Cyborg gel implant fights diabetes with light

Light can now be used to heal diabetes in mice. By implanting a transparent gel that contains genetically modified light-sensitive cells, researchers have demonstrated a new type of implant that could one day be used to treat disease and monitor toxins in people.

"Light is a great tool to interface with biological systems, but there is a fundamental problem. It gets scattered when it hits tissue, and at depths much thinner than our skin," says lead author Myunghwan Choi of Harvard Medical School in Boston.

Choi and his colleagues designed an implantable gel that could get around this, by guiding light under the mouse's skin. In experiments, the team impregnated the gel with different types of genetically modified cells before implanting it.

To control diabetes, the team shone light into the mouse and at the implanted gel using a fibre optic cable attached to its head. The light triggered cells in the gel to produce a compound that stimulated the secretion of insulin and stabilised blood glucose levels. Separately, the team also showed they could monitor for cadmium poisoning using cells that fluoresced when the mouse was under stress from the toxin.

Though still at the prototype stage, the ultimate idea is to reduce the need for doctors to perform repeated injections and blood tests to monitor or treat patients.