Heart failure following myocardial infarction is a major cause of morbidity and mortality worldwide. The majority of muscle cells are able to regenerate and grow in event of an injury, however the heart is comprised of cardiomyocytes, and no local stem cells have been so far identified that allow this to happen. Cardiomyocytes undergo terminal differentiation soon after birth and are generally considered to be irreversibly withdrawn from the cell cycle. Therefore, upon injury, the adult heart is not able to regenerate damaged tissue which instead becomes fibrotic. A possible strategy to restore heart function after myocardial infarction is to replace or augment the damaged tissue with healthy engineered tissue. Engineered cardiac tissue could also be used to reconstruct congenital cardiac defects, and in basic cardiology research to assess the efficacy and safety of new drugs.
Using the tissue engineering chamber with the addition of a matrix and cardiomyocytes, we have been successful in generating cardiac tissue in the rat after only four weeks growth (Figure 2). This tissue is comprised of mature cardiac cells (Figure 3), that has functional properties similar to that of an adult rat’s heart. Most importantly the heart tissue beats spontaneously with its own intrinsic rhythm. These initial studies have been published in Circulation and are the basis of many ongoing studies involving cardiac tissue engineering.
Figure 1. Cardiac cells in a gel are placed in the tissue engineering chamber
Figure 2. Cardiac Tissue grown in the tissue engineering chamber at four weeks
Figure 3. Cardiac cells in the engineered tissue stained positive for desmin
