Umbilical Cords Tapped as Rich Source of Noncontroversial Stem Cells

To capitalize on the potential of umbilical cords to be a rich source of noncontroversial stem cells, a team of cell biologists has conducted an in-depth in situ study to map the location of stem cell precursors in the cords and to develop straightforward methods for the isolation and expansion of these cells.

Investigators at the University of Pittsburgh School of Medicine (PA, USA) analyzed sections of 61-cm-long human umbilical cords that had been donated for research. For this purpose, they developed a novel in situ assay system that permitted them to analyze cells in the Wharton's jelly, the soft, hyaluronic acid rich, jelly-like intercellular substance of the umbilical cord as well as in the cords' blood vessel walls. They were seeking cells that expressed any of several mesenchymal stromal cell (MSC) markers (CD44, CD73, CD90, and CD105) as well as several progenitor and endothelial cell markers (CD146, CD34, and CD144).

They reported in the December 2009 online edition of the Journal of Biomedicine and Biotechnology that they had succeeded in determining the frequency and location of the markers and in identifying various isolation methods which yielded different cell types from the whole human umbilical cord. They showed that it was possible to isolate endothelial cells by classical methods as well as describing another method that did not require tedious removal of vessels. This method yielded a population of cells that expressed MSC markers and was capable of differentiation into multiple cell types. In addition, they developed a culturing scheme that allowed quantitative expansion of umbilical cord stromal cells that displayed a remarkably stable phenotype.

"Our experiments indicate also that at least 21 million stem cells, and possibly as many as 500 million, could be banked from a single umbilical cord after the birth of a baby," said senior author Dr. Bridget M. Deasy, assistant professor of orthopedic surgery at the University of Pittsburgh School of Medicine. "So, the cord could become an accessible source of a multitude of stem cells that overcomes many of the restrictions, such as limited quantity as well as donor age and donor sex issues that come with other adult stem cell populations."

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University of Pittsburgh School of Medicine