Carbon dots derived from citric acid and glutathione as a high-efficient intracellular ROS scavenger for alleviating the lipopolysaccharide induced inflammation in macrophage

Reactive oxygen species (ROS), acting as functionalized molecules in intracellular enzyme reactions and intercellular communication of immune response, play vital roles in biological metabolism. However, the inevitably excessive ROS caused oxidative stress is harmful for organ tissue causing the unexpected local anaphylaxis or inflammation. Here, we demonstrate the carbon dots (CDs), made of citric acid and glutathione via one-step hydrothermal method, as a high-efficient intracellular ROS scavenger for alleviating the lipopolysaccharide induced inflammation in macrophage. These CDs have broad-spectrum antioxidant properties and the total antioxidant activity exceeds 51.6 % higher than that of the precursor, namely glutathione in the same mass concentration. Moreover, their anti-oxidative performance in macrophage inflammation induced by lipopolysaccharide (LPS) was investigated and found that CDs can efficiently remove up to 98 % of intracellular ROS, notably inhibiting nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway as well as decrease the expression level of inflammatory factor IL-12. Our results suggest that CDs can serve as a high-efficient intracellular ROS scavenger and could be employed to cope with oxidative stress-induced diseases.