Octopod PtCu Nanoframe for Dual-Modal Imaging-Guided Synergistic Photothermal Radiotherapy

Abstract

Heavy atom nanoparticles have high X-ray absorption capacity and near infrared (NIR) photothermal conversion efficiency, which could be used as radio-sensitizers. We hypothesized that concave PtCu octopod nanoframes (OPCNs) would be an efficient nanoplatform for synergistic radio-photothermal tumor ablation. <b>Methods:</b> In this study, we newly exploited a folic acid-receptor (FR) mediated photothermal radiotherapy nanoagent base on OPCNs. OPCNs were synthesized with a hydrothermal method and then modified with polyethylene glycol (PEG) and folic acid (FA). A series of physical and chemical characterizations, cytotoxicity, targeting potential, endocytosis mechanism, biodistribution, systematic toxicological evaluation, pharmacokinetics, applications of OPCNs-PEG-FA for <i>in vitro</i> and <i>in vivo</i> infrared thermal imaging (ITI)/photoacoustic imaging (PAI) dual-modal imaging and synergistic photothermal radiotherapy against tumor were carried out. <b>Results:</b> The OPCNs-PEG-FA demonstrated good biocompatibility, strong NIR absorption and X-ray radio-sensitization, which enabling it to track and visualize tumor <i>in vivo</i> via ITI/PAI dual-modal imaging. Moreover, the as-synthesized OPCNs-PEG-FA exhibited remarkable photothermal therapy (PTT) and radiotherapy (RT) synergistic tumor inhibition when treated with NIR laser and X-ray. <b>Conclusion:</b> A novel multifunctional theranostic nanoplatform based on OPCNs was designed and developed for dual-modal image-guided synergistic tumor photothermal radiotherapy.