Biomimetic materials pulsed with low-energy blue light can reshape damaged corneas

An injectable biomaterial activated by pulses of low-energy blue light has enormous potential for on-site repair of the domed outer layer of the eye, a team of researchers from the University of Ottawa and their collaborators has revealed. Credit: Faculty of Medicine, University of Ottawa

A new study reveals that biomimetic materials, when pulsed with low-energy blue light, can reshape damaged corneas, including increasing their thickness. The results have the potential to affect millions of people.

A team of researchers from the University of Ottawa and their collaborators have revealed the enormous potential of an injectable biomaterial that is triggered by low-energy pulses of blue light for immediate repair of the domed outer layer of the eye.

Following a design approach guided by biomimicry – innovation that takes inspiration from nature – the interdisciplinary researchers’ convincing results show that a new light-activated material can be used to effectively reshape and thicken damaged corneal tissue, promoting healing and restoration.

This technology is a potential game-changer in corneal repair; tens of millions of people worldwide suffer from corneal diseases, and only a small proportion are eligible for corneal transplantation. Transplant surgeries are the current gold standard for disorders that result in corneal thinning such as keratoconus, a poorly understood eye disease that results in vision loss for many people.

“Our technology is a leap in corneal repair. We are convinced that this can become a practical solution to treat patients living with diseases that negatively affect the shape and geometry of the cornea, including keratoconus,” says Dr. Emilio Alarcon, associate professor at the Faculty of Medicine in Ottawa and researcher at the BioEngineering and Therapeutic Solutions (BEaTS) group at the University of Ottawa Heart Institute.

The cornea is the protective, dome-like surface of the eye in front of the iris and pupil. It directs and directs light rays into the eye and helps achieve clear vision. It is usually transparent. But injury or infection results in scarring of the cornea.

Dr. Emilio Alarcon, associate professor at the University of Ottawa’s Faculty of Medicine and researcher at the BioEngineering and Therapeutic Solutions (BEaTS) group at the University of Ottawa Heart Institute. Credit: Faculty of Medicine, University of Ottawa

The collaborative team’s work was published in Advanced Functional Materials, a high-impact scientific journal.

The biomaterials devised and tested by the team consist of short peptides and naturally occurring polymers called glycosaminoglycans. In the form of a viscous liquid, the material is injected into corneal tissue after a small pocket is surgically created. When pulsed with low-energy blue light, the injected peptide-based hydrogel hardens and forms into a tissue-like 3D structure within minutes. Dr. Alarcon says this then becomes a transparent material with properties similar to those measured in porcine corneas.

In vivo experiments with a rat model indicated that the light-activated hydrogel could thicken corneas without side effects. The research team – which used a much smaller dose of blue light compared to what has been used in other studies – also successfully tested the technology in an ex vivo model of the porcine cornea. Trials in large animal models will be necessary prior to clinical trials in humans.

“Our material was engineered to harvest the blue light energy to trigger the assembly of the material in situ into a cornea-like structure. Our cumulative data indicate that the materials are non-toxic and persist for several weeks in an animal model. We expect , that our material will remain stable and non-toxic in human corneas,” says Dr. Alarcon, whose uOttawa lab focuses on developing new materials with regenerative capabilities for tissue in the heart, skin and cornea.

The rigorous research took over seven years to reach the publication stage.

“We had to engineer every part of the components involved in the technology, from the light source to the molecules used in the study. The technology has been developed to be clinically translatable, which means that all components must be designed to ultimately be able manufactured to strict standards of sterility,” says Dr. Alarcon.

The research results are also the focus of a patent application, which is currently under licensing negotiations.

Dr. Alarcon was the study’s senior author, guiding the materials design aspect of the research, while uOttawa’s Dr. Marcelo Muñoz and Aidan MacAdam played major roles in the creation of the new technology. Interdisciplinary collaborators included Université de Montréal researchers Dr. May Griffith, an expert in corneal regeneration, and Dr. Isabelle Brunette, an ophthalmology and cornea transplant expert.

Reference: “Low Energy Blue Pulsed Light-Activated Injectable Materials for Restoring Thinning Corneas” by Aidan J. MacAdam, Marcelo Munoz, Jinane El Hage, Kevin Hu, Alex Ross, Astha Chandra, Jodi D. Edwards, Zian Shahid, Sophia Mourcos, Maxime E. Comtois-Bona, Alejandro Juarez, Marc Groleau, Delali Shana Dégué, Mohamed Djallali, Marilyse Piché, Mathieu Thériault, Michel Grenier, May Griffith, Isabelle Brunette and Emilio I. Alarcon, 19 July 2023, Advanced functional materials.
DOI: 10.1002/adfm.202302721

The project was supported by a Collaborative Health Research Projects grant, an NSERC Discovery grant, the Government of Ontario, and the University of Ottawa Heart Institute.