Redox-Sensitive Folate-Conjugated Polymeric Nanoparticles for Combined Chemotherapy and Photothermal Therapy Against Breast Cancer

We have developed redox-sensitive folic acid-conjugated PCL-PEG-PCL (PCEP) nanoparticles for co-delivering chemotherapeutic agent doxorubicin (DOX) and imaging and hyperthermia agent indocyanine green (ICG) with simultaneous imaging and combined therapy for breast cancer. DOX and ICG were entrapped into PCEP nanoparticles through the thin-film hydration and ultrasonic dispersion. Then nanoparticles were surface decorated with folic acid ligands against FR overexpressing breast cancers. Drug-loading nanoparticles exhibited an enhanced reduction-sensitivity in the presence of 10 mM glutathione. Nanoparticle-mediated treatment had synergistic cytotoxicity against mammary cancer cells. The conjugation of folic acid improved the uptake of nanoparticles in EMT-6 breast cancer overexpressing cell lines, and the uptake efficacy of DOX was remarkably increased by the laser irradiation. Furthermore, ex vivo fluorescence imaging confirmed that folate conjugation also improved drug accumulation in tumor. Our unique FA-DINPs system has potential for combination of chemotherapy and photothermal therapy for breast cancer.