Many strategies for tissue engineering of replacement structures, such as heart valves, depend in part on preparing a tissue scaffold from a natural tissue matrix. An essential step in tissue scaffold fabrication is decellularization of the matrix. The objective of any decellularization method is twofold: (1) the preservation of the physical and biochemical properties of the extracellular matrix (ECM), and (2) the removal of all cellular material. Decellularization is currently done by contacting xenographic tissue with a combination of chemical detergents and biological agents. These processes can alter ECM structure and composition, which can trigger host immune response and inflammation. Currently, there are no accepted quantitative standards against which to certify the viability of the decellularized material. However, future standards will certainly include characteristics like removal of nuclear material, biochemical composition, and mechanical strength.
We are evaluating a novel decellularization method using liquid or supercritical carbon dioxide that will prevent tissue dehydration, remove all nuclear material from the tissue, and maintain its biochemical and mechanical integrity during the treatment process. Detergent-based decellularization processes can often take one or several days to complete, this process could potentially be completed in a few hours. Also, the CO2 process may simultaneously accomplish both decellularization and sterilization; CO2 has received considerable attention as a sterilizing agent. Success with this project will both lead to fundamental understanding of a novel decellularization process and provide a new technology for preparing natural TE scaffolds.
- Phase equilibrium for surfactant Ls-54 in liquid CO2 with water and solubility estimation using the Peng-Robinson equation of state. Pedro Tarafa and Michael A. Matthews, Fluid Phase Equilibria , 298, 212-218, 2010.
- Removing endotoxin from metallic biomaterials with carbon dioxide-based surfactant mixture. Pedro Tarafa, Eve Williams, Samir Panvelker, Jian Zhang, and Michael A. Matthews, J. Supercritical Fluids, 55, 1052-1058, 2011.
- Compressed carbon dioxide (CO2) for decontamination of biomaterials and tissue scaffolds. Pedro J. Tarafa, Aidaris Jiménez, Jian Zhang, and Michael A. Matthews. J. Supercritical Fluids, 53, 192-199, 2010.