Shark cage implant protects insulin-producing cells in diabetic mice

A few years ago, researchers at Washington University in St. Louis developed a way to replenish beta cells in diabetic mice. First they converted skin cells taken from the animals into induced pluripotent stem cells (iPS cells), which can differentiate into a range of other cell types – in this case, beta cells. These were then implanted into the mice, allowing them to once again regulate their insulin levels and functionally curing their diabetes.

But of course, there’s a big caveat there – giving them more beta cells isn’t going to help for long when their immune systems are just going to attack the new ones too. In the previous study, the researchers had to suppress the animals’ immune systems, which is too dangerous a step for human use.

So for the new study, the team collaborated with scientists at Cornell University to develop a device that protects the implanted beta cells, while still allowing them to perform their vital function. These cells are housed inside a tiny device that protects them from the animal’s immune system, like a shark cage.

The device is made up of a hydrogel core that contains the beta cells, wrapped in a porous skin of nanofibers. The concept sounds deceptively simple – the pores are large enough for the insulin to escape, but too small for immune cells to enter. This was then implanted into the abdomens of the test mice. The cells in the implants remained functional for up to 200 days, keeping the animals’ diabetes in check for that whole time while leaving their immune systems operating just fine.