Stem Cells and Type 1 Diabetes: Insights into the Research Landscape

Researchers are continuously exploring new investigational treatments for type 1 diabetes aimed at improving the quality of life of people living with this condition. In a previous blog, we provided a brief overview of these investigational therapies, offering you a starting point to understand the fundamentals of these approaches and how they work.

In this blog, we will take a closer look at one of these approaches: stem cell treatment for type 1 diabetes.  We’ll dive deeper into what stem cells are, how they work, and what progress researchers are making in this field. 

What Causes Type 1 Diabetes?  

In Type 1 Diabetes (T1D), the body’s immune system attacks and destroys the beta (β) cells in the pancreas, which are responsible for producing insulin. Insulin is a hormone that helps sugar (glucose) move from your blood into your cells, where it can be used for energy. Without enough insulin, glucose remains in the blood, leading to high blood sugar levels and depriving cells of the energy they need to function properly.¹ ​

How is Type 1 Diabetes currently treated? 

The current standard treatment for type 1 diabetes involves lifelong insulin administration to regulate blood sugar levels. With the objective of replacing β cells and eliminating the need for daily insulin, doctors may consider a pancreas transplant from a donor, or a transplant of just the insulin-producing cells (an investigational procedure called pancreatic islet transplant). ​^{2, 3​}

However, there are significant challenges with these treatments for diabetes: 

• Insulin treatment is a lifelong necessity. It is part of effective management of the disease, alongside other lifestyle adjustments. ​^{1, 2, 3​}  

• Whole pancreas transplant is a complex procedure, there is a limited supply of donor organs, and both whole pancreas and pancreatic islet transplants need lifelong immunosuppression. Additionally, islet transplant remains experimental.  ​^{2, 3​}

Researchers are investigating potential new treatments for diabetes with the objective of preventing or reversing the disease, and one area of growing interest is the use of stem cells to create new insulin-producing β cells. 

What Are Stem Cells and What Do They Do? 

Stem cells are special cells in the body that have two unique abilities: 

1. They can make copies of themselves indefinitely.
2. Depending on where the stem cells are, they can transform into different types of cells such as muscle cells, brain cells, or β cells.

These qualities make them fundamental for maintaining and repairing tissue and also make them of interest for researchers to treat different types of conditions, including type 1 diabetes. ​^{4, 5} 

How could Stem Cells help treat Type 1 Diabetes? 

Researchers of type 1 diabetes aim to create insulin-producing β cells from stem cells to replace those destroyed by the disease. These cells could be potentially transferred into the body, with the aim that the person would no longer need to take insulin. ⁵ 

However, several challenges remain, including identifying which type of stem cells work best for people, where in the body these new cells should be placed, and how to protect them from the immune system, which could attack them in the same way it attacked the original b cells. ​^{4, 6​} Right now, stem cell treatment for type 1 diabetes is still investigational, and clinical trials are ongoing to test safety and effectiveness. 

Q1: What type of stem cells can be used? 

Various types of stem cells could be used to treat type 1 diabetes. Each type of stem cell has advantages and limitations, and research is ongoing to determine the most effective approach for the treatment of type 1 diabetes. Stem cell types include: 

• Embryonic stem cells. These stem cells are the most versatile, capable of developing into any cell type, including insulin-producing β cells. However, their use raises ethical concerns because they come from early-stage human embryos. Guidelines from the National Institutes of Health (NIH) state that these cells can only be used if they come from embryos created through in vitro fertilization (IVF) for reproductive purposes, which are no longer needed for this purpose, and are donated to research with the informed consent from donors.​ ^{4​, 7} 

• Adult stem cells. Found in small numbers in various adult tissues, such as bone marrow and fat, these stem cells can only transform into specific cell types related to their tissue of origin. Consequently, their ability to become insulin-producing cells is more limited compared to embryonic stem cells.​^{4, 5} 

• Adult cells reprogrammed to act like embryonic stem cells. Scientists are now able to take adult cells, such as skin cells, and alter or “reprogram” them to behave similarly to embryonic stem cells.  While this approach may help address ethical concerns surrounding the use of embryonic stem cells in the treatment of type 1 diabetes, it presents its own challenges. Reprogrammed adult cells may not transform into every type of cell needed as easily as embryonic stem cells and are more likely to carry irregularities or genetic damage that has accumulated over time. ​^{4, 5}  

Q2: How can implanted cells be protected from the immune system? 

Regardless of which type of stem cells are implanted, recipients’ bodies may recognize them as foreign and attack them. In type 1 diabetes, not only are these foreign cells, and therefore prime targets for any immune system, but they are also administered to people whose bodies have a track record of specifically attacking β cells. ^​6 To protect these cells from the immune system, researchers are exploring combining stem cell treatment with other approaches: 

1. Immunosuppressive drugs 

The simplest way to protect implanted cells from immune destruction is to use immunosuppressive drugs, which prevents the immune system from attacking them. ⁶  However, this requires lifelong use of immunosuppressive medication, which can have side effects and make the body more vulnerable to infections. ⁶   

In October 2024, a phase 1/2 clinical trial using stem cells and immunosuppressive drugs announced that a number of participants with type 1 diabetes began to produce insulin after receiving an infusion of insulin-producing cells derived from stem cells, combined with immunosuppressive therapy. ​^{8, 9}​ Whilst this study showed some patients were able to reduce or stop their insulin use, further research is needed to fully understand the long-term safety and effectiveness of this new investigational diabetes treatment. ​^{5, 6} 

2. Encapsulation 

This approach aims to protect the implanted cells without the need for immunosuppressive drugs. In this method, a physical barrier surrounds the cells to shield them from the immune system. ​^{6, 10}

​There are two main methods being explored:  

• Macroencapsulation. This involves placing the cells inside a small device in the body that acts as a physical barrier against the immune system. Whilst the device can be removed if complications arise, it may also limit the cells’ access to essential nutrients, oxygen, and blood. ¹⁰​ Additionally, the body may recognize the device as foreign and trigger an immune response. ​^{6, 10, 11}

• Microencapsulation. In this method, cells are coated in a protective gel that aims to prevent immune cells from attacking them. ​^{6, 12​} While microencapsulation provides a larger surface area for better oxygen and nutrient transfer, the protective gel may still prevent direct contact with blood vessels, which can limit the cells’ ability to function.​^10​ Removing the cells if issues arise is also more challenging, and the body may still recognize the encapsulation material as foreign and attack it. ​^{10, 11}

Macroencapsulation and microencapsulation are currently being tested in diabetes stem cell treatment trials in phase 1/2, with additional studies in pre-clinical development.​ ^{12, 13} Researchers are exploring new materials, such as hydrogels, alginate-based coatings, and biocompatible polymers, which are designed to improve the exchange of oxygen and nutrients. Furthermore, new nanoporous and semi-permeable membrane designs are being tested to allow better communication between the implanted cells and the bloodstream. These innovations aim to improve the long-term function of the implanted cells and reduce the need for immunosuppressive drugs to prevent immune rejection.​^{6​, 11, 12}​

3. Genetic modification 

An alternative to physically shielding implanted cells from the immune system is to genetically modify them to evade immune detection. ^6​ However, one concern with genetically modified cells is that if they become infected or start dividing uncontrollably— which can potentially lead to cancer — the immune system may not be able to detect and eliminate them. To mitigate this risk, researchers are exploring the use of “protective control genes,” which would trigger the cells to self-destruct in response to specific signals, ensuring they can be safely removed if necessary.^6​​ While there have been some studies in mice using genetically modified stem cells, research in humans is still in the early stages. ​^{2, 14​}  

These different protective techniques could potentially be combined to maximize protection to implanted cells. At the time of writing, the first human clinical trial is currently testing the safety and tolerability of genetically modified cells that have been placed in a protective device.^{​2, 14}

Q3: Where to implant cells 

While the pancreas is the natural home for β cells, researchers are exploring other potential locations in the body where these cells could function effectively. The key requirement for β cells to work is good access to the bloodstream, as they need to receive nutrients and release insulin into the blood.​​⁶ So far, researchers have experimented with various subcutaneous (under the skin) locations and are also investigating the flap of fatty tissue that surrounds the intestines.​⁶

Each bodily site has its advantages and disadvantages for the treatment of type 1 diabetes. For example, different areas vary in their ability to support the growth of new blood vessels around the implanted cells or devices (vasculature), their capacity to hold the devices, and how well they tolerate multiple implantations if the cells need replacing. Additionally, comfort for the patient is a significant factor when determining the ideal location for these implants.​⁶

Conclusions 

Stem cells have the unique ability to make copies of themselves and transform into different types of cells. In the research for type 1 diabetes treatment, they could potentially be used to generate healthy insulin-producing cells, replacing those destroyed by the immune system. However, there are still several challenges to overcome. Scientists are working to identify the most suitable type of stem cells to generate new insulin-producing cells and the best location for their placement. Protecting the newly generated β cells from the immune system is also an important issue, as the body could attack them just as it did the original β cells. Potential solutions include immunosuppressive medications, encapsulation techniques to shield these cells, and genetic modifications to make them less visible to the immune system. Ongoing studies, including clinical trials, are focused on addressing these challenges, and further research is required to determine the most effective strategies.  

Visit this page to learn more about clinical trials in type 1 diabetes:   

At myTomorrows, we have a team of Patient Navigators with medical background, and are multi-lingual professionals, to help you explore your treatment options and support you through your journey.   

If you are affected by type 1 diabetes and want to explore clinical trial options with your physician, you can book a call with a Patient Navigator to discuss your options and learn more about participating in clinical trials.