Study On Serum Lipoprotein In Patients With Coronary Artery Disease Based On Asymmetrical Field Flow-field Fractionation

ObjectiveThe report on cardiovascular diseases in China(2017)pointed out that cardiovascular disease accounts for more than 40%of the disease deaths of residents,and it is the first cause of death for Chinese residents.Cardiovascular disease has become a major public health problem,it is imperative to prevent cardiovascular disease.Coronary artery disease(CAD)is a very common cardiovascular disease.Clinically,lipoprotein-cholesterol contents are often used as a predictor of CAD at present.However,other studies have found that there is still a risk of CAD when lipoprotein-cholesterol contents at a normal level,and assessing the probability of CAD from the perspective of serum lipoprotein-cholesterol levels has certain limitation.With in-depth research,apolipoproteins are closely related to the development of CAD,especially apolipoproteins A1 carried by high density lipoprotein(HDL)and apolipoproteins B carried by low density lipoprotein(LDL).In this experiment,separation and characterization of the lipoproteins in serum of CAD patients was performed.The ratio of LDL to HDL was investigated to find new CAD predictors.Method1.In this thesis,asymmetrical field flow-field fractionation(AF4)coupled with UV/Vis detector(AF4-UV/Vis)was used to separate and characterize lipoproteins in serum of CAD patients.Since the analysis results of the sample are greatly affected by the separation conditions of the system,the influence of the AF4 separation conditions(i.e.injection volumes,cross-flow rates,carrier ionic strengths,membrane types,and channel thickness)on analysis results was investigated.In addition,the repeatability of AF4-UV/Vis was verified to ensure the applicability of the AF4 system.In order to eliminate the interference of free proteins in serum samples on the results of lipoproteins analysis during the separation,Sudan Black B(SBB)was selected to stain the lipoproteins specifically in the serum,and the effect of SBB on the analytical results was studied.Meanwhile,the cross-flow rates and carrier ionic strengths were optimized,in order to reduce the adsorption of the sample on the surface of the membrane,improve the recovery and resolution.AF4-UV/Vis analysis of serum samples from healthy people and CAD patients was performed under the optimal conditions of the separation.ResultThe optimal conditions were V_c=2 mL/min and I=100 mM.The repeatability of the AF4-UV/Vis(n=5)was carried out under the optimal conditions of the separation,and the experimental results demonstrated that AF4 analysis of serum lipoproteins has a good reproducibility.Separation and characterization of serum lipoproteins stained with SBB by AF4-UV/Vis showed that the content of LDL and HDL in healthy human have some differences with that in CAD patients.ConclusionThis study demonstrated that AF4 can achieve baseline separation of HDL and LDL in serum.In addition,the experimental results showed that the change in content of HDL is more susceptible to CAD than LDL.