Manganese-Based Antioxidase-Inspired Biocatalysts with Axial Mn-N-5 Sites and 2D d-pi-Conjugated Networks for Rescuing Stem Cell Fate

Constructing highly effective biocatalysts with controllable coordination geometry for eliminating reactive oxygen species (ROS) to address the current bottlenecks in stem-cell-based therapeutics remains challenging. Herein, inspired by the coordination structure of manganese-based antioxidase, we report a manganese-coordinated polyphthalocyanine-based biocatalyst (Mn PcBC) with axial Mn N-5 sites and 2D d-pi-conjugated networks that serves as an artificial antioxidase to rescue stem cell fate. Owing to the unique chemical and electronic structures, Mn PcBC displays efficient, multifaceted, and robust ROS-scavenging activities, including elimination of H2O2 and O-2(center dot-). Consequently, Mn PcBC efficiently rescues the bioactivity and functionality of stem cells in high-ROS-level microenvironments by protecting the transcription of osteogenesis-related genes. This study offers essential insight into the crucial functions of axially coordinated Mn-N-5 sites in ROS scavenging and suggests new strategies to create efficient artificial antioxidases for stem-cell therapies.