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. On Sept. 11 in San Francisco at the annual meeting of the American Chemical Society, chemical engineer Curtis W. Frank will present a novel biomimetic material that's finding its way into artificial corneas. It's a hydrogel, or polymer that holds a lot of water. That material may promise a new view for at least 10 million people worldwide who are blind due to damaged or diseased corneas or many millions more who are nearsighted or farsighted due to misshapen corneas.
Called DuoptixTM, the material can swell to a water content of 80 percent--about the same as biological tissues. It's 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 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.
Collaborators on the hydrogel work that Frank is presenting at the chemists' meeting are Marianne E. Harmon, a former Stanford doctoral student now with GE Corporate Research Lab in Schenectady, N.Y.; Dirk Kucklung, an assistant professor at the Institute for Polymer Science in Dresden, Germany; Wolfgang Knoll, director of the Max Planck Institute for Polymer Research in Mainz, Germany; and David Myung, a medical student jointly working on a doctorate in
Contact: Dawn Levy