Paolo Rossi Castelli 20 January 2022 18 min read

Type 1 diabetes: new stem cell treatments

Positive results (although there is still room for improvement) for a technique tested on 26 patients by a team of Dutch and Canadian researchers. The cells differentiate in six months and produce insulin.

One hundred years after the discovery of insulin, two studies published in the scientific journals Cell Stem Cell and Cell Reports Medicine are an important step in the search for effective treatments for type 1 diabetes. This is an autoimmune disease where the beta cells in the pancreas that produce insulin are gradually attacked and destroyed by the body’s own immune system. Now for the first time two studies have shown, that transplanting stem cells that then transform into mature beta cells can work on patients.


Insulin is of course the hormone that plays a key role in transporting glucose (sugar) from the blood to the cells in the body, which then use it to produce energy.

The first attempts to replace beta cells in the pancreas destroyed by the immune system with undifferentiated cells that could specialise and secrete insulin in a more natural way than current synthetic insulin injections, date back to 2006. However, results have never been entirely satisfactory, due to the large number of technical and clinical obstacles.

Attempts to transplant whole ‘islands’ of pancreatic beta cells also proved complex. Since then, diabetes experts at the University of Leiden in the Netherlands and the University of British Columbia in Canada have continued to study pluripotent stem cells (PSCs) derived from embryos and have managed to obtain a version that also stimulates the formation of blood vessels when transplanted, which is a vital element for treatment to work properly. The new vessels enable these cells to survive and mature into proper functioning structures.

PSCs produced excellent results in laboratory animals, leading to the selection of the first human volunteers. These are 26 patients on whom scientists wanted to check, most importantly, that the technique was safe and, secondly, for early signs that the transplanted cells were functioning properly.

Inserted under the skin

From a surgical point of view it was not particularly difficult to transplant the cells, as they are inserted under the skin. From a physiological point of view, scientists observed that cells mature within 26 weeks, differentiate and then secrete insulin in response to glycaemia, although for the moment not enough to completely eliminate the need for synthetic hormones or hypoglycaemic drugs.

However, within a year of the transplant patients were observed to need 20% less insulin and stayed within the body’s blood sugar limits 13% longer, which is an important step in the right direction.

But this is a technique that also involves a huge dose of immunosuppressants to avoid rejection (as the stem cells, although human, are not the patient’s own), with some very serious consequences in two cases.

There are still many aspects to perfect
Further tests showed that the transplanted cells were still functioning 59 weeks later, although the relative proportion of different cell types was not the same as that in the pancreas.

Nothing is known yet about the total life span of the cells. It is not clear whether PSCs die when mature, or whether they form a system that remains alive and functioning.
So for now results are not perfect. There are many aspects that need to be understood and improved like, as we mentioned above, the number of cells to be transplanted, the dose of immunosuppressants and much more. However, the results are extremely positive, as they have proved that research is headed in the right direction.



Paolo Rossi Castelli

Journalist since 1983, Paolo has been dealing with scientific divulgation for years, especially in the fields of medicine and biology. He is the creator of Sportello Cancro, the site created by on oncology in collaboration with the Umberto Veronesi Foundation. He collaborated with the pages of the Science of Corriere della Sera for several years. He is the founder and director of PRC-Comunicare la scienza.