Emoto H, Kambic H, Chen J F, Nosé Y
Cleveland Clinic Foundation, Department of Artificial Organs, Ohio 44195-5132.
Artif Organs. 1991 Feb;15(1):29-34. doi: 10.1111/j.1525-1594.1991.tb00756.x.
Five percent glutaraldehyde cross-linked gels have shown excellent blood compatibility as coatings for cardiac prostheses. A method was developed for producing thin dehydrated coatings using a proprietary dehydration procedure and ethylene oxide (EO) sterilization. The swollen surfaces of rehydrates versus wet (original) gels were compared. Within 30 min of saline rehydration, dry 30-50-microns films on textured surfaces became smooth, uniform, and comparable to original gelatin gels. Mechanical test results after rehydration showed values for strain remain unchanged (39.3 + 10.0 to 40.0 + 7.8%), but stress increased (2.79 + 1.21 to 4.22 + 1.60 dyne/cm2; p less than 0.01). The contact angle data reported gamma C values of 26.1 and 30.4 dyne/cm for original and rehydrated gels. Using a coulometric titrimeter, the measured water content of original gels was reduced from 85 to 3.4% after drying. Dried and saline rehydrated gels had a 73.2% moisture content. Gels shrank 8.8% of their original length after rehydration; however, the thickness of all pump coatings remained stable. Two-hour incubations with bovine platelet rich plasma showed no differences in platelet reactivity or morphology when compared to original gels. Light microscopy and scanning electron microscopy (SEM) showed no evidence of gel cracking or surface defects after pump endurance testing for 3 and 5 weeks. The process of dehydration eliminates the wet storage and sterility problems of such hydrogels and provides a stable film coating for a variety of blood-contacting substrates.
5%戊二醛交联凝胶作为心脏假体涂层已显示出优异的血液相容性。已开发出一种方法，使用专有的脱水程序和环氧乙烷（EO）灭菌来制备薄的脱水涂层。比较了再水化凝胶与湿（原始）凝胶的肿胀表面。在盐水再水化30分钟内，有纹理表面上30 - 50微米的干膜变得光滑、均匀，且与原始明胶凝胶相当。再水化后的力学测试结果显示应变值保持不变（39.3 + 10.0至40.0 + 7.8%），但应力增加（2.79 + 1.21至4.22 + 1.60达因/平方厘米；p小于0.01）。接触角数据报告原始凝胶和再水化凝胶的γC值分别为26.1和30.4达因/平方厘米。使用库仑滴定仪，干燥后原始凝胶的测得含水量从85%降至3.4%。干燥并经盐水再水化的凝胶含水量为73.2%。再水化后凝胶收缩了其原始长度的8.8%；然而，所有泵涂层的厚度保持稳定。与富含牛血小板的血浆孵育两小时后，与原始凝胶相比，血小板反应性或形态没有差异。光学显微镜和扫描电子显微镜（SEM）显示，在进行3周和5周的泵耐久性测试后，没有凝胶开裂或表面缺陷的迹象。脱水过程消除了此类水凝胶的湿储存和无菌问题，并为各种与血液接触的基材提供了稳定的薄膜涂层。
