Human vision restored using corneal implants bioengineered from pig skin

For an estimated 12.7 million people worldwide who are blind due to corneal stromal disease, a cornea transplanted from a human donor is the only way to restore sight. However, he is only 1 in 70 patients who receive corneal transplants. Researchers now describe an acellular engineered corneal tissue implant made of collagen proteins from porcine skin and a minimally invasive surgical method for its implantation. In a pilot study conducted in India and Iran (clinicaltrials.gov no. NCT04653922), all 20 of her patients who received implants regained their vision.

This research nature biotechnologyin the article, “Bioengineered Corneal Tissue for Minimally Invasive Vision Restoration in Advanced Keratoconus in Two Clinical Cohorts.”

“The results show that we can develop a biomaterial that meets all the criteria to be used as a human implant. ,” said Neil Lagali. , PhD, Professor in the Department of Biomedical and Clinical Sciences, Linköping University (LiU), Sweden. “This avoids the shortage of donated corneal tissue and the problem of access to other treatments for eye disease.”

Twenty people who were blind or at risk of blindness (due to advanced keratoconus) entered a pilot clinical study and received biomaterial implants. The tissue healed rapidly. And eight weeks of treatment with immunosuppressive eye drops was sufficient to prevent implant rejection. No complications were observed.

The patient experienced an improvement in corneal thickness. Moreover, the curvature was restored normally. Participants’ vision improved as much as after corneal transplantation using donated tissue. Before surgery, 14 of the 20 participants were blind. Two years later, vision was restored in all 20 of her. Three of his Indian participants who were blind before the study regained full (20/20) vision after surgery.

The cornea is primarily composed of collagen molecules derived from pig skin, a by-product of the food industry, making it easily accessible and economically advantageous. In the process of constructing the implant, the researchers stabilized the loose collagen molecules to form a robust, transparent material that could withstand handling and implantation within the eye. Although it must be used, bioengineered corneas can be stored for up to two years before use.

Researchers have also developed a new minimally invasive method to treat keratoconus, a disease that causes the cornea to become so thin that it can lead to blindness. Currently, the corneas of patients with advanced-stage keratoconus are surgically removed, replaced with donated corneas, and sewn in place using surgical sutures. This type of surgery is invasive and is done only in large university hospitals.

“By using less invasive methods in more hospitals, we can help more people. Our method does not require the surgeon to remove the patient’s own tissue. A small incision is made into the existing cornea to insert the implant,” Lagali said.

This new surgical technique does not require sutures. Corneal incisions can be made with great precision thanks to advanced lasers, but can also be done manually using simple surgical instruments if desired. The method was first tested in pigs and found to be easier and potentially safer than conventional corneal transplants.

The use of implants in healthcare requires extensive clinical studies followed by market approval by regulatory authorities. The researchers also want to study whether the technology can be used to treat more eye diseases and whether implants can be personalized to make them even more effective.

“The safety and efficacy of bioengineered implants is at the heart of our research,” said Adjunct Associate Professor of Biomedical Engineering at LiU and of LinkoCare Life Sciences, which manufactures the bioengineered corneas used in the study. Founder and CEO Dr. Mehrdad Rafat said. “We have put a lot of effort into making our inventions widely available and affordable for everyone, not just the wealthy. can be used anywhere in the world.”