Ice cube tray retinal patch helps regenerate cells for vision
A novel type of scaffold shaped like an ice cube tray could help regenerate the eye’s photoreceptor cells, the death of which may cause vision loss in adults. The scaffold design by a team at the University of Wisconsin-Madison (UW-Madison) has significantly improved the precision with which replacement photoreceptor cells can be delivered into the eye and restore injured retinas.
Professor of ophthalmology and visual sciences David Gamm and the UW-Madison engineers have been investigating how synthetic patches can be used to hold photoreceptor cells and be implanted under a damaged retina to enable it to regenerate. A previous effort involved wine-glass-shaped pores to accommodate the photoreceptor cells, but proved to carry only a limited quantity of replacement cells.
The second-generation of their implantable scaffold, shaped like an ice cube tray, can hold three times as many photoreceptor cells – 300,000 of them in all – and features cylindrical holes on the underside so these cells can connect with the patient’s retinal tissue as they mature. It is made from a biocompatible material called poly(glycerol-sebacate) that offers the necessary mechanical strength, but is safely metabolised by the body after it serves its purpose.
“We wanted the material to be very strong, and in the eye, it degrades pretty quickly over about two months,” said graduate student Allison Ludwig, who works in Gamm’s lab. “That’s ideal for the human retina.”
The team plans to further refine the implantable scaffold by optimising its shape and fabrication technique; they say it is almost ready for testing in large animals, and hope to test it on humans in the future.
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