iNDICA NEWS BUREAU-
Researchers and entrepreneurs in Sweden have developed an implant made of collagen protein from pig’s skin resembling human cornea and, in a pilot study, the implant restored vision to 20 people with diseased corneas, most of whom were blind prior to receiving the implant.
The study, jointly led by researchers at Linkoping University (LiU) and LinkoCare Life Sciences AB in Sweden, has been published in Nature Biotechnology.
The promising results, experts say, bring hope to those suffering from corneal blindness and low vision by providing a bioengineered implant as an alternative to the transplantation of donated human corneas, which are scarce in countries where the need for them is greatest.
“The results show that it is possible to develop a biomaterial that meets all the criteria for being used as human implants, which can be mass-produced and stored for up to two years and thereby reach even more people with vision problems,” said Neil Lagali, professor at the Department of Biomedical and Clinical Sciences at LiU, one of the researchers behind the study. “This gets us around the problem of shortage of donated corneal tissue and access to other treatments for eye diseases.”
According to the university, an estimated 12.7 million people around the world suffer from corneal blindness. The cornea is the transparent part of the eye that covers the iris and the pupil and allows light to enter.
Their only way of regaining vision is to receive a transplanted cornea from a human donor. But just one in 70 patients receives a cornea transplant. Furthermore, most of those who need cornea transplants live in low and middle-income countries in which access to treatments is very limited.
“Safety and effectiveness of the bioengineered implants have been the core of our work, says Mehrdad Rafat, the researcher and entrepreneur behind the design and development of the implants. He is an adjunct associate professor (senior lecturer) at LiU’s Department of Biomedical Engineering and founder and CEO of the company LinkoCare Life Sciences AB, which manufactures the bioengineered corneas used in the study.
“We’ve made significant efforts to ensure that our invention will be widely available and affordable by all and not just by the wealthy. That’s why this technology can be used in all parts of the world,” Rafat said.
The cornea consists mainly of protein collagen. To create an alternative to the human cornea, the researchers used collagen molecules derived from pig skin that were highly purified and produced under strict conditions for human use. The pig skin used is a by-product of the food industry, making it easy to access and economically advantageous.
In the process of constructing the implant, the researchers stabilized the loose collagen molecules forming a robust and transparent material that could withstand handling and implantation in the eye. While donated corneas must be used within two weeks, the bioengineered corneas can be stored for up to two years before use.
The researchers have also developed a new, minimally invasive method for treating the disease keratoconus, in which the cornea becomes so thin that it can lead to blindness.
Today, a keratoconus patient’s cornea at an advanced stage is surgically removed and replaced by a donated cornea, which is sewn into place using surgical sutures. This kind of surgery is invasive and only done at larger university hospitals.
“A less invasive method could be used in more hospitals, thereby helping more people. With our method, the surgeon doesn’t need to remove the patient’s own tissue. Instead, a small incision is made, through which the implant is inserted into the existing cornea,” said Neil Lagali, who led the research group that has developed this surgical method.
No stitches are needed with this new surgical method. The incision in the cornea can be made with high precision thanks to an advanced laser, but also when needed, by hand with simple surgical instruments. The method was first tested on pigs and turned out to be simpler and potentially safer than a conventional cornea transplant.
The surgical method and the implants were used by surgeons in Iran and India, two countries where many people suffer from corneal blindness and low vision, but where there is a significant lack of donated corneas and treatment options.
Science frontiers: Bioengineered cornea may help the blind regain sight
