Two research institutions are actively developing artificial corneas made of high-water-content plastics in an effort to restore sight in patients where other implant approaches have failed or are prone to infection.
Stanford University Chemical Engineering Professor Curtis Frank and his students have produced blended polymer hydrogels with water content of 60% to 90% that are extremely resistant to wear and fracture and possess tensile strengths up to 20 times stronger than their component single networks on their own.
Importantly, the materials are optically clear and highly permeable to glucose, the primary nutrient for the cells of the cornea. Hydrogels are obtained by interpenetrating a tightly cross-linked polyethylene glycol (PEG) network with a loosely cross-linked polyacrylic acid network.
Researchers at Germany's Fraunhofer Society, working in collaboration with the Aachen Center of Technology Transfer, are also developing artificial corneas using highly water absorbent polymers....