IR783 Encapsulated in TR-Conjugated Liposomes for Enhancing NIR Imaging-Guided Photothermal and Photodynamic Therapy**

Abstract

An integrin αvβ3-specific liposomes (TR-LPs) were designed for loading IR783 to enhance NIR imaging-guided photothermal and photodynamic therapy (PTT and PDT). TR-LPs was composed of soyabean phosphatidylcholine, cholesterol, DSPE-PEG, and TR-functionalized DSPE-PEG. IR783, NIR photo-diagnostic agents, were encapsulated in the hydrophilic core of the TR-LPs. DSPE-PEG had ability of reducing the absorption of TR-LPs by the reticuloendothelial system and increase the cycle time in body. RGD fragment on the TR peptide enhanced the tumor selectivity of liposomes by specifically targeting integrin αvβ3-overexpressing cancer cells. Simultaneously, the rest of fragment on the TR peptide can be changed to the positive charge in the tumor microenvironment (pH 6.5), improving cellular uptake of the nanophotoagents. TR-LPs exhibited favorable physical and chemical stability, loading capacity, biocompatibility and tumor targeting in vitro and in vivo. IR783-TR-LPs is promising as a potentially safe and effective phototherapeutic agents for NIR fluorescence-guided tumor therapy applications.