Validation of the shrinkage temperature of animal tissue for bioprosthetic heart valve application by differential scanning calorimetry.

This research investigates a better method of measuring the extent of cross-linking in glutaraldehyde-fixed animal tissue used in bioprosthetic heart valve production, using differential scanning calorimetry, and tests the method on two previously unreported tissue types, porcine pericardium and equine pericardium.

Background

• Shrinkage temperature is commonly used to denote the level of cross-linking in glutaraldehyde-fixed animal tissue used for developing bioprosthetic heart valves. Cross-linking refers to the process where polymer chains are linked together, which is essential for the tissue’s mechanical stability and bio-function.
• Current techniques measure hydrothermal shrinkage when a tissue sample is exposed to certain temperature regimes, which provides an overview of the treatment’s effectiveness, specifically the level of cross-linking in the tissue.
• Differential scanning calorimetry (DSC), a thermoanalytical technique used to measure the amount of energy absorbed or released by a sample when it is heated or cooled, has been used in this context. However, due to vague reporting of protocols used in DSC, it is difficult to compare experimental outcomes.

Purpose and Methodology

• The focus of the study is to provide methodology considerations required to get the most accurate results in determining shrinkage temperature in biological tissue using DSC. These considerations may help in standardizing the experimental protocols and comparing results more accurately.
• Moreover, the study also ventures into reporting shrinkage temperatures of two new types of tissues: porcine pericardium and equine pericardium, drawing comparisons with known results from bovine pericardium and porcine aortic valve leaflets.

Implications

• The results should help improve the quality of bioprosthetic heart valves and reduce discrepancies in research results by providing a standardized protocol for DSC in measuring shrinkage temperatures.
• Exploring new types of tissues for heart valve application could potentially broaden the possible sources or improve the effectiveness of these bioprosthetic valves.