Targeted counteracting of overactive macrophages by melittin stable-loaded solid lipid nanoparticles alleviates cytokine storm and acute inflammatory injury
Yuan Zheng, Ningshuang Ye, Yang Yang, Miao He, Sanyuan Shi, Yunxuan Zhang, Samuel Kesse, Xiaohui Wei, Yuhong Xu, Ping Nie, Jinliang Peng
Abstract
The continuous activation of macrophages play a critical role in the pathogenesis of cytokine storm (CS). Considering that CS results from the participation of multiple cytokines, the therapeutic effect of a single cytokine or its receptor-targeted blockade therapy remains uncertain. Melittin, which can systematically suppress the overexpression of proinflammatory mediators via inhibiting the mitogen-activated protein kinase and nuclear factor kappa-B pathways in activated macrophages, shows great potential in alleviating CS and acute inflammatory injury (AII). However, its clinical application is limited by its hemolytic activity, non-specific cytotoxicity and lack of targeting. In this study, a folic acid-modified and melittin stable-loaded solid lipid nanoparticle (Fa-MpG@LNP) with a core–shell structure was developed for CS control via targeted inhibition of the overproduction of proinflammatory mediators in activated macrophages with specific expression of folate receptor-β. The resultant Fa-MpG@LNP showed ideal physicochemical properties and stability, low hemolytic activity and non-specific cytotoxicity, and it can specifically bind to lipopolysaccharide (LPS)-stimulated macrophages and effectively reduce the elevated levels of proinflammatory mediators. After intravenous administration, the Fa-MpG@LNP accumulated at inflamed tissue and significantly downregulate the overproduction of proinflammatory cytokines in tissue-infiltrated macrophages, resulting in a significant decrease of cytokine concentration in inflamed tissue and serum in LPS-induced acute pneumonia mice, and finally alleviate AII with undetectable toxic side effects. These results indicate the clinical application potential of Fa-MpG@LNP in alleviating CS and its related symptoms. • The folate-modified and melittin stable-loaded solid lipid nanoparticles Fa-MpG@LNP was successfully developed. • The Fa-MpG@LNP exhibits almost no hemolytic activity and non-specific cytotoxicity. • The Fa-MpG@LNP can significantly downregulate the overexpression of proinflammatory cytokines in activated macrophages. • The MpG@LNP can remarkably alleviate cytokine storm and acute inflammatory injury with negligible toxicities.