New diabetes treatment could eliminate need for insulin injections

Tested in mice, therapy involves a capsule of genetically engineered cells implanted under the skin that release insulin as required.

A cell-based diabetes treatment has been developed by scientists who say it could eliminate the need for those with the condition to inject insulin.

The therapy involves a capsule of genetically engineered cells implanted under the skin that automatically release insulin as required. Diabetic mice that were treated with the cells were found to have normal blood sugar levels for several weeks. Scientists said they hope to obtain a clinical trial licence to test the technology in patients within two years. If successful, the treatment would be relevant for all type 1 diabetes patients, as well as those cases of type 2 diabetes that require insulin injections.

Martin Fussenegger, who led the research at the ETH university in Basel, said: “By 2040, every tenth human on the planet will suffer from some kind of diabetes, that’s dramatic. We should be able to do a lot better than people measuring their glucose.” Fussenegger said that, if confirmed as safe and effective in humans, diabetes patients could be given an implant that would need to be replaced three times a year rather than injections, which do not perfectly control blood sugar levels, leading to long-term complications including eye, nerve and heart damage.

In Britain, about 400,000 people have type 1 diabetes and three million have type 2 diabetes, about 10% of whom need to inject insulin to control the condition.

Type 1 diabetes normally begins in childhood and is an autoimmune disease in which the body kills off all its pancreatic beta cells. The cells respond to the body’s fluctuating glucose levels by releasing insulin, which regulates blood sugar. Without beta cells, patients need to monitor glucose and inject insulin as required – typically several times each day. Previously, scientists have attempted to artificially cultivate pancreatic cells from patients’ stem cells. However, scientists have struggled to manufacture the cells at the scale necessary for clinical use, and the cells are naturally prone to dying off once introduced into the body, according to Fussenegger. “They are prima donnas in the cellular context,” he said.

His team took a different approach, choosing to re-engineer human kidney cells, known as HEK cells, to perform the function normally carried out by the pancreas. Two genes were introduced into the cells – one to make them sensitive to glucose levels and a second to instruct the cell to pump out insulin when glucose levels exceeded a threshold. “We believed we needed a more robust cell type if you go for cell-based therapies,” he said.

In the study, published in Science, the engineered HEK cells were found to outperform normal pancreatic cells in terms of their ability to regulate blood sugar in mice. They were healthy three weeks after the implant and performed normally on various tests designed to measure their ability to control blood sugar.

“It’s hard to understand why ours should be better than something that evolved for millions of years. It shows that as engineers, thinking rationally, we can also do a very good job.”

In the study, mice were treated such that they lost all their insulin-producing pancreatic cells. The cells were then implanted into the mice, enclosed in a teabag-like porous capsule that protected the human cells from the mouse immune system, but allowed insulin to diffuse out. In humans, the same approach would mean cells would not need to be genetically matched to the patient, and frozen capsules could be manufactured on an industrial scale.

The team behind the work have created a start-up to commercialise the technique and hope it could reach the market within a decade.
Emily Burns, research communications manager at Diabetes UK, said: “We can already replace the cells in the pancreas that are damaged in type 1 diabetes by using cells taken from donated pancreases, but one of the issues with this approach is that there aren’t enough donors. That’s why research like this is so important: finding ways to produce an unlimited supply of pancreatic cells, or cells that act like them, in the lab.”