Tumor microenvironment-oriented MOFs for chemodynamic therapy

Non-invasive tumor therapy via in situ ROS generation is emerging as an appealing treatment modality with the potential for deep-seated tumors without side effects on healthy tissue. Chemodynamic therapy (CDT) based on Fenton/Fenton-like reactions is a non-invasive cancer treatment, which converts hydrogen peroxide (H2O2) found locally into lethal hydroxyl radicals (OH) through the exploitation of transition metal ions as catalysts in an acidic tumor microenvironment (TME) suitable for effective oncotherapy. Metal-organic frameworks (MOFs) exhibit great promise for CDT on account of their unique properties. Among them, the stimuli-responsive nature and the porosity of MOFs make them ideal for TME-targeted cargo delivery. In addition, the ability to select appropriate metal ions and organic ligands makes it possible to prepare MOFs with intrinsic antitumor activity. This review primarily summarizes the latest progress in the application of tumor microenvironment-oriented MOFs for CDT, including MOFs without or with intrinsic chemodynamic activity. Furthermore, the remaining challenges and suggestions for future applications of MOFs for CDT are also presented.