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Tuesday, August 26, 2008
Lab grown red blood cells from stem cells!This is big news from a big name in tissue engineering. Robert Lanza
might be considered one of the founders of tissue engineering. His company, Advanced Cell Technology in Massachussetts
and colaborators from the Mayo Clinic, have successfully produced red blood cells (erythrocytes) in culture from human embryonic
stem cells (hESCs). To do this, the researchers had to first transform the embryonic stem cells (from each of the different
blood types-all except type O negative, which is one line of ESCs not available to researchers) to a hematopoietic stem cell
which can be found in the bone marrow. Then, using various reagents and cellular cues, directed the cells to follow
completely the entire process of erythropoiesis. Not as easy as it sounds, unfortunately. The final sticking point
was to cause the red blood cell to lose its nucleus. (As a side note, without a nucleus, the red blood cell cannot divide
and thus the organism relies upon a reserve of stem cells in the bone marrow to continually create new blood cells--a red
blood cell usually only survives about 120 days before being destroyed in the spleen or liver). Without the nucleus,
the cells are able to properly transport oxygen and cannot divide, meaning they cannot become cancerous, which is one concern
of using any type of stem cell in therapy. Large numbers can be created by this method, and the need for blood donors
and the associated risks such as disease and disintegration of the blood products over time can be minimized.
 image from oncoprof.net showing the stages of erythropoiesis as wll as important growth factors that I won't describe
here for now. However, you may look at the original article's abstract from the journal Blood here
Tue, August 26, 2008 | link
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