Summary: Researchers have developed a cornea implant from the collagen protein of pig skin. The implant restored the vision of 20 people with diseased corneas. The new implant could be a viable alternative to human cornea transplantation.

Source: Linkoping University

Researchers and entrepreneurs have developed an implant made of collagen protein from pig’s skin, which resembles the human cornea. 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 Linköping University (LiU) and LinkoCare Life Sciences AB has been published in Nature Biotechnology.

The promising results 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 up to two years and thereby reach even more people with vision problems. This gets us around the problem of shortage of donated corneal tissue and access to other treatments for eye diseases”, says Neil Lagali, professor at the Department of Biomedical and Clinical Sciences at LiU, one of the researchers behind the study.

An estimated 12.7 million people around the world are blind due to their corneas, which is the outermost transparent layer of the eye, being damaged or diseased. 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”, he says.

The cornea consists mainly of the protein collagen. To create an alternative to 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 byproduct 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 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”, says Neil Lagali, who has 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. Twenty people who were either blind or on the verge of losing sight due to advanced keratoconus participated in the pilot clinical study and received the biomaterial implant.

Bioengineered Cornea Can Restore Sight to the Blind and Visually Impaired

Cornea implant made of collagen protein from pig’s skin. Credit: Thor Balkhed/Linköping University

The operations were free from complications; the tissue healed fast; and an eight-week treatment with immunosuppressive eye drops was enough to prevent rejection of the implant. With conventional cornea transplants, medicine must be taken for several years. The patients were followed for two years, and no complications were noted during that time. 

The primary purpose of the pilot clinical study was to investigate whether the implant was safe to use. However, the researchers were surprised by what happened with the implant. The cornea’s thickness and curvature were restored to normal. At the group level, the participants’ sight improved as much as it would have after a cornea transplant with donated tissue.

Before the operation, 14 of the 20 participants were blind. After two years, none of them was blind any more. Three of the Indian participants who had been blind prior to the study had perfect (20/20) vision after the operation. 

A larger clinical study followed by market approval by regulatory authorities is needed before the implant can be used in healthcare. The researchers also want to study whether the technology can be used to treat more eye diseases, and whether the implant can be adapted to the individual for even greater efficacy.

LinkoCare Life Sciences AB, which is responsible for the production, certification, packaging, and sterilisation of the implants used in the study, with the support of Care Group India, covered the cost of implant manufacturing, ISO-compliant preclinical testing, and clinical testing.

Further funding for the study for biomaterials and surgical development and testing came from the European Union Horizon 2020 Programme, and ALF funds from Linköping University and the Östergötland Region. These funders did not participate in the design or execution of the research. Mehrdad Rafat is the patent holder, via LinkoCare AB, and sits on the company’s board. Another of the study’s co-authors (Shideh Tabe) also sits on the company’s board. 

About this visual neuroscience and neurotech research news

Author: Anders TörneholmSource: Linkoping UniversityContact: Anders Törneholm – Linkoping University
Image: The image is credited to Thor Balkhed/Linköping University

Original Research: Open access.
“Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts” by Mehrdad Rafat et al. Nature Biotechnology


Abstract

Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts

Visual impairment from corneal stromal disease affects millions worldwide. We describe a cell-free engineered corneal tissue, bioengineered porcine construct, double crosslinked (BPCDX) and a minimally invasive surgical method for its implantation. In a pilot feasibility study in India and Iran (clinicaltrials.gov no. NCT04653922), we implanted BPCDX in 20 advanced keratoconus subjects to reshape the native corneal stroma without removing existing tissue or using sutures.

During 24 months of follow-up, no adverse event was observed. We document improvements in corneal thickness (mean increase of 209 ± 18 µm in India, 285 ± 99 µm in Iran), maximum keratometry (mean decrease of 13.9 ± 7.9 D in India and 11.2 ± 8.9 D in Iran) and visual acuity (to a mean contact-lens-corrected acuity of 20/26 in India and spectacle-corrected acuity of 20/58 in Iran).

Fourteen of 14 initially blind subjects had a final mean best-corrected vision (spectacle or contact lens) of 20/36 and restored tolerance to contact lens wear.

This work demonstrates restoration of vision using an approach that is potentially equally effective, safer, simpler and more broadly available than donor cornea transplantation.

TECH NEWS RELATED

New cleaning technique boosts electronic and photonic prospects of aluminum nitride

Cross-sectional microscopy images of molecular beam epitaxy-grown aluminum nitride on aluminum nitride templates. The black squares in (A) and (E) mark the regions where the corresponding magnified images (B to D and F to H) are taken. The white notches in (A) and (E) indicate the growth interfaces. The ...

View more: New cleaning technique boosts electronic and photonic prospects of aluminum nitride

Utilizing chemo-mechanical oscillations to mimic protocell behavior in manufactured microcapsules

Credit: Oleg E. Shklyaev et al, Matter (2022). DOI: 10.1016/j.matt.2022.06.063 The complexity of life on Earth was derived from simplicity: From the first protocells to the growth of any organism, individual cells aggregate into basic clumps and then form more complex structures. The earliest cells lacked complicated biochemical machinery; ...

View more: Utilizing chemo-mechanical oscillations to mimic protocell behavior in manufactured microcapsules

Research team develops a cleaner, more cost-effective way to make useful industrial chemicals

Credit: Tony Jin et al, Angewandte Chemie International Edition (2022). DOI: 10.1002/anie.202207206 Two renewable resources—cellulose from wood pulp and chitin from the shells of crabs, lobsters and other crustaceans—are known to industrial chemists for their potential for creating highly versatile nanocrystals, useful for making pharmaceuticals, cosmetics, industrial additives and ...

View more: Research team develops a cleaner, more cost-effective way to make useful industrial chemicals

Climate change made summer drought 20 times more likely

Credit: Pixabay/CC0 Public Domain Drought that stretched across three continents this summer—drying out large parts of Europe, the United States and China—was made 20 times more likely by climate change, according to a new study. Drought dried up major rivers, destroyed crops, sparked wildfire, threatened aquatic species and led ...

View more: Climate change made summer drought 20 times more likely

Study: Removing GRE requirement does not undermine student success

Credit: Unsplash/CC0 Public Domain In 2019, Boston University School of Public Health (BUSPH) eliminated the Graduate Record Examination as a requirement for admission to the school’s graduate programs for a pilot period of three years. The school’s decision was fueled by a growing body of data that indicated that ...

View more: Study: Removing GRE requirement does not undermine student success

Earth System Grid Federation launches effort to upgrade climate projection data system

A simulation of the planet from the DOE Energy Exascale Earth System Model, one of the large-scale models incorporated in the Earth System Grid Federation led by DOE’s Oak Ridge, Argonne and Lawrence Livermore national laboratories. Credit: LLNL, U.S. Dept. of Energy The Earth System Grid Federation, a multi-agency ...

View more: Earth System Grid Federation launches effort to upgrade climate projection data system

Some everyday materials have memories, and now they can be erased

In this study, the research team tracked the locations of 25,000 tiny particles that make up a two-dimensional disordered solid. Groups of particles rearrange as the solid is deformed. This diagram depicts when particles are rearranged as the material is deformed in one direction (left) or the opposite direction ...

View more: Some everyday materials have memories, and now they can be erased

Shocking Study Finds Decreased Proteins – Not Amyloid Plaques – Cause Alzheimer’s Disease

The prevailing theory is that Alzheimer’s disease is caused by the buildup of amyloid plaques in the brain. However, new research finds that it is actually caused by a decline in levels of a specific protein. New research on patients with mutations published in the Journal of Alzheimer’s Disease. ...

View more: Shocking Study Finds Decreased Proteins – Not Amyloid Plaques – Cause Alzheimer’s Disease

Logging down the value chain raises future forest sustainability concerns

SpaceX capsule heads to space station ferrying NASA crew and Russian

Documentary featuring Professor Sara Seager wins Emmy Award

Petting Dogs Engages the Social Brain, According to Neuroimaging

Do You Act Before You Think or Think Before You Act?

A Possible Brain Mechanisms Behind COVID-19 Delirium

Researchers develop new tool for targeted cell control

Researchers pioneer nanoprinting electrodes for customized treatments of neurological disorders

Study shows challenge of promoting citizen science to help prevent disasters caused by flooding

Crew Dragon launches safely, carrying first Russian from US soil in 20 years

Click! 2022 Nobel goes to chemistry made simple and reliable

A Nose to Diagnose: Improving Parkinson’s Diagnosis

OTHER TECH NEWS

Top Car News Car News