聚氨酯硬段改性材料心室辅助装置血液相容性及毒理学研究

通过溶血试验、动态凝血时间试验、血小板黏附试验及全身急毒试验,评价聚氨酯硬段改性材料作为人工心室辅助装置材料的血液相容性和全身毒性,结果显示硬段改性聚氨酯材料血液相容性优于未改性聚氨酯材料,无明显全身毒性反应.     

介入用聚氨酯材料的血液相容性研究

介入导管优良的血液相容性是确保血管内介入技术安全可靠进行的重要因素，我们对自己合成的四种介入导管用聚氨酯材料的血液相容性进行了评价，包括溶血试验、血小板黏试验、动态凝血时间试验和动态血栓形成实验。结果表明，其中的H50-100和H60-100具有优良的血液相容性，完全可以用作介入导管材料。此外，还讨论了聚氨酯结构与血液相容性的关系。     

五种国产医用嵌段聚醚聚氨酯的细胞毒性评价

国内最近研制成功的医用嵌段聚醚聚氨酯(SPEU)是一类用于人工心脏,血管及其辅助装置的抗凝血材料,经两种细胞培养细胞毒性试验方法评价证明具有优良的生物相容性。实验结果报告如下。     

新型MAO钛基生物材料的血液相容性研究

目的初步评价新型钛基材料的血液相容性。方法采用新西兰大白兔新鲜全血,抗凝后分别与实验组和阳性对照、阴性对照组接触,用紫外-可见光分光光度计比色,评价各组的溶血率。实验符合国际化标准组织规定要求。结果新型微弧氧化钛基材料直接接触溶血率为0.79％,符合医用材料的溶血率不大于5％的要求。结论新型钛基材料具有良好的血液相容性。     

改进医用聚氨酯血液相容性的研究进展

医用聚氨酯材料具有良好的生物相容性及机械性能,因而已被用于制作人工器官。本文综述了近年来在改进医用聚氨酯血液相容性方面的研究进展,包括新型聚氨酯材料的合成、聚氨酯材料的化学改性、在聚氨酯材料上固定具有抗凝血活性的物质。作者认为,目前医用聚氨酯材料还存在一定缺陷,今后应在阐明材料结构与血液相容性的关系的基础上,进一步开发力学性能和长期抗凝血性好的聚氨酯材料。     

生物医用脂肪族聚氨酯的合成、表征及血液相容性研究

采用一步法合成以4，4’—甲烷二环巳基二异氰酸酯(HMDI)、扩链剂1，4—丁二醇(BDO)为硬段，聚四氢呋喃醚(PTMG)为软段的脂肪族聚氨酯。并对所合成材料进行了傅立叶变换红外光谱分析、力学性能测试、水接触角测试、溶血实验及体外静态血小板粘附实验。结果表明，本论文合成的聚氨酯断裂强度可达30MPa以上，可与芳香族聚氨酯材料相比拟，而其断裂伸长率、断裂永久形变、亲水性能较之更好，具有理想的机械力学性能。溶血实验和体外静态血小板粘附实验显示该材料具有优良的血液相容性。该材料在生物医学领域，尤其是介入诊疗和医用薄膜产品方面有极大的应用潜力，是一种有着巨大应用前景的生物医用材料。     

碳纳米管/聚氨酯复合材料的制备及生物相容性评价

目的 制备和评价碳纳米管/聚氨酯复合材料的生物相容性。方法 通过溶胶-凝胶方法制备碳纳米管/聚氨酯复合材料,对其力学性能进行测试;根据ISO10993指南,选取溶血实验、动态凝血实验、血小板黏附实验、血小板活化实验、细胞毒性实验和材料局部植入方法对复合材料的生物相容性进行评价。结果 复合材料无明显细胞毒性,并表现出比聚氨酯材料更好的抗溶血性能、动态凝血性能、抑制血小板黏附性能以及组织相容性。结论 碳纳米管－聚氨酯复合材料具有优良的生物相容性,可以作为制备组织工程细胞生长支架、人工血管、药物载体的基础材料。     

离心型人工心脏电动叶轮血泵的左心室辅助动物长期存活试验研究

自制离心型人工心脏电动叶轮血泵在１８头小公牛身上行左心室辅助存活试验，其中有三头实验牛分别存活６２、５４、４６ｄ，试验期动物血液参数和器官功能无明显变化，证明该装置的血液相容性已经达到设计要求，动物死亡或实验终结，均由血泵内轴承磨损引起。因此，研制磁力轴承替代机械轴承，以避免机械磨损，是实现离心型人工心脏电动叶轮血泵突破性进展的关键。     

离心型人工心脏电动叶轮血泵的的左心室辅助动物长期存…

自制离心型人工心脏电动叶轮血泵在１８头小化牛身上行左心室辅助存活试验，其中有三头实验牛分别存活６２、５４、４６ｄ，试验期动物血液参数和器明显变化，证明该装置的血液相容性已经达到设计要求，动物死亡或实验终结，均由血泵内轴承磨损引起。因此，研制磁力轴承替代机械轴承，以避免机械磨损，是实现离心型人工心脏电动叶轮血泵突破性进展的关键。     

纳米碳改性聚氨酯复合材料的表面抗凝血性能

研究纳米碳改性聚氨酯聚合材料表面的血液相容性。将经过表面处理的纳米碳分散到聚氨酯体系中，制成聚氨酯／纳米碳复合薄膜。通过血小板荧光标记人全血灌注实验和羊全血体外循环等实验，观察和测定血小板在材料表面的粘附作用以及血液中血红蛋白浓度、纤维蛋白原浓度的变化，探讨纳米碳对聚氨酯抗凝血性能的影响。实验结果显示聚氨酯／纳米碳表面血小板的粘附明显低于单纯聚氨酯对照组：体外循环4h后，血液中血红蛋白浓度、纤维蛋白原浓度的变化程度减小。表明纳米碳与聚氨酯的复合可以提高材料的血液相容性。     

利用等离子体表面接枝技术提高医用聚氨酯血液相容性的研究

目的：聚氨酯作为与血液接触的植入物和组织器官替代材料在心血管系统有重要而广泛的应用前景,本研究采用等离子体表面接枝技术,通过“空间桥梁”在聚氨酯材料表面引入具有抗凝血功能的肝素分子,对材料表面的微观化学组成、表面接触角等理化性能进行了测定分析,并通过测定血小板在材料表面的粘附数量,对改性表面的抗凝血性能做了评价。结果：聚氨酯表面接枝肝素分子后,表面的氧／氮元素比提高,水接触角减小。对血小板的吸附和活化性下降,抗凝血性能得到提高。     

基于连笔直写的微结构血管支架体外测评

目的 评价基于连笔直写的生命体微结构成形技术制备的管状支架的力学性能及其生物相容性.方法 对该血管支架采用径向顺应性、缝合强度、爆破压力等力学性能检测;通过溶血率、体外动态凝血实验、血小板黏附实验进行血液相容性的分析;采用细胞培养MTT法及细胞形态学观察方法,研究其细胞相容性.结果 血管支架的径向顺应性为（4.03±0.56）%/100mmHg,缝合强度为（204.5±72.1）N/cm2,爆破压力约为（102±8）kPa;支架的溶血率为1.75%,小于ISO规定的5%;在体外动态凝血实验中,血管支架的抗凝血性能显著优于对照组载玻片（P＜0.05）,而且扫描电镜观察到血小板黏附较少,显示出该血管支架具有良好抗凝血性能;MTT比色法结果显示其细胞毒性为0～1级;细胞形态学观察显示L929细胞在该血管支架膜片的浸提液中呈梭形或三角形,贴壁良好.结论 该血管支架具有良好的力学性能、血液相容性和细胞相容性,可以满足组织工程血管支架的要求.     

Extraction of polyurethane block copolymers: effects on bulk and surface properties and biocompatibility

In order to study changes occurring in polyurethane block copolymers upon solvent extraction, a base polymer containing approximately 50% polyurethane hard segment based on 4,4'-bis(p-phenyl isocyanate), 1,4-butanediol, and poly(tetramethylene oxide) of MW 1000 was synthesized. Portions of this polymer were extracted using methanol, toluene, and acetone. Multidetector gel permeation chromatography was used to characterize the effect of extraction on molecular weight and molecular weight distribution. Extraction also affected bulk and surface properties and the blood compatibility as assessed using a canine ex vivo blood-contacting experiment. Extracted materials possessed a higher molecular weight than the base polymer and had narrower molecular weight distributions. Acetone extraction resulted in the polymer with the highest ultimate tensile strength. Contrary to expectations, the surface properties and blood compatibility of the material studied were affected minimally by extraction.     

Heparinized polyurethane surface through ionic bonding of heparin

Surface heparinization through an ionic bond is one of the methods used to improve polyurethane blood compatibility. Chains of poly(amido-amine), a tertiary aminic polymer capable of forming stable complexes with heparin, were either surface-grafted on polyurethane or interconnected with polyurethane chains using hexamethylenediisocyanate as cross-linking agent. In the latter case, a new material (PUPA) is formed with a heparin adsorbing capacity higher than poly (amido-amine) surface-grafted polyurethane. By changing the percentages of the components, different series of PUPA materials can be obtained with different physico-chemical properties. The ATR/FT-IR technique was used to characterize the new materials in the native and in the heparinized state. PUPA solution was used to coat commercial biomedical devices and they were also characterized physicochemically using ATR/FT-IR.     

一种血液相容性良好的亲水性聚氨酯材料

背景：当聚氨酯材料与活体组织相接触时,会导致一些不良反应,诸如血栓形成和炎症反应。 目的：通过混合亲水性软段来改善聚氨酯材料的亲水性,从而制得抗凝血性能较好的聚氨酯材料。 方法：以聚四氢呋喃、聚乙二醇作为混合软段,4,4’-二苯基甲烷二异氰酸酯为硬段,然后在扩链剂1,4-丁二醇以及催化剂二丁基二月桂酸锡的条件下以预聚法合成一系列聚氨酯材料。 结果与结论：增加聚乙二醇的含量,聚氨酯材料的亲水性提高。软段中含有聚乙二醇的聚氨酯材料依然能够保持聚氨酯材料优良的机械性能,血小板黏附较少,抗凝血性较好。提示通过在聚氨酯合成原料的软段中添加聚乙二醇,可以提高聚氨酯材料的亲水性和血液相容性。     

Development of Anthron, an antithrombogenic coating for angiographic catheters

A new heparinized hydrophilic polymer (Anthron) which contains a large amount of heparin ionically bound to the polymer matrix has been developed. Anthron showed excellent and long-term blood compatibility both in animal and clinical tests. It has been clarified that the long-term blood compatibility of Anthron results from its negative membrane potential and continuous release of heparin from its surface into the blood at the rate of more than 0.01 unit/cm2 min. The application of Anthron for angiographic catheters was studied, and we evaluated the effects of our antithrombogenic angiographic catheter (AAC). As controls, polyurethane catheters (PUC), and polyethylene catheters (PEC), were studied in a similar manner. In addition, the mechanisms of thrombus formation and its complications are discussed.     

Effects of implantation on the mechanical properties of the polyurethane diaphragm of left ventricular assist devices

Tensile properties of blood pump diaphragms made from a segmented polyether polyurethane (Toyobo TM5) were studied after implanting in goats for variable periods of time up to 72 days. The implantation decreased the tensile strength and ultimate elongation at break, while the elastic modulus increased very slightly. These changes in the strength and ductility were primarily caused by the contact of material with blood rather than by the mechanical fatigue of material. Mechanical stability was greatly improved by removing residual oligomers from the material by a refining procedure. The refined polyurethane has characteristics favourable for blood pump applications.     

Luminal surface microgeometry affects platelet adhesion in small-diameter synthetic grafts

One of the major problems when using small-diameter vascular grafts in arterial reconstruction is the development of platelet-rich thrombi as a consequence of blood contact with artificial surfaces. The degree of occlusion is certainly affected by the thrombogenicity of the internal surface that seems to play a key role in patency and long-term wound healing of grafts. In this study, the blood compatibility of Cardiothane (CA) vascular grafts was investigated. The CA material, a blend of polyurethane and polydimethylsiloxane that has shown relatively good physical and biocompatibility properties, was manufactured into vascular grafts by the instrument named "spray-machine". Grafts with different luminal surface porosity were produced using increasing CA concentrations by the "spray-machine" and the blood compatibility was evaluated in vitro by a circulation system in which the human blood was allowed to interact with the material in a well-controlled setting. The samples of circulating blood were collected at different times of circulation and platelet adhesion and activation were studied. Grafts with a highly porous luminal surface induced a lower adhesion and activation of platelets in vitro than the low-porosity ones. These results underlined the importance of the microgeometry of the graft luminal surface in the interaction with blood.