Xi T, Liu F, Xi B
Center of Medical Devices, National Institute for the Control of Pharmaceutical and Biological Products, Beijing, China.
J Biomater Appl. 1992 Jul;7(1):61-75. doi: 10.1177/088532829200700104.
Early failures of bovine pericardial heart valves are due to leaflet perforation, tearing and calcification. Since glutaraldehyde fixation has been shown to produce marked changes in leaflet mechanics and has been linked to development of calcification, bovine pericardium fixed with the four hydrophilic epoxy formulations and their mechanical properties are studied in this paper. We measured the thicknesses, shrinkage temperatures, stress relaxations and stress-strain curves of bovine pericardiums after different treatments with (1) non-treatment (fresh), (2) glutaraldehyde (GA), (3) epoxy compounds followed by the posttreatment with GA (EP 1#, EP 2#), and (4) epoxy compounds (EP 3# and EP 4#). Results of this study showed that the hydrophilic epoxy compounds are good crosslinking agents. There are no significant differences of shrinkage temperature and ultimate tensile stress among all tissue samples pretreated with GA, EP 1# and EP 2#. However, the stress relaxations of tissue-samples pretreated with epoxy compounds followed by the posttreatment with GA (EP 1# and EP 2#) are significantly slower than that pretreated with GA, and the strains at fracture of EP 1# and EP 2# are also significantly larger than that of GA or epoxy compounds. These facts show that the bovine pericardium pretreated with the epoxy compound followed by the posttreatment with GA (EP 1# and EP 2#) possesses greater tenacity and potential durability in dynamic stress.
牛心包心脏瓣膜的早期失效是由于瓣叶穿孔、撕裂和钙化。由于已证明戊二醛固定会使瓣叶力学产生显著变化并与钙化的发展有关，本文研究了用四种亲水性环氧配方固定的牛心包及其力学性能。我们测量了牛心包在经过不同处理后的厚度、收缩温度、应力松弛和应力-应变曲线，处理方式包括：(1) 未处理（新鲜），(2) 戊二醛（GA），(3) 环氧化合物后接GA后处理（EP 1#、EP 2#），以及(4) 环氧化合物（EP 3#和EP 4#）。本研究结果表明，亲水性环氧化合物是良好的交联剂。在用GA、EP 1#和EP 2#预处理的所有组织样本中，收缩温度和极限拉伸应力没有显著差异。然而，先用环氧化合物预处理后接GA后处理（EP 1#和EP 2#）的组织样本的应力松弛明显慢于用GA预处理的样本，并且EP 1#和EP 2#的断裂应变也明显大于GA或环氧化合物处理的样本。这些事实表明，先用环氧化合物预处理后接GA后处理（EP 1#和EP 2#）的牛心包在动态应力下具有更大的韧性和潜在耐久性。
