Study On SIS Film Surface Modification By Plasma And The Blood Compatibility

When the blood-contacting polymers contact with blood, complicated interaction will happen on the interface so as to form coagulating reaction and thrombus. Therefore, blood-contacting polymers need to be modified to improve their antithrombogenic properties, which have been focused in research. This article has used plasma surface modification methods to introduce some active groups on SIS film surface to improve its blood compatibility. It includes the following contents mainly:1,Ar, O₂ plasma have been used separately to modify SIS film surface, The modified films surface chemical constitution and the elemental composition were analyzed by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photon spectroscopy (XPS); The surface free energy, surface hydrophilicity and blood compatibility of these modified SIS films were studied and the influence of gas flow, treating power, treating time and gas sorts on these properties were studied as well. The best reaction conditions were determined. In O₂ plasma processing, when power was 50W and reaction time was 2min, the blood compatibility of the modified SIS film was best, APTT was prolonged 18.6s; In Ar plasma processing, when power was 60W and reaction time was 2 min, the blood compatibility of the modified SIS film was best, APTT was prolonged 15.4 s. The blood compatibility of the SIS film treated with O₂ plasma was better than that treated with Ar plasma.2,Polyethylene glycol (PEG) of different molecular weights has been grafted on SIS film to improve blood compatibility through Ar plasma initiation. The modified films surface chemical constitution and the elemental composition are analyzed by ATR-FTIR and XPS; The surface free energy, surface hydrophilicity and blood compatibility of these modified SIS films were studied and the influence of PEG graft concentration and molecular weight on these proprieties were studied as well. The best reaction conditions was determined. When PEG graft concentration was 3% and molecular weight was 2000, SIS graft exhibited the best blood compatibility. Water contact angle decreased from 86.3°to 42.6°, APTT was prolonged 52.6s.3,SIS/PEG blend films with a different blend ratio has been prepared by mixing aqueous solution of SIS and PEG, Ar plasma was used to modify SIS/PEG blend film surface as well. The modified films surface chemical constitution was analyzed by ATR-FTIR and blood compatibility in different treating methods was also study. When PEG blend ratio was 20% and Ar plasma treating time was 1.5min, blend film had the best anticoagulation.Research of vitro blood compatibility indicated that APTT of the modified SIS film were all prolonged, changes of PT was not obvious. This indicated that the modified surface of SIS films can not influence markedly on extrinsic coagulant system.