Multifunctional FePt–Au heterodimers: promising nanotheranostic agents for dual-modality MR/CT imaging diagnosis and in situ cancer therapy

Abstract

We report the synthesis of multifunctional FePt–Au hybrid nanoparticles via a simple hydrothermal approach and their potential application in cancer dual-modality MR/CT imaging diagnosis and simultaneous in situ therapy. After conjugation with meso-2,3-dimercaptosuccinic acid (DMSA) and SH–PEG–FA, the FePt–Au HNPs present high biostability in physiological solutions and successfully target folate acid (FA) receptor-positive cancer cells such as MCF-7, HeLa and HepG2. As a pH-sensitive agent, the as-prepared FePt–Au–DMSA/PEG–FA HNPs exhibit high cytotoxicity to the targeted cancer cells due to the generation of many reactive oxygen species (ROS) induced by the released Fe within the cells. The corresponding half-maximum inhibitory concentration value (IC50, Fe) is about 3.0 μg mL⁻¹. MR images and CT scans in vitro and in vivo demonstrate that the HNPs hold great potential as a dual-modality MR/CT imaging contrast agent for high-accuracy early-stage diagnosis of cancer. In addition, in vivo anti-tumor and histological studies indicate that the tumor growth is significantly inhibited after treating with HNPs with no observable toxicity found in the other tissues. Therefore, the FePt–Au–DMSA/PEG–FA HNPs are a promising multifunctional nanotheranostic agent for dual-modality MR/CT imaging diagnosis and in situ cancer therapy.