Novel Bioadhesive Gel for Corneal Repair

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A team of researchers has described a simple treatment for the repair of corneal wounds that involves nothing more than a tube of adhesive and visible light.¹ In animal models, GelCore (for “gel for corneal regeneration”), a transparent bioadhesive gel that is still in development, sealed the eyeball and filled structural defects in the cornea for long periods of time without sutures, grafts, or bandage contact lenses.

“GelCore provides an alternative to current stan­dard treatment options,” said Nasim Annabi, PhD, at the University of California, Los Angeles. “It is designed to be applied easily, without the need for an operating theater, surgical skills, or even surgery rooms.” She singled out its potential on battlefields, where ocular injuries account for over 10% of injuries sustained by soldiers in combat.

Gelatin plus light. GelCore is a natu­rally derived biopolymer with charac­teristics similar to the native cornea. It is made from chemically modified porcine gelatin mixed with light-activated compounds. After applica­tion to the wound and brief exposure to a visible light cross-linking system, GelCore solidifies and firmly adheres to the corneal tissue, sealing the defect without sutures. To overcome biosafety concerns, the light intensity used in the cross-linking system is well below the maximum exposure limit, the research­ers said.

NO SUTURES. The biopolymer solution is injected into the corneal defect and exposed to visible light, forming the hydrogel.

Early results. Tests in rabbit eyes indicated that GelCore effectively sealed corneal defects and also promot­ed re-epithelization. In tests of wound closure strength, shear resistance, and burst pressure, GelCore performed sig­nificantly better than existing adhesives, which lack both high adhesion to wet corneal tissue and long-term retention.

“The glues in current use are asso­ciated with low biocompatibility, low adhesion, and poor transparency, and they are undesirably rough and difficult to handle,” said Dr. Annabi. “Our bio­material has shown prolonged reten­tion even when filling in large corneal tissue defects. And it could regenerate the damaged corneal tissue.”

Potential uses. GelCore is designed mainly for corneal deep scars, but the researchers are working on different formulations for uses ranging from large lacerations and corneal scars to infection and inflammation.

Dr. Annabi noted that its phys­ical and chemical properties can be fine-tuned for use not only in the cornea but also elsewhere in the body, including the lungs, skin, and heart. Moreover, she said, the gel can be used as a platform for delivering antimicro­bial agents or drugs to a targeted site to foster wound healing and prevent infection.

Years to market. Since testing in human patients has not yet begun, it could take five to six years to reach the market, Dr. Annabi said.

—Miriam Karmel

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1 Sani ES et al. Sci. Adv. Published online March 20, 2019.

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Relevant financial disclosures—Dr. Annabi: NIH: S; UCLA: S; U.S. Department of Defense: S.

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