Researchers at Virginia Commonwealth University and Johns Hopkins University used a nanoparticle-encapsulated eye medication to decrease the risk of corneal graft rejection in animal models.
Each year, approximately 80,000 corneal transplantations take place in the U.S. However, rejection rates for the corneal grafts can be as high as 10%. This is largely due to poor patient compliance to the medications, which require frequent administrations of topical eyedrops over a long period of time.
The tedious process of eyedrop dosing causes a tremendous burden for patients. The resulting noncompliance to medication treatment can lead to even higher graft-rejection rates.
Each nanoparticle encapsulates a drug called dexamethasone sodium phosphate, one of the most commonly used corticosteroids for various ocular diseases treatment such as ocular inflammation, noninfectious uveitis, macular edema and corneal neovascularization. By using the nanoparticles to control the release of the medicine over time, patients would require only one injection right after the corneal transplantation surgery without the frequent eye drops. The research team’s studies have shown that when using this method the medication maintains its efficacy for six months on a corneal graft rejection model.
“To improve patient compliance and treatment efficacy, we developed a tiny nanoparticle (around 200 nanometers) that in animal studies enables the release of the drug up to six months after a single subconjunctival injection along the eyeball," said Qingguo Xu, D.Phil., the principal investigator of this project and an associate professor of pharmaceutics and ophthalmology at VCU School of Pharmacy.
The nanoparticle approach reversed signs of early rejection and maintained corneal grafts for six months without rejection.