Figure 14.

(A) Representation of the preparation process of MCOPP NE; (B) O₂ generation of MCOPP NE. The inset images show photographs of H₂O₂ solutions with and without MCOPP NE; (C) degradation of H₂O₂ with and without MCOPP NE. Cell viability of 4T1 cells treated in normoxic (D) and hypoxic (E) environments before and after 671 nm laser irradiation; (F) representative immunofluorescence images of tumor slices after hypoxia staining. The hypoxia areas and blood vessels were stained by anti-pimonidazole antibody (green) and anti-CD31 antibody (red); (G) relative hypoxia positive areas and blood vessel density measured by the Image J software; (H) relative tumor volume of mice after treatments (n = 5). Reprinted with permission from Wang D, Wu H, Lim WQ et al. A Mesoporous Nanoenzyme Derived from Metal-Organic Frameworks with Endogenous Oxygen Generation to Alleviate Tumor Hypoxia for Significantly Enhanced Photodynamic Therapy. Adv Mater. 2019;31(27):e1901893. Copyright (2019) WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.⁵⁷