Preparation And Properties Of Tri-phosphoric Acid-polyurethane Nanoparticles Surface-modified Polyurethane Blood Compatibility Materials

In recent years,the demand of biomedical macromolecule material around the world is growing,especially cardiovascular materials.At the same time,it's a difficulty to conquer the difficulties.Because it happens that thrombus caused by adhesion of plasma and protein when the blood flows through the surface of the material.Polyurethane(PU)is a kind of polymer consisting of carbamate group,owing a relatively good biocompatibility,hemocompatibility and mechanical properties.So it is being used as important material contacting blood with a wide of range of uses in interventional catheter,the artificial heart and so on.Although of PU's biocompatibility and hemocompatibility,it cannot satisfy the needs of actual operation.It inevitably brings out some problems such as coagulation,bacterial infections and damage to bodies due to inserting or being implanted devices about whether be treated successfully when materials contact blood.People have done various medical modification to the polyurethane in recent decades against coagulation and infection aroused of inserting and implanting.PUI-STTP was synthesized in this article.It's structure,blood compatibility,tissue compatibility were characterized and the result shows their excellent.PU membrane was modified in surface by PUI-STTP adopting settlement method,preparing PU/PUI-STTP membrane and studying the structure and nature of PU/PUI-STTP through SEM,FTIR and TGA.The blood compatibility of PU/PUI-STTP membrane was characterized through red blood cell experiment,the complex calcium experiment and hemolysis.The result suggests that the method can form a concave-convex nanoscale structure that is similar with the lining of blood vessels on the surface of PU.Scanning electron microscopy(SEM)images shows that the method can form a nanoscale concave-convex structure on the surface of PU,more similar to the actual blood structure.The static contact angle test results that he hydrophilic of PU are increased obviously owing to PUI-STTP.Thermogravimetric(TG)and tensile test results show that the introduction of PUI-STTP will not damage the thermal stability and mechanical properties of PU membrane.Platelet adhesion experiments show that the amount of platelet adhesion on the surface of PU film modified by PUI-STTP reduced significantly compared to blank PU.It suggests that the ability of anti-platelet adhesion of PU/PUI-STTP film improved significantly.Hemolysis experiments show that hemolysis of PU film modified by PUI-STTP nanoparticles was less than 5%,fitting with international standards.The experiment of clotting time of recalcification shows that the time of modified PU film was longer than blank PU film,suggesting that hemocompatibility of PU modified by PUI-STTP improved.And dynamic coagulation tests suggest that anti-clotting properties of modified material had some progress.Cytotoxicity test shows that the toxicity of modified is less than that of blank PU after 24h and 72h.It can been studied that EPCs cells was easier to grow on the modified PU while that on blank PU shedding gradually through the growth of EPCs cells on modified PU and blank PU.