About 15 million people worldwide suffer from complications caused by either disease or trauma to the cornea, the outer surface of the eye. About a third of those people live with total blindness. With the availability of corneas for transplant far from meeting the demand, researchers have turned to various media for prosthetics. Recently, a team at Newcastle University discovered a way to recreate a human cornea, with living tissue, on a 3-D printer.
Most remarkably, the ink they developed contains living stem cells.
Printing Living Tissue
The researchers had to experiment with different types of collagen for the ink’s base, as well as the proportions of collagen and sodium alginate, an algae-based biomaterial used in the lab to grow cells. This combination of media and stem cells, called hydrogel, keeps the cells alive until they’re needed. After several attempts, the team was able to find a consistency that could both print and hold its structural integrity. In essence, they’re printing living tissue.
The living cells come from organ donors, and one cornea can be used to print several. This means a single donation can go much further than saving the sight of one recipient. The hydrogel also keeps the donated cells alive for days or even weeks without refrigeration, allowing researchers to use the ink as needed.
Regular 3-D Printer
The team uses an inexpensive 3-D printer, and each cornea takes about 10 minutes to print. This is a huge step up from previous attempts made using molds. Just as importantly, the printed corneas can be made to fit the exact dimensions of their recipients’ eyes.
While trials on humans are still years away, researchers are hopeful that 3-D printing will be the next innovation in human transplants.