On March 21st, a research team from Waterloo University in Ontario, Canada, announced the formulation of a new biomaterial that could be made into a contact lens to speed up the process of postoperative ocular wound healing. And that’s just one of many intriguing potential applications in the human body.
The biomaterial, called GelMA+, is a unique formulation of collagen-derivative gelatin methacrylate. GelMA+ would be used as the basis of a combination ophthalmic bandage lens and targeted-release drug delivery system.
“The technology is activated by enzymes released when the eye is in a wounded state,” said Dr. Lyndon Jones, a professor at Waterloo’s School of Optometry & Vision Science, director of the Centre for Ocular Research & Education (CORE) and lead author of the study.
“The amount of drugs released is tailored to the severity of the wound – with more drugs released when the wound is larger. This is important as it ensures an effective dose of drugs is released for healing while minimizing any potential for side effects.”
Dr. Jones’ team used bovine lactoferrin as an analog for a wound-healing drug and infused it into varying concentrations (20% and 30% weight per volume) of GelMA+. In a human cell culture study, the researchers achieved complete wound healing in five days using the new technology.1
The team believes that, once perfected, the biocompatible, collagen derivative can be used to fashion medicated bandage contact lenses that also drip-feed medicine to the ocular surface.
Currently, larger single doses of medication, like antibiotics, are administered alongside non-medicated bandage lenses. Much of this is drained or washed away by the eye’s defenses before ever reaching the wound. The extended-release system developed by the Waterloo team would maintain a steady, self-regulating concentration of medicine due to its novel mechanism of action.
According to Dr. Jones, the potential for GelMA+ goes beyond corneal injury. “This technology could extend beyond ophthalmology, with the potential for applications in other sites of the body as MMP enzymes are present whenever there is some type of wound. These other body sites could encompass things such as burns, bed sores, diabetic ulcers, venous (varicose veins) ulcers and many more. Not just eye related. Any site where MMPs are released.”
Breakthrough material
The team published their research findings in a December 2023 paper on MDPI.1 Developed by a cross-disciplinary team of vision care researchers and chemical engineers, GelMA+ is a strong, transparent, biocompatible film stable at room temperature, with a semi-porous surface that selectively traps molecules of medium-to-high molecular weight.
The substance also critically degrades in the presence of matrix metalloproteinase-9 (MMP-9), a tissue repair enzyme found throughout the body.
The degradation of the material in a wounded eye flush with MMP-9 is the source of the novel targeted-release mechanism. This all adds up to an organic contact lens that doubles as a chemical sponge which readily dissolves in the human eye.
Though GelMA hydrogels have been used for other biomedical applications, their use in the eye has proven difficult due to struggles in high wear-and-tear situations. The novel GelMA+ material showed an 8-fold increase in mechanical strength compared to previous GelMA formulations. The study authors attribute this crucial increase in durability to a longer incubation period, which gave rise to much improved crosslinking.1
The winding road ahead
Though his team has established proof of concept, Dr. Jones admits that much remains to be done before GelMA+ contact lenses become a reality. Having established the “what,” the team must now work out the “how” of turning GelMA+ into a working lens system.
“We have already conducted the basic characterization tests for tensile strength, wettability, and optical clarity and confirmed that the material is suitable for use as a lens material,” Dr. Jones said. “Of course, perfecting these parameters is something that could take a very long time depending on what is considered acceptable.”
The remaining hurdles are on the biomedical side. Dr. Jones acknowledges that “significant challenges remain in terms of integrating small molecular weight drugs with our material — a crucial area of ongoing research, given that many therapeutics are of small molecular size.
“Realistic timelines are always hard to give as the speed at which we can do research is dependent on funding availability, but optimistically, we would target two years to reach animal trials and an additional four years before we can begin clinical trials,” he concluded.
Reference
- Bose S, Phan CM, Rizwan M, Tse JW, Yim E, Jones L. Fabrication and Characterization of an Enzyme-Triggered, Therapeutic-Releasing Hydrogel Bandage Contact Lens Material. Pharmaceutics. 2023;16(1):26.
