Next-Generation Tools to Treat Abnormal New Ocular Blood Vessels Yannis M. Paulus, M.D., has been awarded two grants to advance two novel technologies, each with the potential to revolutionize the treatment of a range of vision-threatening conditions. A Nanoneedle Array for Long-Term, Sustained Intraocular Drug Delivery National Institutes of Health/
National Eye Institute Research Project Grant (NEI R01) Photo-Mediated Ultrasound Therapy to Remove
The development of new blood vessels, or neovascularization,
Microscopic Blood Vessels Alcon Research Institute
is a major cause of blindness worldwide. It occurs in conditions
Young Investigator Grant
ranging from diabetes and macular degeneration to corneal diseases. Current treatments are suboptimal in that they can
Choroidal neovascularization, the development of new blood
involve frequent, often monthly, injections inside the eye, which
vessels in the choroid, is the leading cause of vision loss due
carry risks of infection, among other effects.
to wet age-related macular degeneration (AMD).
Recent attempts to design systems to deliver drugs through the corneal barrier, notably biodegradable ‘microneedles’, have proven problematic.
(anti-VEGF therapy) and laser photocoagulation. Both have
Dr. Paulus is collaborating with Dr. Chi Hwan Lee in the
considerable shortcomings.
Weldon School of Biomedical Engineering at Purdue University
Anti-VEGF therapy can result in serious complications like
to develop a novel platform technology that delivers long-term,
infection, bleeding, glaucoma, and cataracts. Moreover, despite
sustained intraocular drugs through fully-miniaturized, slowly-
repeated treatments, some patients end up with significant vision
biodegradable silicon ‘nanoneedles’ embedded on a water-
loss or blindness.
soluble contact lens. “Nanotechnology makes so many improvements possible,”
The current method of photocoagulation delivers a high dose of short duration laser energy. At that intensity, it can
explains Dr. Paulus. “Our nanoneedles are more than 30 times
damage surrounding healthy cells, leading to serious side effects
smaller than microneedles, and they degrade more than ten
like retinal atrophy and loss of peripheral and night vision.
times more slowly, providing longer-lasting therapy. And the
Dr. Paulus is part of a multidisciplinary team of researchers,
best part is that this is as simple as putting in a contact lens.
including Drs. Xueding Wang and Xinmai Yang, that developed
The contact lens dissolves within 30 seconds, leaving nanonee-
and patented a novel non-invasive alternative — photo-mediated
dles embedded in the peripheral cornea for long-term, sustained
ultrasound therapy, or PUT.
drug delivery.” The R01 grant (overseen by NEI Bioengineering and
“PUT delivers synchronized nanosecond laser pulses and ultrasound bursts at unprecedented speed and significantly lower
Technology Program Director Tony Gover, Ph.D.) will be used
laser intensity,” explains Dr. Paulus. “That combination allows
to evaluate nanoneedle platforms of different sizes, shapes,
us to target micro vessels with a degree of precision not achieved
aspect ratios and porosities, and to compare the safety, efficacy,
with conventional photocoagulation, and with far less risk of
and side effects of silicon nanoneedles to the current anti-
damage to surrounding tissues.”
vascular endothelial growth factor and laser therapies. “Our goal is a minimally-invasive platform for painless, sustained intraocular drug delivery,” Dr. Paulus says. “This idea has broad applications beyond corneal neovascularization,
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Two main treatments are currently used: frequent (often monthly) injections of anti-vascular endothelial growth factor
He will use the Alcon grant for studies comparing the effectiveness of PUT and anti-VEGF therapy — a vital next step in moving PUT closer to clinical application. “PUT also has the potential to transform how we care for
including the treatment of diabetic retinopathy, macular
patients with other neovascular, oncologic, and dermatologic
degeneration, infections, dry eyes, and glaucoma.”
conditions.”
