The exciting science news this week leads with a real shocker – researchers at the University of Minnesota have created a beating heart in the laboratory! This landmark achievement represents a stunning advance toward the dream of growing new organs for transplant from the patient’s own marrow stem cells.

Using a process called “whole organ decellularization,” new hearts were grown from dead rat and pig hearts from which all cells are removed, leaving only the extracellular matrix – the framework between the cells that gives form to the organ. Dr. Doris A. Taylor, head of the team that created the beating rat heart, described the guiding principle for the project -

“…give nature the tools, and get out of the way.”

The valves and outer structure scaffolding remained after the cells were removed from the cadaver hearts, then new cells were injected. Within two weeks the cells had formed a new beating heart that conducted electrical impulses and pumped a small amount of blood. Taylor told the New York Times in a telephone interview that this successful research “opens the door to this notion that you can make any organ: kidney, liver, lung, pancreas – you name it and we hope we can make it.”

To test the biological compatibility of the new hearts, the research team transplanted them into the abdomen of unrelated live rats. The hearts were not immediately rejected. A blood supply spontaneously developed, and the hearts beat regularly. Moreover, cells from the host rats then moved in and began to reline the blood vessels, even growing in the wall of the hearts!

The team is now working with pig hearts as a step toward bioengineering eventual human hearts. It is not known yet whether using the decellularized scaffolding will cause serious tissue rejection issues once the patient’s own cells colonize it. At present transplant patients must spend the rest of their lifetime on anti-rejection drugs that cause other health problems like kidney failure and high blood pressure.

Yet this research is a very big step in the right direction, and may in another decade solve the problem of limited organs available for transplant. And by using immature heart cells and adult marrow stem cells from the patient to grow the new heart, the battle over use of embryonic stem cells doesn’t factor into this major achievement. How about we take this open door and send some serious research and development dollars into expanding these projects so the benefits will more quickly become available to human patients?

Links:

NYT: Team Creates Rat Heart Using Cells of Baby Rats

Beating Heart Created in Laboratory: Method May Revolutionize How Organ Tissues are Developed

Related: Beating Heart Muscle with Built-In Blood Supply Created from Stem Cells