Gold Nanorods Functionalized with Cathepsin B Targeting Peptide and Doxorubicin for Combinatorial Therapy against Multidrug Resistance

Multidrug resistance (MDR) and adverse effects of chemotherapeutic agents are severe issues in clinical cancer treatment. Due to the dysregulation of enzymes in the cancer cells, enzyme-responsive drug delivery systems (DDSs) have been considered as a viable technology for cancer chemotherapy. In the present work, doxorubicin (DOX) is visible after leaving from AuNR–LAX. After treatment with AuNR–LAX, the drug resistance index of DOX-resistant MCF-7/ADR cells was reduced from extremely high 955.0 to 1.7, implying high potential of AuNR–LAX in the MDR phenotype cancer treatment. In addition, the cellular viability of both MCF-7 and MCF-7/ADR cells decreased from 50% to 80% after treatment with AuNR–LAX along (equivalent DOX concentration = 2.3 μg/mL, Au concentration = 30 μg/mL) to below 10% after AuNR–LAX treatment plus radiation of 808 nm, due to the NIR photothermal effect of AuNRs. Human bronchial epithelial cell line 16HBE was chosen to evaluate the adverse effect of AuNR–LAX on the normal cells. At t...