Research On The Anti-restenosis Mechanism Of Elemene And Detection Of Its Sustained-Release Coating

Nowadays percutaneous coronary intervention is one of the main methods for treating coronary atherosclerosis cardiovascular disease,but the in-stent restenosis rate of 3-6 months after the incidence reaches 30%-50%. Therefore, the mechanism of restenosis is a focus in the field of cardiovascular disease research. In recent years, rapamycin and taxol drug-coating stents for in-stent restenosis have been widely used. But there are still endothelial delay, the later thrombosis, and other side effects. Consequently, developing a new, less side effects, more safe and effective coating drug is of great significance.In-stent restenosis is the comprehensive result of many factors, including vascular endothelial injury and thrombosis, vascular smooth muscle cells proliferation, migration and vascular remodeling and a series of pathological process. Especially, the excessive proliferation of smooth muscle cells, migration to intima, secreting extracellular matrix are the main causes of the in-stent restenosis. Elemene is an antitumor drug, developed by China and extracted from Chinese herbal medicine curcuma wenyujin. The efficacy of elemene on inhibiting tumor cells growth is efficient and broad-spectrum. Previous research shows that elemene can be used in the prevention and treatment of in-stent restenosis, endowing elemene with great potential in treating cardiovascular system diseases. The concentration of an ideal stent coating drug in the blood vessels should keep within the effective drug concentration for a long time. Coincidentally, liposome has the advantages of long-term slow-release and actively targeting to and gathering at target with high efficient continuous treatment. It is generally accepted that the proliferative activity of smooth muscle cells led to the pathogenesis of neointimal hyperplasia after vascular injury. This study aim at investigating whether elemene could inhibit the growth of smooth muscle cells, promote apoptosis of smooth muscle cells, and influence the gene expression after mechanical stretch. Elemene liposome was prepared by ethanol injection method. Elemene sustained-release membranes were characterized by electrostatic spray and cultured with smooth muscle cells to test the effect of released elemene on smooth muscle cells proliferation. The main research contents and results of this study are listed as follows:①Vascular smooth muscle cells derived from rat aortic were cultured with elemene to evaluate their proliferation and migration. It was found that when the concentration of elemene is above 12.5μg/ml, in a dose-dependent manner, elemene inhibited proliferation and migration of smooth muscle cells in cultured smooth muscle cells, and blocked the connections between cells(P<0.05).② Smooth muscle cells derived from rat aortic were cultured with elemene to evaluate cycle, apoptosis, cytoskeletal protein F-action, intracellular Ca2+, Inc RNA chip and expression levels of PCNA, P53, Cx43. Experimental results showed that elemene can arrest the cell in S/G2 phase, and promote apoptosis, in a dose-time dependent manner. The results showed elemene could cause intracellular free Ca2+ concentration increased about 1 times and then return to normal. In the selection of 4×44k gene expression profiles of Inc RNA chip, 1417 gene expressions showed differences, including 34 signaling pathways such as PPAR, MAPK, Akt and Erk1/2.③ Elemene liposomes were prepared by ethanol injection method. Electrostatic spray nanoparticles contained elemene liposomes were got by the method of uniaxial electrostatic spray. Elemene membrane could control smooth muscle cells proliferation after 24 h. Coating particles size was relatively uniform. Elemene liposome coating had obvious slow-release effect(P<0.05), and could inhibit cells growth, proliferation, and block cell cycle. Meanwhile, the inhibitory effect of elemene liposome coating was dose-dependent.In conclusion, the cell culture results demonstrated that elemene is effective in inhibiting VSMC proliferation by arresting cell cycle, inducing apoptosis and blocking the connections between cells. Multiple genes involved in the regulation of a series signal pathway. Elemene liposome had slow-release effect and could inhibit the proliferation of smooth muscle cells. Therefore, the study of using elemene as a stent coating drug provided experimental basis for its application in the field of cardiovascular intervention.