Preparation of Novel Biocompatible polymeric Additives and Modification of Biomedical Materials Using the Additives

为了改善嵌段聚氨酯(SPU)的血液相容性，将2-甲基丙烯酰氧乙基磷酰胆碱(MPC)聚合物共混入SPU中，采用溶剂挥发法制备了SPU与MPC聚合物共混膜。对与MPC聚合物(SPU/MPC聚合物)共混的SPU膜的表面分析表明，与成膜过程中与空气接触的SPU膜相比，MPC聚合物主要集中在与基材接触的SPU膜表面。MPC聚合物的微区尺寸变小，但微区数目增加。MPC聚合物MexED与SPU的用量影响分散状态。由拉伸应力-应变测量确定的SPU膜的机械性能，即使在添加MPC聚合物后也变化很小。用胶体金标记法检测SPU/MPC聚合物膜与人血浆接触后吸附在膜表面的血浆蛋白。白蛋白和纤维蛋白原在SPU膜上均可观察到，但在SPU/MPC聚合物膜上这些蛋白的含量减少。结果表明，MPC聚合物的共混有效地改善了SPU的血液相容性。在SPU膜中加入MPC聚合物可显著降低细胞粘附性。因此，将MPC聚合物共混在SPU膜中是一种有效的非血栓形成方法。利用这种SPU/MPC聚合物共混物制备了小直径血管假体。与普通或原始假体相比，SPU/MPC聚合物共混体假体在8个月以上的时间内，即使将假体植入兔的血管内，也不会发生缝合。

To improve the blood compatibility of a segmented polyurethane (SPU), 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer was blended in the SPU.The blended membranes composed of SPU and MPC polymers were prepared by a solvent evaporation method. Surface analysis of the SPU membrane blended with the MPC polymer (SPU/MPC polymer) revealed that the MPC polymer was concentrated at the surface of the SPU membrane which contacted the substrate compared with that which contacted air during the membrane formation period. The size of the domains of the MPC polymer became smaller but the number of the domains increased. The amount of the MPC polymer mexed with SPU affected the dispersion state. The mechanical properties of the SPU membrane, as determined by tensile stress-strain measurements, changed very little even after addition of the MPC polymers. Plasma proteins adsorbed on the SPU/MPC polymer membrane surface after contact with human plasma were detected by gold-colloid labeled immunoassay. Both albumin and fibrinogen were observed on the SPU membrane ; however, the amount of these proteins was reduced on the SPU/MPC polymer membrane. It was concluded that the blood compatibility of the SPU was effectively improved by the blending of the MPC polymer. The addition of MPC polymer in the SPU membrane dramatically reduced cell adhesion. It is concluded that the blending of the MPC polymer in the SPU membrane is an effective method to impart nonthrombogenicity. By using of this SPU/MPC polymer blend, small-diameter vascular prosthesis was prepared. The prosthesis indicated excellent performance compared with normal or original prosthesis, that is, during more than 8 months the SPU/MPC polymer blend prosthesis did not osculate even when the prosthesis was implanted into rabbit vain.