Synergistic effect of released aspirin/heparin for preventing bovine pericardial calcification

Calcification is a frequent cause of the clinical failure of bioprosthetic heart valves fabricated from glutaraldehyde pretreated bovine pericardium ( GATBP). Aspirin, a potent antiplatelet drug, and heparin, an anticoagulant, are commonly used for postimplant complications such as thrombosis and thr omboembolism. Aspirin and heparin were embedded in chitosan/polyethylene vi nylacetate co-matrix to develop a prolonged release form. The effect of the se drugs towards the bioprosthetic calcification was investigated by in vit ro and in vivo models. In vitro and in vivo evaluation suggest that the rel eased aspirin/heparin from the co-matrix had a synergistic effect in inhibi ting GATBP calcification. In vivo subcutaneous coimplantation was performed with PEG-20,000 grafted bovine pericardium (PEG-GABP), aspirin, and hepari n. Biochemical, histological, and scanning electron microscopic evaluation of retrieved samples demonstrated a significant reduction in calcium deposi tion and alkaline phosphatase activity on PEG-GABP compared to GATBP. It se ems that the aspirin/heparin combination synergistically inhibits the peric ardial calcification in addition to their antithrombotic function.