Multi-vortex magnetic nanoparticles for hyperthermia and magnetomechanical cancer-cell destruction

• Main Author: Tan, Chor Boon
• Other Authors: Lew Wen Siang
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Science::Physics::Electricity and magnetism
• Online Access: http://hdl.handle.net/10356/65662
• Institution: Nanyang Technological University

Magnetic nanoparticles have shown great potential for magnetic bio-medicinal applications, such as magnetic hyperthermia and magnetomechanical cancer cell destruction. The key advantage over conventional cancer therapy is the non-invasive and localization of treatment of the cancer tumor, thus minimizing any harmful side effects experienced by the patient. In this project, permalloy (Ni 80 Fe 20 ) ferromagnetic nanoparticles 500nm thick, 150nm and 350nm wide, were prepared via a template-assisted pulsed electrodeposition and differential chemical etching technique. Magnetic configuration simulations using Object Oriented Micromagnetic Framework (OOMMF) simulation software have revealed the existence of a triple vortex state in the NiFe magnetic nanoparticles. The weak demagnetizing field and magnetocrystalline anisotropy resulting from this triple-vortex state results in low remanence and coercivity values, reducing dipole-dipole interaction and increasing colloidal stability of the nanoparticles, and making it beneficial for cell-particle based bio-medicinal applications. The effectiveness of nanoparticles as an agent of cell death was also observed experimentally. Hyperthermia experiments conducted with NiFe nanoparticles measured Specific Absorption Rate (SAR) values of up to 1077Wg -1 at an alternating magnetic field of 377kHz. Torque-induced cell death was measured with HeLa cell viability under exposure to NiFe nanoparticles dropping to 73.36% under application of low frequency alternating magnetic fields. Hence we demonstrate the capability of the NiFe nanoparticles as a twin-functionalized agent for magnetomechanical cancer-cell destruction and magnetic hyperthermia.