A research team in South Korea have used a 3D printer to improve the transparency of artificial corneas.
The team of researchers from Postech and Kyungpook National University School of Medicine printed an artificial cornea made from a bioink, consisting of decellularised corneal stroma and stem cells.
After comparing results of 3D printed and non-printed artificial corneal implants, they found higher transparency in their 3D-printed in vivo sample.
Postech Professor Jinah Jang said: “The strategy can achieve the criteria for both transparency and safety of engineered cornea stroma. We believe it will give hope to many patients [with] cornea related diseases.”
There are 2,000 patients in South Korea waiting for cornea donation, which takes six years on average.
The human cornea consists of a lattice pattern of collagen fibres, which is directly associated with its transparency. By regulating shear stress that occurred when ink passed through the printer nozzle, the research team were able to control the pattern of collagen fibre.
Corneal transplantation has so far been limited due to low transparency of replacements – this is essential, as the cornea is the outermost layer of the eye and therefore the first part to admit light.
Other artificial corneas have used recombinant collagen or chemical substances such as synthetic polymer, which does not incorporate well with the eye, nor is it transparent. This new version – described in Biofabrication – shows marked improvements in both respects and has the added advantage of being biocompatible.
This time last year, Newcastle University claimed the first 3D-printed human corneas. Scientists there combined stem cells from a healthy donor cornea with alginate and collagen to form a bioink, which was printed in concentric circles to replicate a real cornea. The stem cells were then shown to culture.
At the time, Professor Che Connon from Newcastle’s Institute of Genetic Medicine said: “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.”