多嵌段聚氨酯材料的表面结构与生物相容性

Surface Structure and Antithrombogenicity of Segmented Polyether Polyurethane

人工心脏隔膜用的聚氨酯材料至少应具有抗凝和耐挠曲的性能。通常提高聚氨酯的耐挠曲性多从调整其本体结构来考虑。由于聚氨酯的本体结构与表面结构不同,在挠曲过程中本体的相分离变化会影响表面软段的取向行为。因此为了知道挠曲对聚氨酯抗血凝性能的影响,作者从1983年起通过自制的耐疲劳试验代,利用XPS,FT-ATR-IR,WAXD,SAXS,SALS和血小板粘附试验等方法,测得在疲劳过程中聚氨酯表面的微相分离程度下降,聚醚软段含量减少,并导致其抗凝血性能下降。这样作者便把聚氨酯在反复变形过程中的本体形态,表面结构和生物相容性间的关系联系起来了。

Segmented polyetherpolyurethane for artificial heart diaphram should have antithrombogenic and flexible properties in long term. In the last two decades, attention hasbeen paid to the regulation of the bulk structure of polyurethane for the improvement of its flex life. Since 80's, it has been known that structure of the surface and the bulk or polyurethane are different. In the fatigue procese, changes of phase separation in the bulk may cause the orientation behaviour of the polyether soft segment in the surface layer. By using the fatigue testing machine designed by the authors and XPS, FT-ATR-IR, WAXD, SALS and platelet count methods in the investigation of the effct of the fatigue process on the antithrombogenicity of polyurethane, we found that during the fatigue process, the degree of phase separation decreased in the surface layer of polyurethane leading to the content of soft segment decreased and the antithrombogenic properties unsatisfactory. Thus, the relationship between the morphology or the bulk, the surface structure and the biocompatibility of polyurethane under the fatigue process has been established.