Tokyo (SCCIJ) – Damage to the cornea, the tissue that protects your eye, affects millions of people worldwide. Now, researchers in Switzerland are developing a transparent, biocompatible implant using a 3D printer to repair defects seamlessly and permanently.
Biocompatible hydrogel
Like a windowpane, the transparent cornea is the outermost layer of tissue that protects our eyes. It is only 0.5 to 0.6 millimeters thick. If infections, injuries, or malformations damage it, vision impairment or even blindness can occur. But for every 70 people who need a corneal implant, only one donor implant is available. Only around 100,000 people each year receive it. Even when available, the quality varies based on the donor’s age and health. Corneal tissue also has a short shelf life, making storage and transport difficult.
A team of researchers from the Swiss Federal Laboratories for Materials Science and Technology (Empa), the University of Zurich, the Zurich Veterinary Hospital, and Radboud University in the Netherlands is now developing a self-adhesive implant that does not depend on tissue donations and does not trigger a rejection response. “The basis for the implant is a biocompatible hydrogel made of collagen and hyaluronic acid,” says Markus Rottmar from Empa’s Biointerfaces lab in St. Gallen. A generous donation from a foundation fully funded the project.
Artificial cornea supports healing
The transparent implant also contains additives to ensure optimum biomechanical stability. A 3D printer creates an individually adjusted artificial cornea. “3D extrusion bioprinting makes it possible to tailor the implant to the patient’s individual corneal curvature,” says Rottmar.
3D-printed corneas overcome the limitations of donated human tissue. Their quality would be consistent each time, eliminating the uncertainty tied to natural tissue. In October, a hospital in Haifa, Israel, successfully performed the first fully lab-grown corneal transplant. The recipient was a 70-year-old woman who had been blind in one eye. The Israeli company Precise Bio had created it with a 3D printer. This surgery marked a significant milestone for bioprinting because the artificial tissues function seamlessly within a living organ.
But the Swiss approach goes much further. Instead of stitching the artificial cornea on the surface of the eye, the researchers in Switzerland will load the hydrogel with human stem cells from the eye so that the artificial cornea can support tissue regeneration. And because the self-adhesive transplant does not require surgical sutures, it shortens operating times and avoids post-operative complications such as infection, scarring, or inflammation. Although these groundbreaking developments are still in early clinical stages, they mark the beginning of a transformative era in ophthalmology.
Text: Empa (Editing by SCCIJ)
