Investigations of the Size Effects on the Relaxation Rates of Polymer Coated Magnetic Nanoparticles for Hyperthermia

Clemson University, Clemson SC

Investigators

Abstract

ID: MPS/DMR/BMAT(7623) 0907167 PI: Mefford, Olin T. ORG: Clemson University Title: Investigations of the Size Effects on the Relaxation Rates of Polymer Coated Magnetic Nanoparticles for Hyperthermia INTELLECTUAL MERIT: The PI proposes to investigate the factors affecting magnetic hyperthermia in nano-scale polymer-coated magnetic oxide particles. Magnetic particles acquire thermal energy from applied electromagnetic radiation and if the particles can be targeted into cancerous cells these cells can be killed by heating them to moderate temperatures (> 40 °C) without harming the surrounding tissue. The rate of response of the particle-coating complex to an alternating electromagnetic (EM) field is related to its relaxation time, and the materials issues that govern this behavior are not fully understood. A major objective of the proposed research is the acquisition of a fundamental understanding of the relaxation mechanisms. The sizes of the magnetic core and polymeric stabilizing layer can both greatly influence the response of these materials to EM radiation. However, it is not well understood how the ratio of these two dimensions affects the thermal response to different magnetic fields and field frequencies. The PI proposes to develop model systems of coated and non-coated magnetic nanoparticles, measure how the sizes and size distributions of the core particles and the polymer/particle complexes affect the relaxation rates of the suspensions, measure the heating rates of different nanoparticle systems in solvent systems similar to those found in the human body and tailor the sizes of the magnetic core and the polymer brushes to optimize heating at specific heating frequencies and fields. BROADER IMPACTS: The topic of the proposal is of current interest, and there will be abundant opportunities for dissemination of results in conferences and in publications. The work provides a foundation for pharmaceutical companies to develop new nanoparticle-based therapies and imaging agents. A successful outcome will impact not only hyperthermia research but also magnetism, polymer chemistry, and colloid chemistry. This project is at the intersection of physics, chemistry, and biology and thus provides a platform for interdisciplinary training of students. In addition to the graduate students on the project, it will provide opportunities for two undergraduate research students. The development of good writing and oral presentation skills is critical for the development of future scientists and engineers. One of the goals of the project is to provide opportunities for the students to present their work at national and international meetings. The PI will participate in the J. E. Sirrine Summer Program that exposes South Carolina high-school students to materials science research. It is expected that his group will mentor two of these students. One of the goals of this work is to develop teaching tools for Clemson representatives to travel across the Southeast to educate high school students on research in bionanomaterials.