Thursday, November 02, 2006

Stem cell insulin offers hope to type 1 diabetics

Interesting news, since one of the main arguments that embryonic stem cell research opponents like to use is that embryonic stem cells have never been coaxed into any type of human tissue, that umbilical cord cells have the same potentential (which they do not). Obviously, I will not resolve this debate here, but I can tell you that an excellent new book examines many of the half-truths being used by embryonic stem cell opponents and debunks virtually all of them. That book is entitled "Stem Cell Wars: Inside Stories from the Frontlines" and is written by by Eve Herold.

Regardless, this is the first time that American researchers were able to coax embryonic stem cells into insulin-producing beta cells, with the idea that these could be used as replacements someday in patients with type 1 diabetes. Obviously, the fact that their first beta cells did not produce insulin in response to blood glucose remains an unresolved issue, but they are closer than researchers in Israel came about 2 years ago, when the beta cells they cultured did not produce insulin at all, so we can see this as a sign of progress!

Stem cell insulin offers hope to type 1 diabetics
October 31, 2006
From New Scientist Print Edition

Insulin-secreting cells have been created from human embryonic stem cells for the first time, raising hopes of a limitless supply of cells that could be transplanted into people with type 1 diabetes.

Emmanuel Baetge and his colleagues at Novocell in San Diego, California, used a cocktail of chemicals to coax the stem cells to form pancreatic cells (Nature Biotechnology, DOI: 10.1038/nbt1259; see

Novocell researchers say that the in vitro differentiation process mimics normal pancreatic development in the body. The engineered cells are capable of producing insulin as well as the other pancreatic endocrine hormones glucagon, somatostatin, pancreatic polypeptide and ghrelin.

The cells contain high levels of insulin similar to adult human islets and sugar-induced secretion of insulin is low, similar to that seen in early human islets. However, the cells are capable of secreting insulin in response to certain stimuli, indicating that they have many of the characteristics of functional beta cells. Baetge is confident they can overcome this problem.

"Novocell is actively investigating multiple means for maturing these cells both in vitro and in vivo," Edward Baetge, CSO of Novocell, told Scrip. "Following successful testing in diabetic animal models, Novocell will be in position to define scale up procedures for limited clinical trials. We will develop scale-up technologies and perform preclinical safety and efficacy testing over the next 2.5 years and plan to enter clinical trials in 2009." ...DELIVERY TECHNOLOGY Novocell has also developed a process to potentially deliver these cells to patients without the need for chronic immunosuppression. The company's cell encapsulation technology provides a biocompatible coating that shields the cells from the immune system.

Combining the stem cell-generated pancreatic cells with its cell encapsulation technology could transform diabetes treatment and greatly reduce medical costs, the company says. Novocell is currently conducting clinical trials examining the safety and efficacy of subcutaneous implants of encapsulated human primary islet allografts in patients with type 1 diabetes.

If they succeed, the company has also developed a way to coat the cells in a polymer called polyethylene glycol, which would prevent them from being rejected by the recipient's immune system, while allowing sugar, insulin and other signalling molecules to filter in and out.

From issue 2575 of New Scientist magazine, 31 October 2006, page 16.

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