Pon Janani Sugumaran
National University of Singapore, Singapore
Title: Ferromagnetic nanoparticles – A tool for high performance magnetic hyperthermia
Biography
Biography: Pon Janani Sugumaran
Abstract
Cancer is the second prominent cause of death worldwide, with approximately 9.6 million deaths in 2018. The mortality can be reduced if the cases are detected and treated in earlier stage. Existing treatment methods such as surgery, chemotherapy and radiotherapy can cause side effects like organ dysfunction, non-specificity, inflammation and they are non-localized. Magnetic nanoparticles (MNPs) tend to oscillate and dissipate energy in the form of heat when they are exposed to an alternating magnetic field, resulting in rise in local temperature. This property of localized heating is employed in magnetic fluid hyperthermia (MFH) for cancer treatment, in which the MNPs at the tumor site increase the temperature to 42-46oC, which denatures the proteins and affects the cell viability. MNPs can be targeted to tumor site by attaching with a suitable ligand which selectively binds to the tumor cell receptors and kills the cancer cells, without affecting the normal cells. The efficacy of MFH is higher compared to that of the conventional radiotherapy and chemotherapy. The synthesis of a MNP with good magnetization, biocompatibility and stability is important for MFH. The size, shape, composition, inter-particle spacing, confinement and surface functionalization are found to affect the surface absorption rate (SAR) of MFH. Superparamagnetic (SPM) particles of size <15 nm are commonly employed due to their good colloidal stability. Recent studies show that large MNPs have good magnetic response due to large hysteresis area and high magnetic saturation (Ms) and contribute to higher SAR values. They could heat-up the tumor site faster with a relatively smaller concentration of particles, low frequency and applied field compared to the SPM particles. But their usage is restricted due to their poor colloidal stability. This work addresses on the development of a universal carrier using Graphene oxide (GO), which could aid better colloidal suspension irrespective of the size or shape of the particle. We have developed a novel magnetic nanotube-GO nanocomposite, which could be stable even in biological environment and a high SAR value of 4322 W/g was obtained for a frequency of 400 kHz and applied field of 32 kA/m. The calculated Intrinsic Loss Power is 11.6 nH m2 kg-1, which is one of the highest reported value. The Nanotube-GO composite showed good biocompatibility in vitro and in vivo and has shown excellent anti-tumor efficacy in 4T1- tumor model mice by inhibiting their progression within a safe dosage range. The availability of functional groups in GO can be exploited for tagging and employed in targeted delivery.
