Sung H W, Cheng W H, Chiu I S, Hsu H L, Liu S A
Department of Chemical Engineering, National Central University, Chung-Li, Taiwan, Republic of China.
J Biomed Mater Res. 1996 Fall;33(3):177-86. doi: 10.1002/(SICI)1097-4636(199623)33:3<177::AID-JBM7>3.0.CO;2-N.
Bioprostheses derived from collagenous tissues have to be fixed and subsequently sterilized before they can be implanted in humans. Clinically, the most commonly used fixative is glutaraldehyde. However, the tendency for glutaraldehyde to markedly alter tissue stiffness and promote tissue calcification are well-recognized drawbacks of this fixative. To address the deficiencies with the glutaraldehyde-fixed tissue, a new fixative, epoxy compound, was used to fix biological prostheses. The study was undertaken to investigate the fixation rates and crosslinking densities of biological tissues fixed with various epoxy compounds. These epoxy compounds are different in their chemical structures. Glutaraldehyde was used as a control. The fixation rates and crosslinking densities of the fixed tissues were determined by measuring their fixation indices and denaturation temperatures, respectively. Generally, the epoxy-fixed tissues were more pliable than the glutaraldehyde-fixed one. Furthermore, the tissues fixed with monofunctional epoxy compound were more pliable than those fixed with multifunctional epoxy compounds. With increasing pH or temperature, the fixation rate of epoxy compound increased. However, the number of epoxide functional groups did not seem to affect the fixation rate of the epoxy compound. The fixation rate of glutaraldehyde was faster than that of epoxy compounds. Additionally, the crosslinking density of the glutaraldehyde-fixed tissue was greater than that of the epoxy-fixed counterparts. Moreover, it was noted that the denaturation temperatures of the tissues fixed with glutaraldehyde or multifunctional epoxy compounds were significantly higher than the fresh ones (p < 0.05), while that fixed with monofunctional epoxy compound stayed roughly the same throughout the entire fixation process (p > 0.05). The results obtained in this study may be used to optimize the fixation process for developing bioprostheses fixed with epoxy compounds.
源自胶原组织的生物假体在植入人体之前必须进行固定并随后灭菌。临床上，最常用的固定剂是戊二醛。然而，戊二醛明显改变组织硬度并促进组织钙化的倾向是这种固定剂广为人知的缺点。为了解决戊二醛固定组织的缺陷，一种新型固定剂——环氧化合物被用于固定生物假体。本研究旨在调查用各种环氧化合物固定的生物组织的固定率和交联密度。这些环氧化合物的化学结构不同。以戊二醛作为对照。通过分别测量固定指数和变性温度来确定固定组织的固定率和交联密度。一般来说，环氧化合物固定的组织比戊二醛固定的组织更柔韧。此外，单官能环氧化合物固定的组织比多官能环氧化合物固定的组织更柔韧。随着pH值或温度升高，环氧化合物的固定率增加。然而，环氧官能团的数量似乎并不影响环氧化合物的固定率。戊二醛的固定率比环氧化合物快。此外，戊二醛固定组织的交联密度大于环氧化合物固定组织的交联密度。而且，值得注意的是，用戊二醛或多官能环氧化合物固定的组织的变性温度显著高于新鲜组织（p<0.05），而用单官能环氧化合物固定的组织在整个固定过程中大致保持不变（p>0.05）。本研究获得的结果可用于优化用环氧化合物固定的生物假体的固定工艺。
