Manganese Dioxide-Based Nanomaterials for Medical Applications

Manganese dioxide (MnO₂) nanomaterials can react with trace hydrogen peroxide (H₂O₂) to produce paramagnetic manganese (Mn²⁺) and oxygen (O₂), which can be used for magnetic resonance imaging and alleviate the hypoxic environment of tumors, respectively. MnO₂ nanomaterials also can oxidize glutathione (GSH) to produce oxidized glutathione (GSSG) to break the balance of intracellular redox reactions. As a consequence of the sensitivity of the tumor microenvironment to MnO₂-based nanomaterials, these materials can be used as multifunctional diagnostic and therapeutic platforms for tumor imaging and treatment. Importantly, when MnO₂ nanomaterials are implanted along with other therapeutics, synergetic tumor therapy can be achieved. In addition to tumor treatment, MnO₂-based nanomaterials display promising prospects for tissue repair, organ protection, and the treatment of other diseases. Herein, we provide a thorough review of recent progress in the use of MnO₂-based nanomaterials for biomedical applications, which may be helpful for the design and clinical translation of next-generation MnO₂ nanomaterials.