The effect of heparin hydrogel embedding on glutaraldehyde fixed bovine pericardial tissues: Mechanical behavior and anticalcification potential

Heart valve diseases remain common in industrialized countries. Bioprosthetic heart valves, introduced as free of anticoagulation therapy alternatives to mechanical substitutes. Still they suffer from long term failure due to calcification. Different treatment methods introduced to inhibit calcification, have so far been limited in success. Glycosaminoglycans (GAGs) possess properties including high negative charge, anticoagulation and anti-inflammatory activity that make them a potential solution for calcification problem. In this study, heparin hydrogel was prepared and characterized both chemically and mechanically. After that, heparin hydrogel embedded bovine pericardial tissues, fixed with glutaraldehyde, were produced and tested for their mechanical behavior and anticalcifcation potential in vitro using the constant composition model. In the calcification experiments, tissues were divided into three groups: a) Controls without treatment, b) Hydrogel treated tissues and c) Tissues with raw heparin dissolved in the calcification solution. The results showed that embedding of tissue with hydrogel had no stiffening effect on its mechanical behavior. Calcification assessment showed a significant efficacy on inhibition of calcium phosphate deposition of hydrogel treated (second group) in comparison to untreated tissues (control, first group). Calcification inhibition potential was very similar in both the second and raw heparin (third group). Histological data confirmed the obtained results, suggesting that heparin treatment is a promising anticalcification agent.