摘要
本文研究了羟基铬改性(简称改性)后的牛心包瓣组织的稳定性、力学特性和超微形态以及抗钙化性能。结果发现:(1)改性后组织的热皱缩温度由改性前(以戊二醛改性的材料)的86±0.5℃增到100℃,组织湿度和组织增厚率均减低(P<0.05);(2)单轴拉伸测试,其断裂和屈服强度都增强(P<0.05),断裂伸长率显著增加(P<0.01),而屈服伸长率和初始弹性模量则无显著差异;(3)扫描和透射电镜观察,胶原纤维间交联明显,胶原纤维和纤维束致密、均匀;(4)瓣膜试片植入大鼠皮下21天后,其组织钙含量(μg/mg干重)分别由同时植入对照试片的37.29±9.5和29.30±5.65降至3.17±0.23和2.66±0.69。结果表明,羟基铬可显著提高牛心包瓣组织的整体稳定性,增强其抗退变的能力,同时又有较好的抗钙化作用,故此种改性方法的应用很可能带来生物瓣耐久性的新突破。
Tissue-stability, mechanical properties, ultrastructure and anticalcification of bovine pericardial valve after hydroxyl chromium (HC) modification were studied. The results revealed: (1)the shrinkage temperature of HC-treated tissue(bovine rpeicardium, BP) increased from 86±0.5℃(glutaraldehyde [GA] modification) to 100℃, both tissue humidity and percentage of thickening were decreased (p<0.05); (2) uniaxial extension measurements proved that the rupture strength and yield strength of HC-treated material were improved (p<0.05),its rupture extension ratio was remarkably increased (p<0.01) but its yield extension ratio and early modulus of elasticity were not changed;(3) both scanning and transmission electron microscopical data indicated that HC-modified BP tissue showed obvious cross-linking among collagen fibers which were homogeneous and compact. Proteoglycan (PG) granules in ruthenium red stained sections were markedly decreased; (4) compared with the GA group, Ca^(2+)content (μg/mg dry wt)of subdermally implanted HC-modified BP in Wistaryoung rats was decreased from 37.29±9.50 and 29.30±5.65 to 3.17±0.23 and 2.66±0.69, respectively. The results show that HC is an excellent cross-linking agent for collagens of biological heart valve tissues, HC modification can remarkablely improve the overall stability and mechanical properties of BP so that the degradation and calcification of the valve tissue can be delayed. The application of this technique could increase the durability of bioprosthetic cardiac valves.
出处
《中国循环杂志》
CSCD
1992年第5期415-419,T017,共6页
Chinese Circulation Journal
基金
国家自然科学基金资助项目
关键词
羟基铬
牛心包瓣化学改性
防钙化
抗退变
Hydroxyl chromium
Chemical modification
Prevention of calcification
Bovine pericardial valve
Anti-degradation
