Imma Perfetto
Cosmos science journalist
An international team of scientists has 3D printed human islet – the insulin-producing cell clusters in the pancreas – in what they claim is “a critical step toward personalised, implantable therapies for diabetes.”
The durable, high density islet structures are designed to be implanted just under the skin. They have been shown to remain alive and functional, maintaining a strong insulin-producing response to glucose (sugar) for up to 3 weeks in laboratory experiments.
“This is one of the first studies to use real human islets instead of animal cells in bioprinting, and the results are incredibly promising,” says Dr Quentin Perrier of Wake Forest University’s Institute for Regenerative Medicine in the USA.
“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.”
Perrier led the research which is being presented at the European Society for Organ Transplantation (ESOT) Congress 2025 held from 29 June to 3 July in London.
Pancreatic islets secrete insulin to regulate blood sugar levels. But in people with Type 1 Diabetes (T1D), the immune system attacks and destroys them.
Islet transplantation has been used for decades as a treatment for the sickest T1D patients. It involves isolating islet cells from a donated pancreas and then infusing them into the patient’s liver. When successful, the islets start to release insulin within a couple of weeks.
But the isolation process damages the “extracellular matrix” (ECM) – the 3D structural framework of proteins and sugars that surrounds the islets.
The ECM is critical to islet function, so this is thought to contribute to the limited graft survival in islet transplantation.
“Our goal was to recreate the natural environment of the pancreas so that transplanted cells would survive and function better,” says Perrier.
“We used a special bioink that mimics the support structure of the pancreas, giving islets the oxygen and nutrients they need to thrive.”
The bioink is formulated from pancreas ECM and alginate, a carbohydrate found in brown algae that forms a viscous gum when hydrated with water.
Human islets were suspended in the bioink and gently printed out of an extrusion bioprinter using low pressure and slow speed (20 millimetres per minute).
The resulting porous structures were designed to enhance the flow of oxygen and nutrients to the islet cells and to promote the formation of blood vessels.
These factors are critical to the long-term survival and function of grafts after transplantation.
The researchers report that their approach reduced the physical stress on the islets and helped keep their natural shape, solving a major problem that had held back earlier bioprinting attempts.
The bioprinted islets remained alive and healthy with cell survival at more than 90%. After 3 weeks, they showed significantly higher insulin response to glucose levels compared to free islets.
The team says the technology could one day offer a safer and more comfortable alternative to traditional islet transplants for the treatment of T1D.
They are 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 to adapt the method to alternative sources of insulin-producing cells, including human stem cell-derived islets and islets from pigs, to overcome pancreas donor shortages.
“While there is still work to be done, this new bioprinting method marks a critical step toward personalised, implantable therapies for diabetes,” says Perrier.
“If clinical trials confirm its effectiveness, it could transform treatment and quality of life for millions of people worldwide.”