Study On The Surface Modification Of Expanded Polytetrafluoroethylene Artificial Small Blood Vessel With Dopamine Blend Polyethylene Imine And Graft Heparin

1 The background and significance of the researchThere are many risks for cardiovascular disease in China,and there is an obvious trend of prevalence,which leads to a increased growth in the number of cardiovascular diseases in China.Generally speaking,the prevalence and mortality of cardiovascular diseases in China is still on the rise.According to China's latest cardiovascular disease report,China ranked in the first place in the cardiovascular disease mortality,accounting for more than 40%of the residents disease mortality.Coronary artery bypass grafting in cardiac surgery(CABG)is an important method to solve coronary atherosclerosis disease.The amount of CABG surgery in China is increasing year by year.In coronary artery bypass grafting(CABG)surgery,the selection of graft vessels has been a hotspot issue.Although autologous blood vessel is an ideal vascular material,but the material is limited,and it is harmful to the rehabilitation of patients.Now small caliber artificial blood vessels(Diameter<6mm)is poor in anticoagulant performance,and it's easy to form thrombus in vivo,therefore it still can't be used in clinical practice.Heparin is a widely used anticoagulant in clinic practices' fixing it on the surface of artificial blood vessel to play an anticoagulant has always been a hot spot for the surface modification of artificial small blood vessel.2 Purpose2.1 Preparation of expanded polytetrafluoroethylene graft heparin with dopamine blend polyethylene imine2.2 Study on anticoagulant effect and stability of expanded polytetrafluo roethylene graft heparin grafted with dopamine blend polyethylene imine in vitro3 Research methods3.1 Oxygen plasma pretreatment of expanded polytetrafluoroethylene artificial small vessels;3.2 Dopamine blend polyimide was used to treat expanded polytetrafluoroethylene(PTFE)artificial small blood vessels.3.3 Heparin grafted with dopamine/polyimide was grafted onto small blood vessels and characterized.3.4 In vitro experiments:To evaluate the anticoagulant performance and stability of the composite and unmodified blood vessels,platelet adhesion test,calcium recovery test and scour test were carried out respectively.4 Results and discussions4.1 After the processing of dopamine/polyimide,the results of the X-ray photoelectron spectroscopy(XPS)showed that there is a N peak,which is only belonged to dopamine and ployimide,meanwhile,the change of C peak also supported the successful modification of dopamine and polyimide.In the XPS results of secondary grafted heparin,there was a unique peak of heparin,which confirmed the successful grafting of heparin on the surface of artificial small blood vessels.4.2 In the in vitro study,the platelet adhesion on the surface of the composite vessels in the renaming group was less than that in the unmodified group,which indicated that the composite vessel had good antiplatelet properties.In the recalcification experiment,the time of recalcification in the unmodified group was maintained at 8 minutes to 10 minutes,while in the vascular composite group,the recalcification time was about 42 minutes and 36 seconds,and there was no white flocculent precipitate in the other five groups during the first hour of the experiment.These results are in accordance with the results of platelet adhesion,indicating that the composite vessels have good anticoagulability.In the scoring experiment,the composite vessel was flushed by PBS solution on January.The results showed that the modified substance was well-fixed,and the grafted heparin grafted by this method had good stability.