Scientists have 3D printed corneas for the first time in new research, offering hope to millions of people around the world whose eyesight is affected by damage to the delicate tissue. The cornea is a clear sheath that sits over the iris and the pupil, helping to direct light rays onto the retina. If the cornea becomes damaged, the image sent to the brain can become blurry. Currently, patients with damaged corneas can undergo transplants in serious cases, but this necessitates a donor—of which there is a significant shortage.
Approximately 10 million people need surgery to prevent corneal blindness, while a further 5 million people are totally blind because the tissue is damaged or diseased.
Now, a team at Newcastle University in the U.K. believes it has paved the way for an unlimited supply of corneas, using a 3-D printer to create them in a lab.
The researchers took corneal stem cells from a healthy donor and mixed them together with alginate and collagen to create a printable “bio-ink.” This solution was then placed inside a simple 3-D printer.
The scientists were able to print a 3-D cornea in less than ten minutes. Building on previous work by the team showing stem cells can be kept alive for weeks at room temperature in a hydrogel similar to the bio-ink, the cells were shown to culture in the artificial cornea. As the corneas are easily printable, they can be created to match the size and shape of a patient’s eye.
“Theirs is the first to be printed with a curved shape, as previous versions featured layers of cells,” Che Connon, Professor of Tissue Engineering at Newcastle University and lead author of the study said. The resulting paper was published in the journal Experimental Eye Research.
“Many teams across the world have been chasing the ideal bio-ink to make this process feasible,” Professor Connon commented in a statement.
The gel, which is a combination of alginate and collagen—keeps the stem cells alive while producing a material which is stiff enough to hold its shape but soft enough to be squeezed out the nozzle of a 3-D printer.
“Now we have a ready-to-use bio-ink containing stem cells allowing users to start printing tissues without having to worry about growing the cells separately.”
Professor Connon said, “Despite the well-organized eyebank systems in developed nations, health care professional struggle to meet demand. That’s partly due to the increasing use of refractive [laser eye] surgery and eyes that have undergone refractive surgery currently cannot be used for transplantation. If we look more widely in less developed nations, eye-banking is poorly developed and an alternative that allows a rapid development of corneas, such as 3-D printing, would really be very useful.”
Professor Connon predicts the technology could be available in a minimum of five years, if clinical trials are a success.
“We are thinking ahead and imagining a situation where a doctor’s surgery has a 3-D printer in the corner, and a doctor can pull an ink from the shelf, plug it in and print.”