Make a Heart

Author:  Victor Yee

Date:  January 2008

Can hearts, or any other organ, be grown in a lab? Apparently researchers at the University of Minnesota Center for Cardiovascular Repair think so.

To accomplish this, the researchers stripped all but the basic framework of dead rat and pig hearts and "seeded" them with progenitor cells from newborn or month old rat hearts in a process called whole organ decellularization. The decellularization was done by washing the cadaveric hearts with detergents that simplified the hearts to its extracellular matrix, fibers normally holding organ cells in place.

Progenitor cells are similar to stem cells; both are undifferentiated cells capable of developing to a specialized cell, such as nerve or liver cells. True stem cells, such as those extracted from embryos are capable of unlimited self-renewal and are pluripotent. Progenitor cells, on the other hand, seem limited in self-renewal capacity and are usually unipotent or multipotent. Pluripotent cells can differentiate into any type of specialized cell; unipotent cells can differentiate into only one type of specialized cell.

Using the extracellular matrix as a guide, the researchers were able to grow the seeded cells into a structure closely resembling an actual heart. "While there have been advances in generating heart tissue in the lab, creating an entire 3-dimensional scaffold that mimics the complex cardiac architecture and intricacies has always been a mystery," said the director of the Center, Doris Taylor, Ph.D.

Hearts made in this way began contracting four days after researchers seeded decellularized hearts with the progenitor cells and began pumping eight days later under physiological load and electrical stimulation.

In addition to increasing the options of organ transplant patients, this technique offers many other potential benefits. Any organ, such as the kidney or lungs can be made in this way, and the donor cells can come directly from the recipients, significantly decreasing chances of transplant rejection and increasing chances of a faster recovery.

Written by Victor Yee

Reviewed and published by Pooja Ghatalia.