采用层层自组装与光化学修饰法在聚氨酯表面固定生物多糖衍生物

采用层层自组装技术与光化学修饰方法相结合在聚氨酯材料表面固定生物多糖衍生物,首先合成具有光反应活性的叠氮壳聚糖,再在聚氨酯基材表面进行叠氮壳聚糖与香菇多糖硫酸酯的层层自组装,然后通过光化学反应对自组装多层膜修饰层进行交联,制备得到生物多糖衍生物层层自组装与光化学表面修饰的聚氨酯材料.通过红外光谱、X射线光电子能谱、水接触角测量仪、抗菌活性测试、溶血试验和血小板黏附测试等方法对被修饰聚氨酯材料的表面性能和生物性能进行了分析,测试结果表明修饰后的聚氨酯材料表面的亲水性和血液相容性得到改善,并且被修饰材料对大肠杆菌具有良好的抑制效果.

IMMOBILIZATION OF POLYSACCHARIDE DERIVATIVES ON POLYURETHANE SURFACE THROUGH LAYER-BY-LAYER SELF-ASSEMBLY AND PHOTOCHEMICAL MODIFICATION

Polysaccharide derivatives were immobilized on the surface of polyurethane(PU) through layer-by-layer self-assembly technique and photochemical modification method.At first,azido-chitosan(AzCS) was synthesized and immobilized on the polyurethane substrates by UV irradiation.Then,lentinan sulfate(LS) and azido-chitosan were alternatively deposited on the polyurethane substrates through layer-by-layer self-assembly technique.Finally,the self-assembled multilayers were cross-linked by UV irradiation.From above steps,the polysaccharide derivatives modified polyurethanes were prepared.The surface properties of the modified polyurethanes were evaluated by infrared spectroscopy,UV-Vis spectroscopy,X-ray photoelectron spectroscopy and water contact angle measurement.The antibacterial activity against Escherichia coli and blood compatibility of unmodified and modified PU were tested in vitro,respectively.The results showed that the water contact angle of the modified surfaces decreased gradually during the successive buildup of the multilayers.The hemolysis test and platelet adhesion test both indicated that the blood compatibility of PU surfaces was improved after surface modification.Moreover,the modified surfaces showed antibacterial activity against Escherichia coli.The number of viable Escherichia coli on the modified surface decreased by 49%.Thus,the surface modification of polysaccharide derivatives through layer-by-layer self-assembly and photochemical modification not only improves the hydrophilicity and hemocompatibility of the modified PU,but also introduces special antibacterial bioactivity onto the modified surfaces.