Hollow mesoporous carbon nanospheres for imaging-guided light-activated synergistic thermo-chemotherapy

Carbon-based light-activated materials can absorb optical energy to generate photoacoustic (PA) signals for imaging or transduce optical photons to thermal energy, which holds great promise for biomedical applications. Herein, we synthesize hollow and mesoporous carbon nanospheres (HMCNs) with uniform size on a large scale. The properties of hollow cavity and mesoporous structures make the HMCNs achieve high drug loading (480 mg DOX per g HMCNs). The present intense near infrared (NIR) absorbance achieves excellent photoacoustic imaging ability and photothermal conversion efficacy (32.0%). More interestingly, the encapsulated drugs can have a triggered release under NIR irradiation. The investigations in vitro and in vivo demonstrate that HMCNs have excellent biocompatibility, and accumulate in tumors by the enhanced permeability and retention (EPR) effect. Moreover, under NIR irradiation, in vivo evaluation shows that HMCNs can perform strong PA imaging, and induce great tumor inhibition by the combination of chemotherapy and PTT under the guidance of photoacoustic imaging. The present study provides new insight for design of novel biocompatible light-activated carbons for cancer nanotheranostics.