Manganese Dioxide-Based Nanomaterials for Medical Applications

Manganese dioxide (MnO 2 ) nanomaterials can react with trace hydrogen peroxide (H 2 O 2 ) to produce paramagnetic manganese (Mn 2+ ) and oxygen (O 2 ), which can be used for magnetic resonance imaging and alleviate the hypoxic environment of tumors, respectively. MnO 2 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 MnO 2 -based nanomaterials, these materials can be used as multifunctional diagnostic and therapeutic platforms for tumor imaging and treatment. Importantly, when MnO 2 nanomaterials are implanted along with other therapeutics, synergetic tumor therapy can be achieved. In addition to tumor treatment, MnO 2 -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 MnO 2 -based nanomaterials for biomedical applications, which may be helpful for the design and clinical translation of next-generation MnO 2 nanomaterials.