alcohol, showed the optimal specific absorption rate (SAR) is 23.98 W/g, the quantity of SAR/Q is 146.15 W/g. In addition, we injected these superparamagnetic Fe3O4 nanoparticles into the cells culture medium of renal cell carcinoma (RCC), and applied the altering magnetic field of 100 kHz, 15 Oe to perform in vitro hyperthermia. This samples of RCC medium, concentration with Fe3O4 nanoparticles are in the range of 0.98 - 3.33 mg/ml, were heating from 37 ℃ to 41.2 - 47.5 ℃ for 30 min of whole course. However, the survival rates (SR) of RCC are from 82.3% to 0%. Furthermore, the biomedical studies had been shown the organisms can''t be applied a radio-frequency (RF) magnetic field exceed the limitation of H×f < 6.09×10^6 Oe/sec, we utilized a proper RF magnetic field,100 kHz, 15 Oe, to achieve the prospective results in this study.