A GdW₁₀@PDA-CAT Sensitizer with High-Z Effect and Self-Supplied Oxygen for Hypoxic-Tumor Radiotherapy

Anticancer treatment is largely affected by the hypoxic tumor microenvironment (TME), which causes the resistance of the tumor to radiotherapy. Combining radiosensitizer compounds and O₂ self-enriched moieties is an emerging strategy in hypoxic-tumor treatments. Herein, we engineered GdW₁₀@PDA-CAT (K₃Na₄H₂GdW₁₀O₃₆·2H₂O, GdW₁₀, polydopamine, PDA, catalase, CAT) composites as a radiosensitizer for the TME-manipulated enhancement of radiotherapy. In the composites, Gd (Z = 64) and W (Z = 74), as the high Z elements, make X-ray gather in tumor cells, thereby enhancing DNA damage induced by radiation. CAT can convert H₂O₂ to O₂ and H₂O to enhance the X-ray effect under hypoxic TME. CAT and PDA modification enhances the biocompatibility of the composites. Our results showed that GdW₁₀@PDA-CAT composites increased the efficiency of radiotherapy in HT29 cells in culture. This polyoxometalates and O₂ self-supplement composites provide a promising radiosensitizer for the radiotherapy field.