Mesoporous Silica-Coated Bismuth Nanohybrids as a New Platform for Photoacoustic/Computed Tomography Imaging and Synergistic Chemophotothermal Therapy

Polyethylene glycol modified mesoporous silica-coated bismuth nanohybrids (Bi@mSiO2-PEG) are fabricated for chemothermotherapy and multimodal imaging.The Bi@mSiO2-PEG are synthesized by coating mesoporous SiO2 onto metallic Bi cores, followed by PEG modification. Their cytotoxicity, photothermal effect, drug loading, antitumor effect and imaging abilities are evaluated.The nanohybrids show good biocompatibility, strong near-infrared absorbance, high photothermal conversion efficiency (∼36.6%), prominent infrared thermal imaging and photothermal killing efficacy on cancer cells. Utilizing the nanohybrids as potent drug carriers, a synergistic antitumor effect through chemothermotherapy is realized. Thanks to the superhigh x-ray attenuation coefficient and strong photothermal ability, high-contrast photoacoustic and x-ray computed tomography imaging are achieved.These results reveal great potentials of the Bi@mSiO2-PEG for precise and efficient anticancer treatments.