Synthetic Fibers to Reverse Blindness

June 1, 2009 -- Synthetic fibers can now be embedded with three, and possibly more, drugs or proteins. The new fibers could be woven into a variety of materials that have unique and novel properties -- such as reversing blindness.

"The ultimate idea is to implant this material into the eye," said Bin Dong, a scientist from Drexel University who, along with Gary Wnek and Meghan Smith of Case Western University, detailed their work in the journal Small.

"One protein will eat the scar tissue away, and the other will help induce the differentiation of retinal progenitor cells," said Dong.

Previously scientists were only able to include one drug or protein inside an electrospun fiber because the two would often interact with each other in ways that would negate or modify their effects.

To get around this limitation, the Drexel and Case Western scientists put the drugs and proteins inside tiny capsules, which stop the molecules from interacting with each other until they break apart.For their first tests, the scientists incorporated both bovine albumin serum (BAS) and epidermal growth factor (EGF) into the same electrospun fiber. Each molecule was also linked to a particular fluorescent dye that appears under special light. Red for BAS, green for EGF.

A fleece or nylon that glows different colors at different times is the beginning, though. Restoring vision to the blind could be the first use for these drug- and protein-containing fabrics.

Working with Michael Young, an ophthalmologist at the Schepens Eye Research Institute, the Drexel and Case Western University researchers are trying to create a biodegradable synthetic fabric that could return sight to blind people.

Surgically implanted onto the retina during a 45-minute operation, the protein-equipped fabric would do two things. First, proteins in the fabric would eat away at the scar tissue created by diseases like retinitis pigmentosa and macular degeneration.Once that's done, other capsules would break apart and release a growth factor that would encourage cultured retinal progenitor cells on top of the fabric to create new, light-detecting cells. The nanofiber material would then provide a place for these new cells attach to and grow on. Once the cells were established -- between 24 and 48 hours -- the material would naturally degrade.

"We've been able to show that in mice we can restore some kind of meaningful vision," said Young. "Pigs have compatible cells, and the next step is to restore vision for them as well."

If the animal trials go well, Young estimates that it will be a minimum of three years before any human trials of the material can be attempted.

"It sounds very exciting that they were able to incorporate multiple proteins," said Paula Hammond of the Massachusetts Institute of Technology, who works with electrospun materials.

"This could be especially interesting for tissue regeneration and wound healing applications," said Hammond.