VALIDATION OF THE SHRINKAGE TEMPERATURE OF ANIMAL TISSUE FOR BIOPROSTHETIC HEART-VALVE APPLICATION BY DIFFERENTIAL SCANNING CALORIMETRY

Shrinkage temperature is most often used to report the degree of cross -linking in glutaraldehyde-fixed animal tissue for use in bioprostheti c heart valve fabrication. Present practice utilizes the measurement o f hydrothermal shrinkage observed when a sample is subjected to a temp erature programme. This measurement at best gives a general indication of the efficiency of the treatment, i.e. the extent of cross-linking in the tissue. When differential scanning calorimetry has been used, t he ambiguity arising from the scant reporting of the protocols used do es not permit easy comparison of experimental results. This report add resses the considerations necessary to obtain optimum results in the d ifferential scanning calorimetry experiment for the determination of s hrinkage temperature in biological tissue. The shrinkage temperature o f two previously unreported tissue types, porcine pericardium and equi ne pericardium, are provided and compared with those of bovine pericar dium and porcine aortic valve leaflets.