EGFR-targeted photosensitizer for enhanced photodynamic therapy and imaging therapeutic effect by monitoring GSH decline

Chemotherapy (CMT) and photodynamic therapy (PDT) are dose-dependent treatments, and overdose of these treatment will destroy normal cells and cause serious side effects. Hence, it is urgent to monitor the therapeutic effects and exploit a more resultful and noninvasive treatment mode to alleviate side effects to normal tissues. Inspired by the design of molecular targeted drug and the GSH responsive function of copper(II) porphyrin, we have designed and synthesized a novel compound (E-CuTPP), in which a small molecular targeted drug (erlotinib) and a copper porphyrin(II) are conjugated. We demonstrated that E-CuTPP can exhibit higher toxicity towards epidermal growth factor receptor (EGFR) overexpressed cancer cells. Furthermore, E-CuTPP can monitor intracellular glutathione fluctuations, which is closely related to apoptosis. Upon treatment, the fluorescence of E-CuTPP will dramatically increase, which can timely estimate the therapeutic efficiency.