Scientists from Newcastle University (UK) have developed a “bio-ink” that allows them to successfully 3D print human corneas. The cornea is the outermost layer of the eye, and if it’s damaged by disease or injury a person can suffer vision problems, or even lose their sight. The only treatment for this is a cornea transplant, but there are not nearly enough donor corneas to meet the demand. This new discovery uses stem cells to create new corneas with 3D printing. The first step was to create a printable bio-ink that was able to hold the stem cells. This was a challenge because the material had to be “stiff enough to hold its shape yet soft enough to be squeezed out the nozzle of a 3D printer,” according to lead researcher Che Connon.

Once this problem was solved they were ready to test the process. They scanned the person’s eye to determine the cornea’s dimensions, ensuring that it would be a perfect match for the recipient’s eye size and shape. The 3D printer was used to construct a mould or ‘scaffolding’ in the shape of the cornea. The stem cells then grew around this scaffolding. It is the stem cells that actually become the cornea once they mature; the other parts of the bio-ink just support the stem cells. This research is still several years away from moving out of the lab and into the operating room, but if further testing yields positive results, then 3D-printed corneas have the potential to change millions of lives.