EGCG and enzymatic cross‐linking combined treatments for improving elastin stability and reducing calcification in bioprosthetic heart valves

The failures of glutaraldehyde (GLUT) cross‐linked bioprosthetic heart valves (BHVs) are mainly due to degeneration and calcification. In this study, we developed a new preparation strategy for BHVs named as “HPA/EDC/EGCG” that utilized 3,4‐hydroxyphenylpropionic acid (HPA)‐conjugated pericardium, epigallocatechin gallate (EGCG), and horseradish peroxidase (HRP)/hydrogen peroxide (H 2 O 2 ) enzymatic cross‐linking. HPA–pericardium conjugation was done by carbodiimide coupling reaction using 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide (EDC) and N ‐hydroxysuccinimide (NHS). Then HPA‐conjugated pericardium was cross‐linked by HRP/H 2 O 2 enzyme‐catalyzed oxidation. The feeding ratios of HPA and EGCG were optimized. The consumption of amino groups, collagenase and elastase degradation in vitro , biomechanics, extracellular matrix stability, and calcification of HPA‐/EDC‐/EGCG‐treated pericardiums were characterized. We demonstrated that HPA‐/EDC‐/EGCG‐treated pericardiums had better elastin stabilization and less calcification. EGCG and enzymatic cross‐linking treated pericardiums showed improved mechanical properties. This new EGCG and enzymatic cross‐linking strategy would be a promising method to make BHVs with better elastin stability and anti‐calcification property.