Hybrid gold-iron oxide nanoparticles as a multifunctional platform for biomedical application.
BACKGROUND
Iron oxide nanoparticles (IONPs) have increasing applications in biomedicine, however fears over long term stability of polymer coated particles have arisen. Gold coating IONPs results in particles of increased stability and robustness. The unique properties of both the iron oxide (magnetic) and gold (surface plasmon resonance) result in a multimodal platform for use as MRI contrast agents and as a nano-heater.


RESULTS
Here we synthesize IONPs of core diameter 30 nm and gold coat using the seeding method with a poly(ethylenimine) intermediate layer. The final particles were coated in poly(ethylene glycol) to ensure biocompatibility and increase retention times in vivo. The particle coating was monitored using FTIR, PCS, UV-vis absorption, TEM, and EDX. The particles appeared to have little cytotoxic effect when incubated with A375M cells. The resultant hybrid nanoparticles (HNPs) possessed a maximal absorbance at 600 nm. After laser irradiation in agar phantom a ΔT of 32°C was achieved after only 90 s exposure (50 μg mL-1). The HNPs appeared to decrease T2 values in line with previously clinically used MRI contrast agent Feridex(®).


CONCLUSIONS
The data highlights the potential of these HNPs as dual function MRI contrast agents and nano-heaters for therapies such as cellular hyperthermia or thermo-responsive drug delivery.
Institute for Medical Science and Technology, University of Dundee, UK.
Clare
C
Hoskins
Yue
Y
Min
Mariana
M
Gueorguieva
Craig
C
McDougall
Alexander
A
Volovick
Paul
P
Prentice
Zhigang
Z
Wang
Andreas
A
Melzer
Alfred
A
Cuschieri
Lijun
L
Wang
D020811:Biomedical Technology / Q000379:methods*; D002450:Cell Communication; D045744:Cell Line, Tumor; D005290:Ferric Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006979:Hyperthermia, Induced; D007834:Lasers; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D013052:Spectrometry, X-Ray Emission; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide; D006046:Gold