Waste tobacco leaf-driven carbon dot nanozymes with high reactive oxygen species scavenging and anti-inflammatory activities for the amelioration of acute lung injury

Considering the important role of tobacco in promoting the economic development of agricultural crops, the high-value recycling of its waste has been a hot topic of interest. In this study, we developed a waste tobacco leaf-driven biomass-based carbon dot (Cur@TB CD) nanozyme with high reactive oxygen species (ROS) scavenging and anti-inflammatory activities for the amelioration of acute lung injury (ALI) both in vitro and in vivo . The results showed that the Cur@TB CD manifested good superoxide dismutase (SOD)-like activity and hydroxyl radical (•OH) scavenging ability, making them impressive scavengers of ROS. Moreover, the intracellular analysis of the Cur@TB CD revealed that Cur@TB CD could spontaneously enter the cells via endocytosis and was distributed mainly in the organelles of lysosomes and mitochondria. As a result, intracellular endogenous ROS can be scavenged to inhibit the expression of proinflammatory cytokines ( e.g. , TNF-α, IL-6, and IL-1β), alleviating inflammation in lipopolysaccharide (LPS)-induced ALI in vivo . Importantly, as a biomass-derived product, Cur@TB CD exhibited negligible side effects and acceptable biosafety in vivo , suggesting promising application potential for curing and preventing ALI in clinical applications, with easy-to-prepare, economical, green and environmentally friendly methods.