Mending a broken heart

The problem
HEART DISEASE IS a blanket term for any illness that causes the cardiac muscles to lack circulation (coronary heart disease) or to weaken (cardiomyopathy). Traditional medicine can only help patients cope with a weakened heart. However, techniques in cell therapy may one day allow doctors to direct special cells to regenerate tissue and repair heart damage through stem cell transplantation.
Unfortunately, stems cells are hard to come by and their use in clinics is strictly regulated. To make matters worse, cells taken from patients with cardiovascular disease are often dysfunctional. There is a desperate need for alternative cell therapies for tissue regeneration.

The researcher
Erik Suuronen is the director of the Cardiovascular Tissue Engineering Lab at the University of Ottawa Heart Institute. Suuronen wants to use stems cells and tissue engineering to treat heart disease. He hopes that one day these cell therapies will allow patients to regenerate new muscle and blood vessels rather than live their lives with chronic disease.

The project
Therapeutic cells already exist in the body, called progenitor cells. Rather than transplanting cells to the weakened muscle, Suuronen’s research aims to attract the body’s own progenitor cells to perform the repair and cause tissue regeneration. Normally, only a small number of these cells reach the damaged tissue, but if the target site could be encouraged to attract more of them then the progenitor cells would mobilize to repair and regenerate damaged tissue.

The key
Suuronen has developed a matrix of collagen (collagen is a common extracellular protein) and a complex sugar called sialyl LewisX. Sialyl LewisX instructs the progenitor cells to attract more therapeutic cells and regenerate the damaged tissue while the collagen acts as a “smart” scaffold that supports them during the repair.
Suuronen injected the enhanced matrix into the thigh muscles of rats with damaged blood vessels and dying muscles. The enhanced matrix recruited progenitor cells from the rats’ bone marrow into the bloodstream, leading them to the damaged site. The recruited cells then grew into new blood vessels and galvanized muscle regeneration. By successfully stimulating new muscle growth to replace lost tissue, this research suggests that heart damage could one day be repaired through cellular therapy.