(420s) PEG-Based Functionalization of Iron Oxide Nanoparticles Using the ISOFURE Methodology

PEG-based
Functionalization of Iron Oxide Nanoparticles Using the ISOFURE Methodology

Robert J. Wydra,
David S. Spencer, J. Zach Hilt

Department of
Chemical and Materials Engineering, University of Kentucky

Magnetic nanoparticles, with
their unique physical properties, are being studied for a wide range of
biomedical applications such as imaging, targeted delivery, and thermal therapy
of cancer.  Surface modification plays an essential role in determining the
success of the particles in their application by improving the stability,
preventing agglomeration, improving biocompatibility, and providing additional
functionality (e.g. targeting antibodies).  Poly(ethylene glycol) (PEG) based
functionalization is common for biological applications as a mean to prevent
protein adsorption and thus improve the circulation time and minimize host
response.  Previous work has investigated using a solution based atom transfer
radical polymerization (ATRP) to successfully create PEG-iron oxide core-shell
nanoparticles.  In this study, a novel strategy to isolate, functionalize, and
subsequently release (ISOFURE) functionalized nanoparticles was harnessed. 
Initially iron oxide nanoparticles were synthesized using the facile co-precipitation
technique.  The bare particles were entrapped in a biodegradable
poly(β-amino ester) (PBAE) hydrogel.  While isolated, the particles were
modified with poly(ethylene glycol) (MW=400) dimethacrylate (PEG400DMA) and other monomers
using ATRP.  Following the reaction, the PBAE hydrogel network was
degraded in water, and the functionalized nanoparticles were collected for
characterization.  The particles were characterized using Fourier transform
infrared spectroscopy, to verify surface functionalization; thermal gravimetric
analysis, to quantify mass percent of coating; dynamic light scattering, to
determine particle size; and UV-Vis spectroscopy, to determine particle
stability in a variety of media.