Effects of composite Chitosan/Heparin coated membrane through a layer by layer self-assemble technique on stent thrombosis

Objective:To investigate the influence of the composite chitosan/heparin coated membrane through a layer-by-layer self-assemble technique on stent thrombosis.Methods:The composite chitosan/heparin coated membrane,which was assembled through a layer-by-layer technique,was attached to the inside surface of cylinder made from 316L stainless steel flake to form membranes of different layers of chitosan/heparin.The activated partial thromboplastin time(APTT),prothrombin time(PT)and thrombin time(TT)of the whole blood samples of healthy controls were examined by clotting method;and the stability of its anticoagulation effect was also examined.The influence of the prepared composite chitosan/heparin coated membrane on coronary stent thrombosis was investigated using swine model of arteriovenous shunt thrombus.Results:The APTT and TT were significantly longer in the composite coated membrane group compared with those of 316L stainless steel group(P0.01).Moreover,the prolongation of APTT and TT was correlated with the increase of coated layers.The anticoagulant function of chitosan/heparin coated membrane was stable for two weeks(P0.05).The weight of thrombus was significantly lower in the coated stent group than that in 316L stainless steel group(P0.001).Conclusion:The composite chitosan /heparin coated membrane made by layer-by-layer self-assemble has effective and stable anti-thrombotic function.