The Screening Of The Preparative Method And The Optimum Condition For Heparin-dexamethasone-coating Pipes Of The Cardiopulmonary Bypass Circuits

In recent years, heparin coating was used more and more in cardiopulmonary bypass pipe line and artificial cardiopulmonary support devices. Heparin coating technology is using of chemical or physical reactions, etc., combinating of heparin in the inner surface of the pipeline solidly. Application of heparin-coated pipeline pipeline system can greatly improve the biological, blood compatibility, reduce inflammation, reduce blood damage and reduce postoperative complications, reduce the rate of hospitalization and mortality after cardiac surgery, provide a basis and conditions for the generalization of the artificial heart and lung support devices, improve the cure rate of severe heart and lung diseases.Currently no own production of heparin-coated pipe in our country, most need to import, but very expensive, limit the application of the heparin-coated pipe in the cardiopulmonary bypass.also limit the generalization of the ECMO. The study is to approach from the three new heparin-coated, select one of the best ways, and filter its optimum conditions.OBJECTIVE:Screen the best method to the independently developed heparin-dexamethasone coated pipe, and screen the best conditions of the method. Preliminary test the effect of heparin coated pipe and heparin-dexamethasone coated pipe.METHODS:According to sodium alginate, polyvinyl alcohol, chitosan has good biocompatibility, bio-adhesion, security, water-soluble, package small molecules matter, slow-release properties and polyelectrolyte, modify the inner surface of the PVC pipe with the Ca2+.make use of that the sodium alginate can easily cross link with divalent cations to form network polymer, prepare three sustained-release heparin-dexamethasone coating material which are the Alginate heparin-dexamethasone, alginate-polyvinyl alcohol-heparin-dexamethasone and sodium alginate-chitosan-heparin-dexamethasone coating material. Compare the amount of heparin-coated, amount of dexamethasone-coated, stability, IR spectroscopy. transparency of the three coating material, choose the best coating method;and then screen the best conditions of the method. At the last, test the effect of coated pipe by anticoagulant experiment, protein adsorption experiment and the show in the electron microscope.RESULTS:Detecte and determinate the amount of heparin-coated, amount of dexamethasone-coated, stability, IR spectroscopy, transparency of the three coating material respectively, compare of the indicators. Among them, the amount of heparin-coated, amount of dexamethasone-coated and the IR have no significant difference; sodium alginate—heparin-dexamethasone release coating composite pipe and alginate-chitosan-heparin-dexamethasone release coating composite pipe have the better transparency, alginate-polyvinyl alcohol-heparin-dexamethasone pipe have the poor transparency; sodium alginate-heparin-dexamethasone coating pipe have the best stability, alginate-polyvinyl alcohol-heparin-dexamethasone coating pipe followed, alginate-chitosan-heparin-dexamethasone coating pipe the worst. Therefore, comprehensive comparison of the indicators, can filter out the sodium alginate-heparin-dexamethasone complex release coating pipe as the best coating pipe.Prepare alginate cross-linked heparin coating pipes under different conditions, determinate the amount of heparin-coated and dexamethasone. stability, transparency of the coating material, falling of dexamethasone from the coating pipe respectively, the best condition of the method is45℃for6h heparin and dexamethasone with sodium alginate mixed reaction.CONCLUSION:Among the three new heparin-dexamethasone-coated methods we research independently, the best method is alginate cross-linked heparin and dexamethasone coating.and the the best condition of the method is45℃for6h heparin-dexamethasone with sodium alginate mixed reaction. The results of anticoagulant experiment, protein adsorption experiment of the coating pipe are well: and there is no significant difference between heparin-coated pipe and heparin-dexamethasone-coated pipe.