New uses for polymers aim to improve patients' lives
Dispersed in the vitreous humor after injection, drugs encapsulated in multi-layered polymer capsules could soon deliver an entire year’s worth of medication in a single injection. These devices could lower costs, cause less pain, and reduce the risk of intraocular side effects without interfering with vision.
As a PhD candidate, Katelyn Swindle-Reilly worked on injectable vitreous substitutes made from polymers. She moved on to research polymers for nerve regeneration and wound healing, but when she came to Ohio State and realized there were strong collaborations available in ophthalmology, optometry and biomedical engineering, she decided to return to her early research on polymers for use in the eye
“We generally do polymeric materials for implants or devices, but then I had the opportunity to use some of the knowledge I’d picked up from working in drug delivery through wound care products,” said Swindle-Reilly, who is an assistant professor of chemical and biomolecular engineering, ophthalmology, and biomedical engineering. “I always knew that I wanted a career that contributed to society. I thought I could make a difference if I was doing biomedical research that could help people live better quality lives."
Dr. Matthew Ohr approached Swindle-Reilly about working together to develop a drug delivery device to extend the durability of monthly anti-VEGF injections patients receive for wet AMD. After collaborating with this idea, they received two years of funding from the Ohio Lions Eye Research Foundation, which has catapulted their project.
“Right now, in the clinic, they’re injecting it in aqueous solution. It loses activity and diffuses out of the eye,” said Swindle-Reilly. “We’re encapsulating it in small, multi-layered particles; that way it slows release so a patient can have an injection once or twice a year, in theory.”
Ohr and Swindle-Reilly are currently working on creating the devices, cytotoxicity testing and making sure release-rates are controlled properly.
“We hope to move into further pre-clinical studies in the near future. So, we’ll be looking for funding from other sources in order to keep the project moving forward,” said Swindle-Reilly.
Other projects in the works are connected by their use of polymers to treat diseases in the eye. They’re looking at improving corneal wound healing outcomes to prevent scarring, topical drug delivery systems, and improving outcomes for post-cataract surgery patients by redesigning intraocular lenses to prevent cells from migrating onto the surface and causing secondary cataract.
The team is also working to develop next-generation vitreous substitutes that better match the optical and mechanical properties of the natural vitreous. The silicone oil typically used has none of the properties of the native tissue, which can cause complications.
“We’re interested in designing a synthetic polymer, that way it would be permanent,” said Swindle-Reilly. “With the silicone oil you can’t leave it in the eye forever and you don’t want to.”
They are also working on locally-delivered treatments for traumatic optic neuropathy, an injury often seen by military personnel and car crash victims.
“We’ll have a gel loaded with some neuro-protective agent and we’ll deliver it behind the eye,” she said. That project is a collaboration with Ohio State Drs. Matthew Reilly, Colleen Cebulla and Mohamed Abdel-Rahman.