NIR driven catalytic enhanced acute lung injury therapy by using polydopamine@Co nanozyme via scavenging ROS

Acute lung injury (ALI) was characterized by excessive reactive oxygen species (ROS) levels and inflammatory response in the lung. Scavenging ROS could inhibit the excessive inflammatory response, further treating ALI. Herein, we designed a novel nanozyme (P@Co) comprised of polydopamine (PDA) nanoparticles (NPs) loading with ultra-small Co, combining with near infrared (NIR) irradiation, which could efficiently scavenge intracellular ROS and suppress inflammatory responses against ALI. For lipopolysaccharide (LPS) induced macrophages, P@Co + NIR presented excellent antioxidant and anti-inflammatory capacities through lowering intracellular ROS levels, decreasing the expression levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) as well as inducing macrophage M2 directional polarization. Significantly, it displayed the outstanding activities of lowering acute lung inflammation, relieving diffuse alveolar damage, and up-regulating heat shock protein 70 (HSP70) expression, resulting in synergistic enhanced ALI therapy effect. It offers a novel strategy for the clinical treatment of ROS related diseases.