Enhanced Cancer Imaging and Chemo-Photothermal Combination Therapy by Cancer-Targeting Bismuth-Based Nanoparticles

Due to the complexity and heterogeneity of cancer, the clear and accurate tumor imaging and image-guided multimodal synergistic therapy are highly in demand. Here, bismuth (Bi)-based mesoporous-silica-coated nanoparticles (BMSNs) are successfully fabricated with the silica shell thickness being lower than the Bi nanoparticle diameter. Then, an MCF-7 breast cancer-targeting peptide (termed AR) is modified onto the surface of BMSNs. The obtained nanoparticles (BMSN-AR) show a significantly higher loading of doxorubicin hydrochloride (DOX). The resultant BMSN-AR-DOX can agglomerate in the tumor site, enabling enhanced computed tomography (CT) imaging of the whole tumor. Under 808 nm near-infrared (NIR) laser irradiation, the BMSN-AR-DOX also effectively converts light energy into thermal energy to achieve synergistic chemo-photothermal therapy in vivo. The chemo-photothermal combination therapy is found to be more effective than chemotherapy or photothermal therapy alone. This work demonstrates that tumor-homing peptides can guide nanoparticles to tumors and allow the nanoparticles to enhance cancer imaging and photothermal/chemo combination therapy.