The material, called Duoptix, is made of two interwoven networks of hydrogels. One network, made of polyethylene glycol molecules, resists the accumulation of surface proteins and inflammation. The other network is made of molecules of polyacrylic acid, a relative of the superabsorbent material in diapers.
"Think of a fishnet, but think of a 3-D fishnet," says Curtis W. Frank, the W. M. Keck, Sr. Professor in Engineering and a professor, by courtesy, of chemistry and of materials science and engineering. "It's a strong, stretchy material." That makes it able to survive suturing during surgery. The biocompatible hydrogel is transparent and permeable to nutrients, including glucose, the cornea's favorite food.
David Myung, a medical student jointly working on a doctorate in chemical engineering in Frank´s laboratory also took part in the project. It was his part to design, fabricate and characterize a bioengineered cornea based on the dual-network hydrogel. The result was a disc with a clear centre and tiny pores populating the periphery. Myung calls the pores engineered into his artificial cornea the "homes" he built for cells that need to infiltrate the artificial lens and integrate it with surrounding natural tissue.
"If you build it, they will come," Myung says. "The cells move in, and they bring furniture too--meaning the collagen they secrete. They even 'remodel.'" Collagen binds to the edge of the synthetic disc and forms a junction between natural and synthetic tissues. Then a clear layer of epithelial cells grow over the disc.
If eyes are "the windows of the soul," corneas are the panes in those windows. They shield the eye from dust and germs. They also act as the eye's outermost lens, contributing up to 75 percent of the eye's focusing power.
MEDICA.de; Source: Stanford University