Figure 3. In vivo detoxifying capability of the catalase-containing enzyme nanocomplexes.

a, Cell viability assays after treated with n(GOx), mixture of n(GOx) and n(Cat), and n(GOx-Cat). Cell proliferation rates were normalized with those of the untreated cells. Cell viability assays were performed by incubating the treated cells with CellTiter Blue for 3 h at 37 °C. b, H₂O₂ concentration in glucose oxidation reaction catalysed by n(GOx), n(GOx)+n(Cat) or n(GOx-Cat). Enzyme reactions were performed in 1× phosphate buffer saline (PBS) and the initial concentration of glucose is 2 mg mL⁻¹. The system with n(GOx), the mixture of n(GOx) and n(Cat), and n(GOx–Cat) show rates of 0.434±0.004 μMmin⁻¹, 0.388± 0.005 μMmin⁻¹, and 0.075± 0.007 μMmin⁻¹, respectively. c, Photograph of a mouse cutaneously injected with PBS, n(Cat), H₂O₂, n(GOx) and n(GOx–Cat) at different sites. d, Micrographs of mouse skin tissue at the injection sites. Skin tissue was collected from the animal shown in c. Top and middle: H&E stained images. Bottom: Immunohistology stain with TUNEL assay (green), Cy3-conjugated monoclonal α-smooth muscle actin antibody (red) and DAPI (blue). Scale bars, 100 μm. Data represent mean±s.e.m. from three independent experiments.