NSF REU Site Renewal: Interfaces and Surfaces
Summer 2015
Faculty Advisor Project Submission
Heterobifunctional polymers for surface modification of iron oxide nanoparticles
Faculty Advisor: Prof. Thompson Mefford (Department of Materials Science and Engineering)
Research Project: Magnetic nanoparticles are an ideal material for bioimaging,1 therapy,2 and delivery.3
These blossoming technologies are not possible without designing and synthesizing specialized materials
to stabilize the magnetic nanoparticles in biological environments. For the stabilizing layer, the material
must be biologically inert and sufficient steric hindrance to provide a long circulation time in the body. To
increase efficiency of materials used in biological imaging, therapy and delivery, the surface must be
enhanced with biologically targeting and labeling molecules to both increase the concentration of the
particles in the desired location of the body and monitoring the particles’ fate. We have recently reported
new binding chemistries that provide robust anchoring to the surface iron oxide nanoparticles in a variety
of biological media.4 This system has been extended via the production of a heterobifunctional
polyethylene oxide (PEO) using nitroDOPA as a robust anchoring group on one end and an alkyne as the
reactive surface for additional application specific modification.
Research Expectations for REU Participant: The REU student involved in this project will explore the
potential for these multifunctional nanoparticles allowing them to be utilized in a variety of research
fields because of the efficiency and ease of modification that is inherit in the Huisgen 1,3-dipolar
cycloaddition between an azide and alkyne, commonly known as ‘click’ chemistry. Students involved
with this project will utilize this adaptive system to explore the effect of end group modification on the
interface between these polymer-particle composites and biological media. For example, the student will
utilize scanning electron microscopy, dynamic light scattering, fluorescent imaging, and AC magnetic
relaxometry to observe the effect of near-IR dyes modified on the surface of the complexes in biologically
relevant media.
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Pankhurst, Q. A.; Thanh, N. K. T.; Jones, S. K.; Dobson, J. Progress in Applications of Magnetic
Nanoparticles in Biomedicine. J. Phys. D: Appl. Phys. 2009, 42, 224001.
Stone, R.; Willi, T.; Rosen, Y.; Mefford, O. T.; Alexis, F. Targeted Magnetic Hyperthermia.
Therapeutic Delivery 2011, 2, 815–838.
Krishnan, K. M. Biomedical Nanomagnetics: a Spin Through Possibilities in Imaging, Diagnostics,
and Therapy. Ieee T Magn 2010, 46, 2523–2558.
Saville, S. L.; Stone, R. C.; Qi, B.; Mefford, O. T. Investigation of the Stability of Magnetite
Nanoparticles Functionalized with Catechol Based Ligands in Biological Media. J. Mater. Chem.
2012, 22, 24909.