Defect Engineering of 2D BiOCl Nanosheets for Photonic Tumor Ablation
Photothermal therapy (PTT) is an emerging alternative noninvasive therapeutic modality for photonic cancer hyperthermia. However, current photothermal-conversion agents suffer from low therapeutic efficiency and single functionality. Engineering crystal defects to the surface or substrate of semiconductors can substantially enhance their optical-absorption ability and photothermal effect in theranostic nanomedicine. In this work, a specific defect-engineering strategy was developed to endow two-dimensional (2D) BiOCl nanosheets with intriguing photothermal-conversion performance by creating oxygen vacancies on the surface (O-BiOCl). Importantly, the photothermal performance and photoacoustic imaging capability of 2D O-BiOCl nanosheets could be precisely controlled by modulating the amounts of oxygen vacancies. The strong Bi-based X-ray attenuation coefficient endowed these nanosheets with the capability for contrast-enhanced computed tomography imaging. The high near infrared-triggered photonic hyperthermia for tumor ablation has been systematically demonstrated both in vitro at cellular level and in vivo on tumor breast-cancer mice xenograft. Based on the demonstrated high biocompatibility of 2D O-BiOCl nanosheets, this work not only constructs an intriguing 2D photothermal nanoagent for tumor ablation, but also provides an efficient strategy to control the photothermal performance of nanoagents by defect engineering.