One-pot photoreduction to prepare NIR-absorbing plasmonic gold nanoparticles tethered by amphiphilic polypeptide copolymer for synergistic photothermal-chemotherapy

Abstract We developed one-pot photoreduction strategy to prepare near infrared light (NIR)-absorbing plasmonic gold nanoparticles (Au NPs) tethered by amphiphilic polypeptide copolymer poly( l -cysteine)- b -poly(ethylene oxide) (PLC- b -PEO). The PLC- b -PEO@Au NPs possessed strong NIR absorption at 700–1100 nm and ultrahigh photothermal conversion efficiency of 62.1%. Upon the NIR irradiation (808 nm, 2 W/cm 2 , 5 min), the PLC- b -PEO@Au NPs (1 mg/mL) sharply attained an elevation of 30.8 °C and the hyperthermia effect could efficiently kill cancer cells in vitro . As for the PT-CT treatment, the doxorubicin (DOX)-loaded nanoparticles of DOX-PLC- b -PEO@Au NPs gave a combination index of 0.9 compared to single chemotherapy (CT) or photothermal therapy (PT), demonstrating a synergistic effect.