IN-VITRO STUDY OF ENZYMATIC DEGRADATION OF BIOLOGICAL TISSUES FIXED BY GLUTARALDEHYDE OR EPOXY COMPOUND

The study, using bacterial collagenase, was to investigate the changes in characteristics of a collagen-rich tissue, porcine pericardium, fi xed by glutaraldehyde or epoxy compound (ethylene glycol diglycidyl et her) during the course of degradation. Fresh porcine pericardium was u sed as a control. During degradation, the heat released by the reactio n of collagenase with a test sample was monitored by a highly sensitiv e microcalorimeter. Also, the degree of degradation of each test sampl e was determined by measuring its increment in free amino group conten t and changes in denaturation temperature and tensile strength. Microc alorimetric analysis of collagenase degradation of fresh, epoxy-fixed, and glutaraldehyde-fixed tissues revealed that the heat released duri ng degradation correlates well with the degree of tissue degraded. The cleaving of peptide bonds in biological tissue by collagenase degrada tion may increase its free amino group content and reduce its denatura tion temperature and tensile strength. It was noted that the fresh tis sue cannot resist bacterial collagenase degradation, while the glutara ldehyde fixed tissue had a relatively better resistance to degradation than its epoxy-fixed counterpart.