Bifunctional Gold Nanoshells with a Superparamagnetic Iron Oxide-Silica Core Suitable for Both MR Imaging and Photothermal Therapy.

Research paper by Xiaojun X Ji, Ruping R Shao, Andrew M AM Elliott, R Jason RJ Stafford, Emilio E Esparza-Coss, James A JA Bankson, Gan G Liang, Zhi-Ping Z Luo, Keeseong K Park, John T JT Markert, Chun C Li

Indexed on: 06 Apr '07Published on: 06 Apr '07Published in: Journal of Physical Chemistry C


We describe the synthesis, characterization, and use of hybrid nanoparticles with a superparamagnetic iron oxide (SPIO) core and a gold nanoshell. These multifunctional nanoparticles, designated SPIO-Au nanoshells, displayed superparamagnetic characteristics and a significant absorbance in the near-infrared (NIR) region of the electromagnetic spectrum. In addition, they exhibited high transverse relaxivity, r2 , and a large r2/r1 ratio and therefore could be imaged by MRI to obtain T2-weighted images. Moreover, SPIO-Au nanoshells showed efficient photo-thermal effect when exposed to NIR light. The use of SPIO-Au nanoshells, with their combination of unique magnetic and optical properties, should enhance the efficacy of nanoshell-mediated photo-thermal therapy by making it possible to direct more nanoparticles to tumors through the application of external magnetic field and by permitting real-time in vivo MRI imaging of the distribution of the nanoparticles before, during, and after photo-thermal therapy.