Cardiac tissue engineering: renewing the arsenal for the battle against heart disease.

The development of therapies that lead to the regeneration or functional repair of compromised cardiac tissue is the most important challenge facing translational cardiovascular research today. During the last 25 years huge efforts have been made towards restoring the physiologic functions of the heart by means of delivering cell implants into the insulted heart, initially through 'naked cell' injections and more recently through the principle of cardiac tissue engineering and the use of elaborate delivery systems and priming mechanisms that include scaffolds, bioreactors or ex vivo manipulations of cells and support structures. In this review we summarise various approaches towards cardiac repair and highlight advances in the field of tissue engineering, ranging from a review of cell types used, to advances that attempt to address mechanistic and functional elements that are critical for successful restoration of the heart, including the maintenance of the extracellular matrix through scaffoldless cardiac sheets, strategies that promote neovascularisation and the precise micro-delivery of cell populations to form three-dimensional structures through bioengineering methods such as microfabrication.