Nanocatalytic Therapy for Pneumonia by a Hetero-Element-Doped Carbon Nanozyme

Pneumonia continues to be complicated by its progression to acute lung injury (ALI). The onset of ALI is linked to an overproduction of reactive oxygen species (ROS) and a severe inflammatory response. Therefore, the rapid mitigation of ROS and inflammation is crucial in addressing ALI. Concurrently, prompt bacterial elimination is necessary for bacteria-induced ALI. Here, a Co-based carbon nanozyme (CN) with enhanced enzyme-like activities is developed by co-doping with a small amount of Mn (CoMn CN). Compared to cobalt CN without Mn co-doping (Co CN), the active sites of Co and its coordination with N in CoMn CN are slightly altered, resulting in enhanced oxidase (OXD)-, peroxidase (POD)-, superoxide dismutase (SOD)-, and catalase (CAT)-like activities. Given the enhanced enzyme-like activities, its applications for lipopolysaccharide (LPS)- and methicillin-resistant Staphylococcus aureus (MRSA)-induced ALI treatments are explored. CoMn CN demonstrates superior efficacy in both LPS- and MRSA-induced ALI models, effectively combining rapid scavenging of ROS and inflammation with subsequently bacterial elimination. Consequently, a novel type of Co-based CN by Mn co-doping is developed to augment enzyme-like activities, offering significant protective effects against ALI. This study not only broadens the application of Co-based CNs but also shows a promising strategy for ALI therapy.