Riboflavin photo-cross-linking method for improving elastin stability and reducing calcification in bioprosthetic heart valves.

Glutaraldehyde cross-linked bioprosthetic heart valves might fail due to progressive degradation and calcification.In this study, we developed a new BHVs preparation strategy named as "HPA/TRA/FMN" that utilized 3,4-hydroxyphenylpropionic acid (HPA)/tyramine (TRA) conjugated pericardium and riboflavin 5'-monophosphate (FMN) initiated photo-cross-linking method. HPA/TRA-pericardium conjugation would provide extra phenol groups for FMN initiated photo-cross-linking.The feeding ratio of riboflavin 5'-monophosphate was optimized. The collagenase and elastase enzymatic degradation in vitro, biomechanics, calcification, elastin stability in vivo, and macrophage marker CD68 were characterized. We demonstrated that riboflavin photo-cross-linked pericardiums had great collagen and elastin stability, improved mechanical properties, better resistance for calcification, and less CD68 positive macrophages in rat subdermal implantation study.This new riboflavin photo-cross-linking strategy would be a promising method to make BHVs which have better elastin stability, less calcification, and reduced inflammatory response.