components from a heart is perfusion decellularization. This technique involves perfusing the heart with detergents such as SDS and Triton X-100 dissolved in distilled water. The remaining ECM is composed of structural elements such as collagen, laminin, elastin and fibronectin. The ECM scaffold promotes proper cellular proliferation and differentiation, vascular development, as well as providing mechanical support for cellular growth. Because minimal DNA material remains after the decellularization process, the engineered organ is biocompatible with the transplant recipient, regardless of species. Unlike traditional transplant options, recellularized hearts are less immunogenic and have a decreased risk of rejection. Once the decellularized heart has been sterilized to remove any pathogens, the recellularization process can occur. Multipotent cardiovascular progenitors are then added to the decellularized heart and with additional exogenous growth factors, are stimulated to differentiate into cardiomyocytes, smooth muscle cells and endothelial cells. Recellularized heart functionality The most promising results come from recellularized rat hearts. After only 8 days of maturation, the heart models were stimulated with an electrical signal to provide pacing. The heart models showed a unified contraction with a force equivalent to ~2% of a normal rat heart or ~25% of that of a 16-week-old human heart. Although far from use in a clinical setting, there have been great advances in the field of bioartificial heart generation. The use of decellularization and recellularization processes, has led to the production of a three dimensional matrix that promotes cellular growth; the repopulation of the matrix containing appropriate cell composition; and the bioengineering of organs demonstrating functionality (limited) and responsiveness to stimuli. This area shows immense promise and with future research may redefine treatment of end stage heart failure. References Cardiology Tissue engineering