A cancer-recognizing polymeric photosensitizer based on the tumor extracellular pH response of conjugated polymers for targeted cancer photodynamic therapy.

Herein, a cancer-recognizing polymeric photosensitizer (CRPP) was demonstrated not only for high water solubility but also for pH-responsive targeted photodynamic cancer therapy. The synthesized CRPP exhibited high water solubility and the pH-dependent charge-switching property. From an in vitro cellular internalization study with HCT-116 human colon cancer cells, significantly enhanced cellular uptake as detected for CRPP at pH 6.5 compared to the cellular uptake of CRPP at pH 7.4, which led to enhanced cytotoxicity in the cancer cells. Finally, the CRPP was found to exhibit high tumor-targeting efficacy in an in vivo tumor model and was finally excreted through the renal route.