Folic acid-modified Fe3O4@Au core/shell nanostars for multimode imaging and photothermal therapy of tumors

Abstract

Event Abstract Back to Event Folic acid-modified Fe3O4@Au core/shell nanostars for multimode imaging and photothermal therapy of tumors Xiangyang Shi1, Yong Hu1, Ruizhi Wang2 and Mingwu Shen1 1 Donghua University, College of Chemistry, Chemical Engineering and Biotechnology, China 2 Zhongshan Hospital, Fudan University,, Interventional Radiography, China Iron oxide (Fe3O4) nanoparticles (NPs) have been generally used as T2-negative magnetic resonance (MR) imaging contrast agents because of their ability to shorten the T2 relaxation time of water protons[1]. On the other hand, gold (Au) NPs have been widely used as CT imaging contrast agents due to their high X-ray attenuation coefficient[2]. In addition, AuNPs with particular shapes such as nanorods, nanocages, or nanostars (NSs) display strong surface plasmon resonance (SPR) absorption in near infrared (NIR) region, enabling their uses for photoacoustic (PA) imaging, thermal imaging and photothermal therapy of cancer[3],[4]. In this work, a facile mild reduction method was employed to synthesize Fe3O4@Ag nanoparticles (NPs)[1] and the thus-prepared NPs were used as seeds to form Fe3O4@Au NSs in the Au growth solution. Further sequential modification of polyethyleneimine (PEI) and folic acid (FA)-conjugated polyethylene glycol (PEG-FA) affords the NSs with excellent colloidal stability, good biocompatibility, and targeting specificity to cancer cells over-expressing FA receptors. With the Fe3O4 core NPs and the star-shaped Au shells, the formed Fe3O4@Au-PEI.Ac-PEG-FA NSs are able to be used as a nanoprobe for efficient of MR and computed tomography (CT) imaging of cancer cells in vitro and the xenografted tumor model in vivo. Likewise, the NIR absorption property enables the developed Fe3O4@Au-PEI.Ac-PEG-FA NSs to be used as a nanoprobe for PA and thermal imaging of tumors in vivo and photothermal ablation of cancer cells in vitro and the xenografted tumor model in vivo. This study fully demonstrates a unique multifunctional theranostic nanoplatform for multimode imaging and photothermal therapy of tumors. National Natural Science Foundation of China (21273032, 81341050, and 81371623); Sino-German Center for Research Promotion (GZ899); Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning; Fundamental Research Funds for the Central Universities; Innovation Funds of Donghua University Master Dissertation of Excellence