Mesoporous silica-coated bismuth nanohybrids as a new platform for photoacoustic/computed tomography imaging and synergistic chemophotothermal therapy

Aim: Polyethylene glycol modified mesoporous silica-coated bismuth nanohybrids (Bi@mSiO₂-PEG) are fabricated for chemothermotherapy and multimodal imaging. Materials & methods: 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. Results: 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. Conclusion: These results reveal great potentials of the Bi@mSiO₂-PEG for precise and efficient anticancer treatments.