Pd nanoparticle-decorated hydroxy boron nitride nanosheets as a novel drug carrier for chemo-photothermal therapy.

A multi-stimuli responsive nanoagent, hydroxy boron nitride nanosheets and Pd nanohybrids (Pd@OH-BNNS), was studied. The well-dispersed hydroxy boron nitride nanosheets were prepared via a facile thermal substitution approach. Pd@OH-BNNS was endowed with a photothermal property after in situ formation of Pd nanoparticles on the surface of the nanosheets. Pd@OH-BNNS as a drug delivery carrier exhibited high loading capability for the anticancer drug doxorubicin. The release of doxorubicin from the nanohybrids was triggered by a decrease in pH, and increases in glutathione concentration and near-infrared irradiation. The faster release behavior of the nanohybrids under near-infrared irradiation was confirmed by a cellular uptake study. In addition, local hyperthermia was verified using an imaging test and an infrared thermal camera. Tumor growth was remarkably inhibited in mice after two weeks of treatment with Pd@OH-BNNS/doxorubicin injection, demonstrating the high efficacy of combining chemotherapy and photothermal therapy. The Pd@OH-BNNS as a drug delivery system exhibited good stability, low cytotoxicity and multi-stimuli responsiveness.