Next gen biomaterials yield artificial cornea

Based on a polymer with high water-absorbent properties, the ArtCornea device is designed to help patients whose cornea has become clouded, as well as those not who would not tolerate a donor cornea. "A great many patients suffering from a range of conditions will be able to benefit from our new implant," said project manager Dr Joachim Storsberg, from the Fraunhofer Institute for Applied Polymer research. The Fraunhofer team created the ArtCornea by adding a novel surface coating to the base polymer material to ensure anchorage in host tissue and functionality of the optic. The haptic edge was chemically altered to encourage local cell growth. These cells then graft to the surrounding human tissue, which is essential for anchorage of the device in the host tissue. The researchers aimed to enlarge the optical surface area of the implant in order to improve light penetration beyond what had previously been possible. "Once ArtCornea is in place, it is hardly visible, except perhaps for a few stitches," noted Dr Storsberg. "It's also easy to implant and doesn't provoke any immune response." The researchers have also made a chemically and biologically inert base material biologically compatible for another artificial cornea called the ACTO-TexKpro. They achieved this by selectively altering the base material, polyvinylidene difluoride, by coating the fluoride synthetic tissue with a reactive molecule. This is said to allow the patient's cornea to bond together naturally with the edge of the implant, while the implant's inner optics, made of silicon, remain free of cells and clear. Both artificial retinas have been tested in vivo in several rabbits. The researchers reported that after a six month healing process, the implanted prostheses were accepted without irritation and securely anchored within the eye. Further trials are now taking place.