The expectations generated by the Edmonton protocol in 1999 do not seem to have been met, despite the effort of multiple researchers in advancing in this technique of pancreatic islet transplantInsulin.

Meanwhile, stem cell research has advanced considerably in the preclinical field, although at this point almost no one dares to put a term to the jump to the clinic.

One of the greatest experts in Spain in regenerative medicine applied to diabetes, Ramón Gomis, director of the August Pi I Sunyer Biomedical Research Institute (IDIBAPS), from Barcelona, ​​summarizes in a nutshell the effects of this treatment: "Revert the diabetes, but the effect lasts very little. "

The truth is that this route has not been fully abandoned, as exposed by the authors of a recently published review in Stem Cells International.

Thomas Linn and his collaborators of the University of Giessen (Germany) describe the progressive improvement of the initial protocol, which has been translated not only into a delay of the return to insulin injections, but also in a reduction in the necessary body pancreasfor each transplant and in a decrease in the secondary complications of type 1 diabetes, such as retinopathy, neuropathy or macrovascular problems.

Advances have also been registered regarding the required immunosuppression, although, as with the rest of the transplant modalities, we are still very far from being able to do without it.

A European project, called elastislet, investigates the encapsulation of beta cells of insulin producers inside capsules designed from innovative materials in order to curb the immune response after transplantation.

pitfalls and alternatives

But the need for long -term immunosuppression is only one of the pitfalls listed by the Thomas Linn team in its review.

It is also necessary to consider the shortage of body organs, the risk of attack of the islets transplanted by components of the innate immune system, the need for delay due to the low regenerative capacity of the islets and the return to the administration of insulin after betweenone and five years.

For all these reasons, the German group proposes the search for other potentially definitive treatments for type 1 diabetes, among which the use of stem cells stands out.

Gomis confirms that cell therapies research is in full boiling: "Very interesting results are being achieved and at some point the spark will jump."

However, he is prudent and recognizes that many obstacles must be overcome and "spin very fine to move on to humans."For example, a crucial aspect is homogeneity, which is reflected in the importance of "cells being identical in the ability to respond to the hypoglycemic environment."

Another key issue is revascularization, that is, "inducing an adequate vascular bed" for transplanted cells, since insufficient revascularization leads to the death of cells by apoptosis.

The Gomis team works intensely both in the field of revascularization and in the cell differentiation protocols."We have managed to go directly from human fibroblast to insulin producing cell, without the intermediate phase of obtaining induced pluripotentiality cells (IPS)."

With regard to the most appropriate stem cell type, Thomas Linn and their companions opt for mutipoting adult stem cells because "they can be extracted from the patient, they are less prone to malignization than embryonic stem cellsand they have already started successfully clinical trials with them ".

"We are moving forward," concludes Gomis, but not as fast as expected at first."Many scientists believed that regenerative medicine was just around the corner."

Search for drugs

Clinical applications are still far away, but the results of the abundant studies that are published in high -impact magazines can have a much more immediate utility: the development of animal models that allow to test in a much more accurate way efficiency and safetyof the new drugs to combat diabetes.

This could be the fate of the advances achieved by Douglas Melton, of the Harvard University stem Cell Institute, in the United States, and its team.The work published a week ago in Nature Communications shows that beta cells obtained from cells of patients with type 1 diabetes are functional in mice.

The researchers obtained fibroblasts from three diabetics, differentiated them in beta cells and transplanted them in a Murino model, where they deployed their primary functions: the production of insulin and the regulation of blood glucose levels.These results were maintained over several months and the cells derived from patients passed the comparison test - both in vitro as in vivo - with normal insulin producing cells.Now it will be necessary to expand the number of samples of affected so that the diversity of the pathology is reflected.