To assess the mechanism by which mPEG-SPA-MDSPI16 can treat ALI, we established an LPS-induced neutrophil inflammation model and found that mPEG-SPA-MDSPI16 can significantly reduce the production of neutrophil ROS in mice and significantly reduce the expression of IL-6, TNF-α, IL-1β, and other proinflammatory factors. This evidence concerns the gene TNF and acute respiratory distress syndrome.