Gold-nanobranched-shell based drug vehicles with ultrahigh photothermal efficiency for chemo-photothermal therapy

Development of combined chemo-photothermal nanoplatform is of great interest for enhancing antitumor efficacy. Herein, a multifunctional drug delivery system was synthesized based on gold-nanobranched coated betulinic acid liposomes (GNBS-BA-Lips) for chemo-photothermal synergistic therapy. In this system, GNBS-BA-Lips exhibited broad near-infrared (NIR) absorption, preferable photothermal response and good photostability under NIR irradiation. Importantly, the gold-nanobranched nanostructure possessed high photothermal conversion efficiency (η = 55.7%), and the temperature change (ΔT) reached 43.2 °C after laser irradiation for 5 min. Upon NIR irradiation, the nanocarriers apparently endowed higher cell uptake, resulting in an enhanced intracellular drug accumulation. Furthermore, the tumor growth inhibition ratio achieved from chemo-photothermal therapy of GNBS-BA-Lips was 86.9 ± 1.1%, which was higher than that of the chemotherapy or photothermal therapy alone, showing an outstanding synergistic anticancer effect. Our data suggested that the nanoplatform should be considered as a critical platform in the development of cancer multi-mode therapies. A natural compound, betulinic acid (BA), was encapsulated in the liposomes and gold-nanobranched shell coated betulinic acid liposomes (GNBS-BA-Lips) were fabricated through a facile, controllable and surfactant-free approach. The drug delivery system possessed preferable NIR light responsivity, can rapidly realize the transformation of light-to-heat and control the on-demand drug release upon NIR laser irradiation. The GNBS-BA-Lips also exhibited superior photothermal stability, ultrahigh photothermal efficiency, and markedly synergistic effect of chemo-photothermal treatment. [Display omitted]