Engineering Lung-Adaptive Nanozymes for Drug-Resistant and Biofilm-Associated Bacterial Pneumonia

Bacterial pneumonia represents a major global health burden, particularly in children, the elderly, and immunocompromised patients, and is increasingly complicated by multidrug-resistant pathogens and biofilm-protected infections. The central scientific problem is the imbalance between host defense and pathogen invasion, together with the lack of effective, trackable therapies that overcome resistance and penetrate pulmonary lesions. This review focuses on nanozymes that integrate nanomaterial architectures with enzyme-like catalytic activity as emerging platforms for the diagnosis and treatment of bacterial pneumonia. It summarizes design principles for peroxidase-, oxidase-, catalase-, and superoxide dismutase-like nanozymes, strategies for engineering lung-adapted and targeted delivery systems, and mechanisms by which nanozymes generate reactive oxygen species (ROS), disrupt bacterial cells and biofilms, and modulate inflammation. Recent theranostic applications, including systems that integrate antimicrobial activity with magnetic resonance, optical, or multimodal imaging, are discussed to illustrate their utility for infection-site visualization and treatment response assessment. By outlining key structure–activity relationships, biological barriers such as the lung mucosal layer, and current challenges in achieving high catalytic efficiency and bacterial selectivity in vivo, this review provides a framework for advancing nanozyme-based platforms toward clinical translation in bacterial pneumonia.