3D Printed Microneedle Array Technology May Offer New Eye Disease Treatment

According to a report commissioned by the Prevent Blindness America organization, eye disorders and treatment for people with vision loss cost close to $139 billion annually. 3D printing has been called on multiple times to help learn about and diagnose eye disease, as well as to create implants and create corneas for transplant patients, but it’s not used as often to treat them, as it can be very difficult to deliver drugs into a person’s delicate eyes. But a researcher from Washington State University (WSU) has just been awarded a grant from the US Department of Defense to come up with an easier, less expensive and painful way to treat serious eye diseases…using 3D printing.

While eye drops may seem convenient, they’re not always that effective because they can be diluted by tears. A physical barrier exists between most parts of a person’s eye and its blood vessels, so doctors often have to turn to direct eye injections and laser surgery to treat eye disease. Unfortunately, periodic direct eye injections can each cost nearly $2,000, and laser therapy comes with some risky side effects. That’s why it’s so important to use modern technology to find less costly and more efficient ways to deliver ocular drugs.

WSU Assistant Professor Kuen-Ren “Roland” Chen

The DoD gave Kuen-Ren “Roland” Chen, an assistant professor in the WSU School of Mechanical and Materials Engineering, an 18-month, $264K exploratory grant to develop a programmable microneedle array, using 3D printing, that will be able to deliver drugs in a sustained manner directly into a patient’s eye.

Touted as a minimally invasive, pain-free alternative to the standard, scary-looking hypodermic needle and syringe, microneedles are tiny, and can be stacked next to each other in a group to form a microneedle array. Chen, along with WSU PhD student Maher Amer, is working to improve upon existing microneedle technology by developing a locking and unlocking technique for an array of 3D printed microneedles.

Chen’s method locks microneedles in place with a polymer gel, and would give doctors a way to attach the array to a patient’s eye, so necessary drugs can be delivered for long periods of time; later, the microneedle array can be easily detached.

Mock-up prototype of the microneedle array. Item is not made of the final material with the programmable feature. It shows the relational size of the microneedles and the actual device. The ultimate overall diameter will be smaller than what’s shown in the photo.

Not only does a steady, sustained delivery of drugs make delivery more efficient, it also lowers the cost by reducing how much of the drug is required for treatment, as well as limit visits to the patient’s clinic or hospital. In addition, Chen said that his 3D printed microneedle array technology will cause fewer side effects and less pain than direct eye injections, and also be far less invasive.

Right now, the researchers are in the middle of developing the necessary mold for fabricating the microneedles, and testing out Chen’s innovative locking mechanism. Chen and Amer have initial plans to develop the microneedle array so that it can deliver drugs directly into the eye for a month. While this sounds like a terrifyingly long amount of time, it could actually lower abnormal blood vessel growth more effectively than using a single direct eye injection.

In the future, the technology could potentially be used to treat major eye diseases, like age-related macular degeneration and diabetic retinopathy.

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