Antioxidase‐Like Nanobiocatalysts with Ultrafast and Reversible Redox‐Centers to Secure Stem Cells and Periodontal Tissues

Abstract Exploration of efficient antioxidase‐like reactive oxygen nanobiocatalysts (ROBCs) is a major challenge in combating oxidative stress‐related diseases. Herein, the molecularly well‐defined Ru‐porphyrin‐networks (Ru‐Por‐Net)‐based ROBCs with ultrafast and reversible redox‐centers for catalytic elimination of reactive oxygen species (ROS) are reported. Owing to the large π‐conjugated networks, Ru–N coordination structures, and unique electronic and redox properties of atomic Ru sites, the Ru‐Por‐Net‐based ROBCs exhibit exceptional catalytic ROS‐scavenging activities. It is considerably more efficient than recently reported state‐of‐the‐art anti‐ROS biocatalysts. Notably, a new nucleophilic attack pathway to eliminate H 2 O 2 and produce O 2 is proposed via theoretical calculations, and the desorption of the OO* process is identified as the rate‐determining step of atomic Ru centers. Cellular studies reveal that the new ROBCs can efficiently secure the survival, adhesion, spreading, and differentiation of the stem cells in high‐ROS‐level microenvironments. In vivo rat periodontitis treatments further demonstrate their superior anti‐ROS therapeutic effects. This study provides significant insights into the crucial functions of Ru–N coordinated porphyrin‐networks in catalytic ROS‐scavenging and offers a new strategy to engineer high‐performance antioxidase‐like nanobiocatalysts for stem cell‐based therapies and inflammatory diseases.