Abstract 275: In Vitro Inflammatory Assays for Decellularized Xenogeneic Heart Valves

Abstract

Intro: There is great interest in a decellularized xenogeneic heart valve for valve replacement due to the shortage of human tissue available for implant. However, decellularized xenografts have a poor clinical history due to incomplete antigen removal. The inflammatory potential of decellularized heart valves can be evaluated in vitro using assays that measure antigen presence and cytokine production by cultured human macrophages. This study tests the inflammatory potential of porcine aortic valves before and after decellularization. Methods: Decellularization was confirmed by histology and DNA quantification. Enzyme linked immunosorbent assays (ELISAs) tested for inflammatory potential using pooled human serum as a primary antibody. Additional tissue samples were cultured with THP-1 derived macrophages and the production of monocyte chemoattractant protein-1 (MCP-1) was measured. Results: Decellularization resulted in 99% removal of DNA. The decellularized valve conduit was found to be 2.49% as inflammatory as native tissue (Figure 1). Human macrophages cultured with native tissue produced approximately 10-fold more MCP-1 compared to decellularized tissue. Impact: The in vitro assays described quantify a reduced inflammatory response for decellularized heart valves. Future use of these assays can be used to further decrease the inflammatory potential, increasing the safety of decellularized xenogeneic heart valves.