Gadolinium polytungstate nanoclusters: a new theranostic with ultrasmall size and versatile properties for dual-modal MR/CT imaging and photothermal therapy/radiotherapy of cancer

The development of a new generation of nanoscaled theranostics with simple compositions and versatile properties to realize enhanced diagnoses and treatment outcomes and to avoid side effects is highly desirable but remains a great challenge. Here we report a new ultrasmall theranostic based on bovine serum albumin-coated GdW10O36 nanoclusters (GdW10NCs) as multifunctional theranostics for multifunctional bio-imaging, highly effective in vitro photothermal ablation of cancer cells and in vivo radiotherapy of tumors. The as-synthesized GdW10 NCs afford significantly enhanced computed tomography/magnetic resonance imaging signals and remarkable photothermal therapy (PTT)/radiotherapy therapy (RT) therapeutic effects for tumor treatment. Moreover, toxicity studies confirmed their low toxicity and efficient renal clearance, suggesting their potential for practical applications. These results indicated that the as-prepared GdW10 nanoclusters are promising as multifunctional nanotheranostics for multimodal imaging-guided PTT/RT of tumors. These results also encourage the further exploration of other polyoxometalate-based multifunctional nanotheranostics for cancer diagnoses and therapy.