The group, from Cornell University in the US, were inspired by a spider’s web covered in droplets of dew as they considered new ways to tackle type one diabetes.
For patients with the disease, immune systems destroy insulin-producing pancreatic cell clusters called islets, resulting in high blood sugar levels and symptoms including frequent urination, weight loss and increased hunger. To cope with symptoms and prevent serious complications – and potential death – patients take daily insulin injections or have stem cell-derived islet transplants.
However, transplants require long-term drug treatment and can cause tumours if left in the body. “When they fail or die, they need to come out,” said biological and environmental engineer Minglin Ma. “You don’t want to put something in the body that you can’t take out. With our method, that’s not a problem.”
To tackle the issue, the team coated a polymer thread with a thin hydrogel coating containing hundreds of thousands of islets, similar to web covered in dew. The threads could be implanted in minimally-invasive keyhole surgery, the team said, with a 6ft length in the abdomen potentially providing treatment for six months to two years before being removed.
“It’s minimally reactive, it protects the islet cells… and it can be easily removed,” said James Flanders from Cornell, who tested short threads in mice and dogs. “To me, it sounded like a win-win.”
Although stem cell-derived treatments already exist, the researchers’ “innovative” web-inspired approach could let doctors easily control and remove the cells when needed to prevent tumours and growths, said Helen Meese, member of the IMechE’s biomedical engineering division, to Professional Engineering.
“In terms of actually finding a solution to the problem, it is a really good use of technology and a very simple way of being able to create the cell therapy,” she said.
New hydrogel materials, coatings or nano-technologies could lead to longer-lasting threads in future, she added. However, she said, there may be a while to wait before they are in use. “They will have to do an awful lot of testing… before we see it as a marketable device,” she said.
Danish pharmaceutical giant Novo Nordisk, which developed injectable insulin more than 90 years ago, gave patent protection to the string, known as Thread-Reinforced Alginate Fibre for Islets Encapsulation (Traffic).
The research was published in the Proceedings of the National Academy of Sciences.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.