University of Minnesota researchers recently announced that they have created a beating heart in the laboratory. This may sound like the stuff of a Philip K. Dick science-fiction novel - but it’s a real breakthrough in regenerative medicine.
The researchers used a detergent to remove cells from a dead rat heart, leaving behind only the nonliving fibers that give the heart its shape: a white, rubbery, 3-D structure called the extracellular matrix. This biological scaffolding allows cells to attach and grow into functioning tissue and gives the heart muscle something to pull against.
Scientists then injected cells from neonatal and newborn rats’ hearts into the left ventricle of this extra-cellular matrix and pumped oxygen and nutrients through the structure of blood vessels to support cell growth. Eight days later, the hearts were pumping.
The new technique is called whole organ decellularization – and the hope is that researchers might soon be able to replicate this success for human transplants. By facilitating organ growth from a recipient’s own stem cells, decellularization could help overcome a major impediment to transplants today: the need for organ tissue that is immunologically compatible with the recipient’s own. The schedule for human trials is not yet clear, but very much in demand: in the United States alone, 5 million people live with heart failure, roughly 50,000 of whom die each year while awaiting a transplant.1