Scientists at Newcastle University in the UK have been the first to 3D-print human corneas, using a technique that could ensure an unlimited supply of corneas in the future.
There is a significant shortage of corneas available for transplants, while around 10 million people worldwide require surgery to prevent corneal blindness as a result of diseases such as trachoma. Almost five million people suffer total blindness from corneal scarring caused by burns, lacerations, abrasion or disease.
The proof-of-concept research for the new 3D-printing technique, published in Experimental Eye Research, reports how human corneal stromal cells were taken from a healthy donor cornea and mixed together with alginate and collagen to create a ‘bio-ink’ solution that could be printed.
Using a low-cost 3D bio-printer, the bio-ink was successfully printed in concentric circles to form the shape of a human cornea in less than 10 minutes. The stem cells were then shown to culture.
Newcastle University professor of tissue engineering Che Connon led the work. He said: “Many teams across the world have been chasing the ideal bio-ink to make this process feasible.
“Our unique gel, a combination of alginate and collagen, keeps the stem cells alive whilst producing a material which is stiff enough to hold its shape but soft enough to be squeezed out the nozzle of a 3D printer.
“This builds upon our previous work in which we kept cells alive for weeks at room temperature within a similar hydrogel. 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.”
The scientists also demonstrated that they could build a cornea to match unique patient specifications.
The dimensions of the printed tissue were originally taken by scanning a patient’s eye and using the data to rapidly print a cornea which matched the size and shape.
Connon added: “Our 3D-printed corneas will now have to undergo further testing and it will be several years before we could be in the position where we are using them for transplants.
“However, what we have shown is that it is feasible to print corneas using coordinates taken from a patient eye and that this approach has potential to combat the worldwide shortage.”