Development of tungsten bronze nanorods for redox-enhanced photoacoustic imaging-guided photothermal therapy of tumors

Although various kinds of nanomaterials have been used as anticancer theranostics by exploiting the tumor microenvironment, relatively few nanomaterials can be efficiently activated by the tumor redox status for imaging and therapy. Oxygen-deficient tungsten-based oxides or bronzes are appearing as new classes of near-infrared (NIR)-responsive nanomaterials due to their unique properties such as tunable and broad NIR absorption. Herein, we synthesized PEG-Na(x)WO(3) nanorods (NRs) by a simple thermal decomposition method and investigated their redox-activated performance for enhanced photoacoustic (PA) imaging and photothermal therapy (PTT) of cancers. Both in vitro and in vivo studies revealed that such a novel class of tungsten bronzes with low toxicity could be used as efficient photothermal agents for PA imaging-guided PTT of cancers.