FDPP-HA as a theranostic agent for cancer-targeted fluorescence imaging and photodynamic therapy

In clinics, for photodynamic therapy (PDT) it is challenging to achieve photosensitizers with properties of high singlet oxygen quantum yield, tumor targeting and fluorescence imaging simultaneously. Herein, a furan flanked diketopyrrolopyrrole (FDPP) molecule, with good singlet oxygen quantum yield (∼26%), is covalently connected to hyaluronic acid (HA) to obtain a water-soluble photosensitizer (FDPP-HA), which presents good specific targeting to HCT-116 tumor cells both in vitro and in vivo. FDPP-HA also exhibits excellent biocompatibility, low dark toxicity and high phototoxicity, which can effectively inhibit the tumor growth in vivo by PDT. The design of FDPP-HA in this work provides a general strategy for cancer target-specific fluorescence imaging and PDT.