An article published in the scientific journal Nature Biotechnology August 11, 2022 shows promising results for people with blindness due to corneal deformity. A team of researchers from the University of Linköping (Sweden) has designed a bioartificial cornea from collagen proteins from pig skin. As part of this pilot clinical study, 20 Indian and Iranian patients with advanced keratoconus, a disease that alters the shape of the cornea and leads to degradation of vision, benefited from a transplant. After two years of follow-up, all have at least partially recovered their sight and three of the 14 blind patients have even recovered perfect vision.
This bioartificial cornea is inserted into the recipient’s cornea through a small incision. “It is not necessary to remove the existing cornea, a pocket is created there where the porcine collagen is inserted”explains Professor Éric Gabison, ophthalmic surgeon. “This study confirms the stability of xenografts, that is to say grafts that do not contain human cells, since the implants hold together well. » Indeed, no observed patient suffered from graft rejection. Their cornea thickened, promoting a restoration of sight. In addition, these grafts can be stored for up to two years before implantation, compared to only two weeks for human corneas from deceased donors.
New perspectives
In a press release, the research team indicates that these new implants constitute “an alternative to transplanting donated human corneas, which are in short supply in the countries that need them the most”. They might be produced in abundant quantities and stored. She recalls that 12.7 million people in the world are blind due to corneal disease, but that only one in 70 patients benefits from a human corneal transplant.
“Nothing replaces a human corneal transplant, which offers the best results, but this type of implant opens up many perspectives for treating eye diseases”, says Professor Gabison. In October 2021, for the first time in Europe, he performed a 100% artificial corneal transplant on a patient who then regained her sight. However, he recalls that bioartificial transplants are not suitable for patients suffering from corneal opacity, who represent more than 90% of transplant applicants in France.
The interest of the porcine model
The use of pig collagen also confirms the interest of this species for human health research, a few months following the first successful transplant of a pig heart on a patient. “The pig is increasingly used as a biomedical model, due to immunological and biological links with the human species”, explains François Meurens, professor of immunology and specialist in the porcine model.
“Studies are being carried out on pig skin, its tissues, its heart, its respiratory system, its digestive system, but also at the brain level. It is therefore not surprising that this bioartificial cornea is designed from pig cells. On the other hand, we must salute the technological prowess. » A larger clinical study and marketing authorization are now necessary for the large-scale use of the implant in the field of health.