Study On Blood Compatibility Of Anticoagulation Biomaterials

Biomaterial's blood compatibility is that its surface has ability to anticoagulate and it affects on hemolysis, platlete function, leucocyte decreasing, alexin activation and blood physiological function. It also includes that plasma proteins don't denature, all kinds of enzymes in blood don't inactivate, electrolyte osmotic pressure is not changed in blood and immunoreaction isn't happed. All these refer to cellular level reaction, which includes platlete adhesion, hemolysis and leucocyte decreasing, plasma proteins level reaction, which involves coagulation system activation and fibrinolytic system activation, molecular level reaction, which includes immunore component transformation, thrombocyte receptor deliverance and ADP deliverance. In this way, blood comaptibility refers to many factors and its mechanism is complex. So single and isolate parameter can't describe biomaterial's blood compatibility. In this paper, we analyze the characters of blood and material interaction systematically. According current specification, a blood compatibility evaluation method was set out. On this base, anitcoagulation biomaterials' surface characters was studyed. We also made use of the fuzzy mathematics and the analytic hierarchy process to evaluate the blood compatibility.The results of blood compatibility show that: (1) heparin can maintain the structures of hemocyte and plasma proteins. At the same time, anticoagulation ability of PEU/LCP comes from synergy of heparin, LCP and microfacies separating structure. (2) in SEM study and plasma proteins analyses, increasing hydrophilicity can reduce plasma proteins adsorption and increase ratio of albumin in plasma proteins. Heparinazation does that much and eliminate proteins denature. PEU/LCP does work the best because of its microfacies separating structure. (3) by study on platlete adhesion, increasing hydrophilicity and heparinazation reduced the platlete adhesion. PEU/LCP decreased that the best. (4) observating hemocyte variation, all materials' hemolysis rate was blow 5%. Increasing hydrophilicity and heparinazation reduced hemolysis rate. When PEU/LCP contacted with blood, swelling phenomena will be happend. That had bad influence with erythrocyte. In leucocyte adsorption study, it showed that leucocyte adsorption quantity of all materials is in the same level.surface characters study shows that: (1) grafting on the polymer can improve hydrophilicity and increase surface free energy. Blending of polymer and LCP can increase surface free energy greatly. (2) By calculation, we got the interfacial tension of materials and blood. According blood compatibility study before, material, which has low interfacial tension, has good compatibility. (3) we find out why PEU/LCP has the lowest interfacial tension. It's because LCP moved from interior material to exterior material. Then a LCP layer was formed. Because the single factor blood compatibility experiments had different results, we used fuzzy mathematics mode to evaluate 5 materials. In fuzzy mathematics mode, factor of evaluation must distribute weight. So the analytic hierarchy process was be introduced. In our evaluation, recalcification time, changed quantity of platlete, changed quantity of coagulation-factor and globularprotein influented results the best. PEU/LCP had the best blood compatibility and whole heparinazed PES was following. The results also show that hemolysis rate of PEU/LCP must be improved. Whole heparinazed PES will do some work to reduce leucocyte adsorption and increase hydrophilicity.