Hemoglobin assisted one-pot synthesis of MnO2 nanozyme for radiation protection

The ongoing development of nuclear technologies, especially in medical diagnosis, calls for attention to radiation protection. Herein, a MnO 2 nanozyme with peroxidase activity was synthesized using hemoglobin (HGB) as the reducing agent and with a facile one-method method. The HGB-MnO 2 nanozyme showed good dispersity and near spherical morphology with size of about 5  nm . In addition, the HGB-MnO 2 nanozyme showed high colloidal stability and decent scavenging ability on different radicals (DPPH, ABST, hydroxyl, and superoxide radicals). Therefore, the HGB-MnO 2 nanozyme can effectively lower the intracellular ROS level, reduce the DNA damage and maintain the cell viability of HUVECs under X-ray irradiation. The in vivo experiments using C57BL/6J mice as the model also revealed a longer survival time in HGB-MnO 2 nanozyme treated group under X-ray radiation without causing observable damage to the subjects. Therefore, HGB-MnO 2 nanozyme can be considered as an effective and safe formulation for radiation protection.