Preparation Of SE-LNPs And Its Anti-atherosclerosis Effect

Background:Atherosclerosis leads to ischemic heart disease,stroke and peripheral artery disease.Over the past 20 years,the incidence and fatality rates of atherosclerotic diseases have increased significantly in China.At present,the pathogenesis of AS is still not very clear,involving dyslipidemia,inflammation,oxidative stress,immune disorders,etc.Simvastatin is a commonly used drug to regulate blood lipid in the prevention and treatment of AS,but it has short half-life,low bioavailability,and adverse reactions,including muscle symptoms and liver toxicity.Oxidative stress is one of the main pathogenic factors of AS.However,small molecules of antioxidants have not shown positive effects on preventing and treating AS in vivo.Epigallocatechin gallate(EGCG)is a natural polyphenol compound in green tea,which has a variety of cardiovascular protective effects,including anti-oxidation,anti-inflammation,anti-thrombosis,anti-angiogenesis and antiarteriosclerosis.However,its low bioavailability and poor stability limit its application.In order to solve the disadvantages of low bioavailability and poor stability of simvastatin and EGCG,we tried to construct a kind of liposome nanoparticles(SE-LNPs)that can deliver simvastatin and EGCG and target macrophages,so as to improve the bioavailability and stability of these two drugs.The purpose of this study was to explore the therapeutic effect and mechanism of the liposome nanoparticles on AS,providing laboratory basis for the clinical transformation of AS treatment from the perspective of targeting macrophages.Objective:To develop a stable,intravenous multifunctional nano-liposomes(SE-LNPs)carrying simvastatin and EGCG,which can regulate blood lipids,antioxidation,anti-apoptosis,anti-inflammation and M2 polarization,and achieve the purpose of targeting macrophages to treat atherosclerosis.Methods:In this study,liposomal nanoparticles(SE-LNPs)were prepared using simvastatin(SIM)as a model drug,EGCG as an antioxidant and distearyl phosphatidylcholine(DSPC)as the main carrier.The cytotoxicity,phagocytosis,antioxidant and anti-apoptotic properties of the nanoparticles were tested in vitro.ApoE-/-atherosclerotic mice were treated with nanoparticles,and changes in oil red staining,lipid profiles,and HE and Masson sections of aortic roots were observed.Results:1.Liposome nanoparticles had been successfully prepared.SE-LNPs were spherical.The size of LNPs and SE-LNPs were(185.47±0.61)nm and(208.90±3.99)nm,respectively.The Zeta potential was almost-20 mV.The polydispersity index of all nanoparticles was less than 0.2.The loading capacity(LC)of SIM in SELNPs and encapsulation efficiency(EE)were(43.39±7.6)%and(93.57±1.28)%,respectively.SE-LNPs had slow-release behavior.2.No cytotoxicity was observed in the SE-LNPs group in vitro.Compared with endothelial cells,macrophages phagocytized more Rho-LNPs.SE-LNPs effectively cleared ROS in macrophages under stress,but did not reduce the level of ROS to physiological concentration.SE-LNPs effectively inhibited macrophage apoptosis caused by oxidative stress.SE-LNPs promoted the polarization of macrophages towards M2,and decreased the levels of IL-1β,TNFα and IL-6.3.SE-LNPs decreased the levels of TG,TC and LDL-C in the blood of high-fat induced ApoE-/-mice,but had no significant effect on HDL-C.SE-LNPs decreased the necrotic core area of AS plaques and aortic root in ApoE-/-mice,and increased the collagen content in the aortic root plaques,thus increasing the stability of the plaques。Conclusion:SE-LNPs could attenuate oxidation,inflammation and apoptosis,promote M2 polarization,and reduce blood lipids and lesions,which is a reliable and selective treatment for atherosclerosis.