Scientists create functional 3D-printed human islets for type 1 diabetes treatment

A team of international scientists has made a major leap forward in diabetes research by successfully 3D printing functional human islets using a novel bioink. Presented today at the ESOT Congress 2025, the new technology could pave the way for more effective and less invasive treatment options for people living with type 1 diabetes (T1D).

The breakthrough involved printing human islets—the insulin-producing clusters of cells in the pancreas—using a customized bioink made from alginate and decellularized human pancreatic tissue. This approach produced durable, high-density islet structures that remained alive and functional for up to three weeks, maintaining strong insulin responses to glucose and showing real potential for future clinical use.

Traditional islet transplants are typically infused into the liver, a process that can result in significant loss of cells and limited long-term success. In contrast, the 3D-printed islets in this study were designed to be implanted just under the skin, a simple procedure requiring only local anesthesia and a small incision. This minimally invasive approach could offer a safer and more comfortable option for patients.

“Our goal was to recreate the natural environment of the pancreas so that transplanted cells would survive and function better,” explained lead author Dr. Quentin Perrier. “We used a special bioink that mimics the support structure of the pancreas, giving islets the oxygen and nutrients they need to thrive.”

To keep the fragile human islets safe during printing, the team created a gentler way to print by fine-tuning key settings—using low pressure (30 kPa) and a slow print speed (20 mm per minute). This careful approach reduced physical stress on the islets and helped keep their natural shape, solving a major problem that had held back earlier bioprinting attempts.

In laboratory tests, the bioprinted islets stayed alive and healthy, with over 90% cell survival. They also responded better to glucose than standard islet preparations, releasing more insulin when it was needed.

By day 21, the bioprinted islets showed a stronger ability to sense and react to blood sugar levels—an important sign that they could work well after being implanted. Importantly, the constructs maintained their structure without clumping or breaking down, overcoming a common hurdle in earlier approaches.

Additionally, the 3D-printed structures featured a porous architecture that enhanced the flow of oxygen and nutrients to the embedded islets. This design not only helped maintain cell health but also promoted vascularization, both of which are critical for long-term survival and function after transplantation.

“This is one of the first studies to use real human islets instead of animal cells in bioprinting, and the results are incredibly promising,” noted Dr. Perrier. “It means we’re getting closer to creating an off-the-shelf treatment for diabetes that could one day eliminate the need for insulin injections.”

The team is now testing the bioprinted constructs in animal models and exploring long-term storage options, such as cryopreservation, that could make the therapy widely available. They are also working on adapting the method for alternative sources of insulin-producing cells to overcome donor shortages, including stem-cell-derived islets and xeno-islets (from pigs).

“While there is still work to be done, this new bioprinting method marks a critical step toward personalized, implantable therapies for diabetes. If clinical trials confirm its effectiveness, it could transform treatment and quality of life for millions of people worldwide,” Dr. Perrier concluded.

Provided by
European Society for Organ Transplantation