Dual-Modal Imaging-Guided Theranostic Nanocarriers Based on Indocyanine Green and mTOR Inhibitor Rapamycin

The development of treatment protocols that resulted in a complete response to photothermal therapy (PTT) was usually hampered by uneven heat distribution and low effectiveness. Here, we reported an NIR fluorescence and photoacoustic dual-modal imaging-guided active targeted thermal sensitive liposomes (TSLs) based on the photothermal therapy agent Indocyanine green (ICG) and antiangiogenesis agent Rapamycin (RAPA) to realize enhanced therapeutic and diagnostic functions. As expected, the in vitro drug release studies exhibited the satisfactory result of drug released from the TSLs under hyperthermia conditions induced by NIR stimulation. The in vitro cellular studies confirmed that the FA-ICG/RAPA-TSLs plus NIR laser exhibited efficient drug accumulation and cytotoxicity in tumor cells and epithelial cells. After 24 h intravenous injection of FA-ICG/RAPA-TSLs, the margins of tumor and normal tissue were accurately identified via the in vivo NIR fluorescence and photoacoustic dual-modal imaging. In addition, FA-ICG/RAPA-TSLs combined with NIR irradiation treated tumor-bearing nude mice inhibited tumor growth to a great extent and possessed much lower side effects to normal organs. All detailed evidence suggested that the theranostic TSLs which were capable of enhancing the therapeutic index might be a suitable drug delivery system for dual-modal imaging-guided therapeutic tools for diagnostics as well as the treatment of tumors.