Scheme 1

Schematic illustration of the preparation of TMVP1-ICG-NPs and targeted imaging and PTT/PDT based on TMVP1-ICG-NP. Maleimide bond-terminated PEG (Mal-PEG) was chemically linked to PLGA to obtain Mal-PEG-PLGA, and peptide TMVP1 was connected to PEG-PLGA by reaction with the maleimide bond of PEG. Next, TMVP1-ICG-NPs were prepared by the nano-precipitation under magnetic stirring. Self-assembly occurred through hydrophobic forces of PLGA and the ICG was wrapped into the hydrophobic shell, while PEG, as a hydrophilic branch of the shell, enabled the nanoprobe to dissolve in water. The nanoprobe was actively targeted to new lymphatic vessels with tumor metastasis by binding to VEGFR-3 after tail vein injection. ICG was released by lysosome degradation, and then imaging, PTT, and PDT were performed under the irradiation of NIR.