A chemo/photo- co-therapeutic system for enhanced multidrug resistant cancer treatment using multifunctional mesoporous carbon nanoparticles coated with poly (curcumin-dithiodipropionic acid)

It is still a tremendous challenge to combat multidrug resistant (MDR) cancer up to now, due to cancer resistance to chemotherapeutic agents. Herein, we put a new strategy for effective treatment of MDR cancer by improving chemotherapeutic efficacy via chemosensitizer in combination with phototherapy. Our previous work has demonstrated poly (ethylene glycol) - poly (curcumin-dithiodipropionic acid) (PEG-PCDA) is a good pre-chemosensitizer and enhances the sensitivity of MDR cancer cells to doxorubicin (DOX). In this study, we firstly synthesized mesoporous carbon nanoparticles (MCNs) having excellent photothermal and photodynamic effects, which could load a high dose of hydrophobic drug and presented pH -responsive drug release characteristics. On this basis, we developed a multifunctional MCN based drug delivery system to take chemo/photo- co-therapy against MDR human breast cancer MCF-7/ADR cells. The MCN based drug delivery system loaded 36.4% DOX and was coated with 23.2% PEG-PCDA, which could take photothermal and photodynamic effects under near-infrared (NIR) irradiation and trigger drug release by pH, glutathione (GSH), and/or NIR irradiation, termed as PEG-PCDA/DOX@MCNs. Once the PEG-PCDA/DOX@MCNs had been delivered into MCF-7/ADR cells, DOX release was triggered by degradation of PEG-PCDA via GSH and weak acidic pH, and in combination with MCN yielded photothermal and photodynamic effects under NIR irradiation, PEG-PCDA/DOX@MCNs could reduce premature drug release and then enhance anti-MDR cancer efficacy.