A clear cornea is essential to sharp vision, and any damage to it can lead to blindness. The reasons can include acid burns, chronic inflammation, infections, or a shortage of limbal stem cells. In many cases only a transplant can help, but donor corneas are rare. Seven thousand patients are waiting for treatment in Germany alone. By creating artificial corneas on the basis of fine-knit polymers, the Aachen Center for Technology Transfer ACTO e. V., working together with several partners, has greatly raised expectations. The research work has also been further developed as part of the "ArtCornea®" project of the Fraunhofer IAP.
The artificial cornea – or "keratoprosthesis" – is available as either a temporary or permanent implant. The temporary implant TempKPRO is used for First Aid or as a transitory measure until a donor organ is available, and is already in practical application.
To produce the base material for the permanent implant TexKPRO, which is currently in the clinical study phase, polymer fibers – specifically, polyvinylidene fluoride (PVDF) filaments – are processed into extremely finely-woven fabric. TexKPRO thus lasts a lifetime. The Aachen Center for Technology Transfer ACTO e. V. co-developed the permanent implant together with the German Wool Research Institute (DWI). In addition to extremely fine polyvinylidene fluoride, the implant contains silicon as its second component. This results in the achievement of stretch characteristics that almost correspond to the surrounding human tissue, and has a positive effect on the growing-in process of the textile implant.
Further partners of the Aachen Center for Technology Transfer ACTO e. V. are the University Clinic of Aachen, the Eye Clinic of Cologne-Merheim and the Institute for Textile Technology Aachen (ITA) of the Rhine-Westphalian Technical University Aachen (RWTH), as well as Dr. Joachim Storsberg and his team from the Fraunhofer Institute for Applied Polymer Research IAP in Potsdam.
Dr. Joachim Storsberg has another important project ahead of him in the textile cornea field: ArtCornea®. As part of this ZIM* project, existing problems are being tackled consistently and thoroughly. In addition to a further development of TexKPro, the implant with textile haptics, the project has also produced the new permanent implant ArtCornea®.
Integration into human tissue takes place far more efficiently with ArtCornea® – thanks to a new coating for the PVFD fibers. PVFD is chemically inert in its reactions – a characteristic which, though fundamentally positive, makes it harder for cells to grow. So Dr. Joachim Storsberg at the Fraunhofer IAP decided to give the PVFD textile a 'surface modification'.
For ArtCornea®, a hydrogel material was coated with a reactive molecule. According to Dr. Storsberg there are several more benefits from this textile innovation and from ArtCornea®: "The textile haptics are exemplary because they can absorb and distribute mechanical forces far more effectively. With ArtCornea, the material is also somewhat softer. This improves the anchoring effect, and displays good tissue integration."
A further ArtCornea® partner, in addition to ACTO and the Eye Clinic of Cologne-Merheim, is the Martin Luther University of Halle-Wittenberg.
*ZIM = Central Innovation Program for Small and Medium-Sized Enterprises, an initiative of the Federal German Ministry of Industry and Technology
In 2009, several patients who had rejected human donor corneas had specially-developed keratoprostheses implanted, and today they have still developed no complications at all. This is a reason to be confident for up to 39.8 million blind people and 285.3 million partially-blind people all over the world. In the industrialized nations these persons are frequently well integrated, also in terms of education and profession, but the global situation paints an entirely different picture: 90 percent of blind children have no access to a school education, and 80 percent of blind adults are unemployed because of a lack of educational opportunity.
Many of these people could be helped in the very near future if the textile cornea continues to establish itself, becoming economically feasible and finding application worldwide.
In addition to providing suitable products for the manufacture of polyvinylidene fluoride filaments, Groz-Beckert's Technology and Development Center (TEZ) is also the ideal location for bringing projects such as the textile cornea to maturity together with partners. The experts at the TEZ look forward to a discussion with you.
Groz-Beckert thanks the following for providing images and information material: © ZIM Project ArtCornea: ACTO e.V., Fraunhofer Institute for Applied Polymer Research (IAP) in Potsdam, Schmidt Intraocularlinsen GmbH, Prof. Dr. Norbert Schrage, Dr. Joachim Storsberg, and Dr. Arthur Messner.