Stem Cells: Chemistry Paves Way Toward Promising Therapies

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Stem Cells: Chemistry Paves Way Toward Promising Therapies

http://www.medicalnewstoday.com/medicalnews.php?newsid=51863

Chemists are developing new insights and techniques in an effort to

expand the therapeutic potential of stem cells, which includes

possible treatments for Parkinson's disease, diabetes, spinal cord

injury and other devastating conditions. The American Chemical

Society explored some of these latest developments, including new

findings on the transformation potential of adult stem cells, during

a special symposium, " Emerging Technologies: Stem Cells, " on Sept.

14, in San Francisco during the Society's 232nd national meeting. All

papers in this symposium were presented at the Hilton San Francisco,

Yosemite B.

Shown below are selected papers from this symposium:

Adult stem cells show wider potential than previously thought --

Embryonic stem cells are the most versatile stem cells, capable of

being transformed into any other cell type, depending on their

desired therapeutic use. Now, researchers at Northwestern University

have found new evidence that hematopoietic stem cells, a type of

adult stem cell derived from the bone marrow that gives rise to blood

cells, is capable of undergoing more diverse transformations than

previously thought and could be transformed into a wide variety of

tissue types, not just blood cells. In recent laboratory tests, human

megakaryocytes (bone marrow cells that produce blood platelets that

are responsible for blood clotting) derived from adult hematopoietic

stem cells were, for the first time, reprogrammed into neutrophil-

like cells similar to the white blood cells that are responsible for

fighting infections, according to study leader E. Terry Papoutsakis,

Ph.D., a chemical engineer at the University. Insights from this

study could help guide similar adult stem cell transformations in

other cell types in the future, he says. (BIOT 459, Sept. 14.)

Elasticity of tissue environment plays role in determining stem cell

growth --Researchers at the University of Pennsylvania have shown

that the elasticity of a stem cell's environment is a major

determinant of what type of tissue the stem cell becomes. In

laboratory tests, Dennis Discher, Ph.D., and Adam Engler, Ph.D., grew

mesenchymal stem cells (derived from adult bone marrow) in polymer

hydrogels with either soft, medium or rigid elasticity. Based on

resulting cell shapes as well as messenger RNA and protein markers,

stem cells grown in softer environments -- such as brain tissue --

tended to produce nerve-like cells; those grown in environments with

medium elasticity -- similar to muscle -- produced muscle-like cells;

and stem cells grown in more rigid environments -- like bone --

produced bone-like cells. The study provides new clues on how

chemical and mechanical factors interact to influence stem cell

growth, the researchers say. (BIOT 463, Sept. 14).

'Stretched' stem cells have potential to be transformed into blood

vessel cells -- Scientists have searched for years for a renewable

cell source to craft blood vessels that can be used for heart bypass

surgery and perform more like natural arteries. Now, researchers at

the University of California, Berkeley, have shown that mesenchymal

stem cells from adult bone marrow can be repeatedly and mechanically

stretched -- in a manner similar to a taffy pull -- into patterns

that could potentially transform them into smooth muscle cells

similar to blood vessel tissue. These newly-formed smooth muscle

cells, which can expand and contract, could be used as a component of

a tissue-engineered graft that may provide superior performance over

conventional grafts that are used for bypass surgery, says study

leader Kurpinkski, a doctoral candidate in the University's

Department of Bioengineering. (BIOT 464, Sept. 14).