Group Project Overview
- My main research project is modifying polymer ligands for functionalization to the surface of iron oxide nanoparticles. I am involved in research with an experimental cancer therapeutic system known as magnetic hyperthermia, which involves selective heating of cancerous tissues using the iron oxide nanoparticles. I am also involved in using these particles as contrast enhancement agents for diagnosis assistance using MRI. My third research project is crosslinking these iron oxide nanoparticles into a magnetically modulated nanosponge. The pore size of this sponge can be modified based on applied magnetic field. My final research project involves using a hormonal treatment to the surface of ship hulls as a preventive binding agent against fouling from urchins, barnacles, and other sea-born creatures.
- I am working on the project of Magnetic Hyperthermia. The project is divided into 3 main parts: Bin makes magnetic nanoparticles and Steven attaches the polymer to it and I measure the heating rate of these particle using the HOTSHOT instrument from Ameritherm Inc. Followed by that, I do the Specific Absorption Rate (SAR) calculations of our samples.
- By attaching a molecule like 'Flotin' which has affinity towards cancer cells to these particles, they can be specifically used to target cancer cells in the body. These particles are heated by an external AC magnetic field. The two heat mechanisms are Neel relaxation and Brownian relaxation.
- Regarding my progress so far, Bin made 4 sizes of particles (6.5nm, 7.5nm, 8.5nm and 11nm) and Steven attached (550 PEG, 1000 PEG, 2000 PEG and 5000 PEG) on each of these nanoparticles (in total 16 samples). I have measured the heating rates of all of these and calculated their SAR. In the near future, we are working on improving our present results by studying the effect of various parameters like field amplitude, number of coil turns, current amplitude and capacitance.
- Another project I am working on is the fabrication of gold coated magnetite nanoparticles in which I again utilize Bin’s particles. These particles can be again used in various bioapplications like drug delivery, hyperthermia treatment of cancer, MRI contrast enhancement. A couple of our samples have been sent to University of Missouri where they are modifying our samples to verify its efficiency in killing cancer cells.
- Mefford, O. T.; Vadala, M. L.; Carroll, M. R. J.; Mejia-Ariza, R.; Caba,
B. L.; St. Pierre, T. G.; Woodward, R. C.; Davis, R. M.; Riffle, J. S.,
Stability of Polydimethylsiloxane-Magnetite Nanoparticles Against
Flocculation: Interparticle Interactions of Polydisperse Materials.
Langmuir 2008, 24(9), 5060-5069.
- Mefford, O. T.; Carroll, M. R. J.; Vadala, M. L.; Goff, J. D.;
Mejia-Ariza, R.; Saunders, M.; Woodward, R. C.; St. Pierre, T. G.; Davis, R. M.;
Riffle, J. S., Size Analysis of PDMS-Magnetite Nanoparticles Complexes:
Experiment and Theory. Chemistry of Materials 2008, 20, 2184-2191.
- Mefford, O. T.; Woodward, R. C.; Goff, J. D.; Vadala, T. P.; St. Pierre, T.
G.; Dailey, J. P.; Riffle, J. S., Field Induced Motion of Ferrofluids
through Immiscible Viscous Media: Testbed for Restorative Treatment of
Retinal Detachment. Journal of Magnetism and Magnetic Materials 2007,