Theranostic Nanomedicine Carrying L-Menthol and Near-Infrared Dye for Multimodal Imaging-Guided Photothermal Therapy of Cancer.

Photothermal therapy (PTT) as an emerging technique for cancer treatment has drawn great attention owing to its minimally invasive nature. However, it is difficult to achieve a complete tumor regression due to the heterogeneous heat distribution over the tumor. Application of photothermal conversion agents may enhance PTT efficiency, and a multifunctional imaging may provide guidance for the implementation of PTT. Herein, an L-menthol/IR-780 loaded liposome (MIL) is prepared to achieve NIR-triggered cavitation for enhancing photothermal ablation. The synthesized MIL possesses outstanding colloidal stability and photoacoustic/near infrared fluorescence/ultrasound (PA/NIRF/US) imaging contrast to offer multimodal imaging-guided photothermal therapy of cancer. Upon irradiation, the IR-780 acts as the photoabsorber to convert NIR light into heat energy. More importantly, the produced hyperthermia can not only induce ablation of tumor cells but also trigger vaporization and bubbling of encapsulated L-menthol (menthol). Consequently, the generated menthol bubbles obviously enhance the US imaging signal and promote photothermal ablation of the tumor.