Engineering of tungsten carbide nanoparticles for imaging-guided single 1,064 nm laser-activated dual-type photodynamic and photothermal therapy of cancer

Abstract

The promising potential of photodynamic therapy (PDT) has fueled the development of minimally invasive therapeutic approaches for cancer therapy. However, overcoming limitations in PDT efficacy in the hypoxic tumor environment and light penetration depth remains a challenge. We report the engineering of tungsten carbide nanoparticles (W2C NPs) for 1,064 nm laser-activated dual-type PDT and combined theranostics. The synthesized W2C NPs allow the robust generation of dual-type reactive oxygen species, including hydroxyl radicals (type I) and singlet oxygen (type II), using only single 1,064 nm laser activation, enabling effective PDT even in the hypoxic tumor environment. The W2C NPs also possess high photothermal performance under 1,064 nm laser irradiation, thus enabling synergistically enhanced cancer therapeutic efficacy of PDT and photothermal therapy. Additionally, the photoacoustic and X-ray computed tomography bioimaging properties of W2C NPs facilitate the integration of tumor diagnosis and therapy. The developed W2C based theranostic nanoagents increase the generation of reactive oxygen species in hypoxic tumors, improve the light penetration depth, and facilitate combined photothermal therapy and photoacoustic/computed tomography dual-mode bioimaging. These attributes could spur the exploration of transition metal carbides for advanced biomedical applications.