DurImplant - Analysis of implant behavior after bioreactor maturation in vitro

• Applicants: Professor Dr. Wilhelm Jahnen-Dechent; Professor Dr.-Ing. Ulrich Steinseifer
• Subject Area: Fluid Mechanics ; Biomaterials ; Medical Physics, Biomedical Technology
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 403041552

The aim of project P05 is the development of an in vitro methodology for the investigation of the durability of biohybrid implants with focus on the propensity to calcification as a decisive limiting factor of the implant lifetime and function. The issue of calcification propensity and its prediction and prevention is already of great importance in avital bioprosthetic heart valves. Addressing this issue, we pose the hypothesis that biohybrid heart valve prostheses with a vital, functionally active endothelium are a natural barrier for calcification. We will test this hypothesis in a biomimetic test environment as close to reality as possible. CVE already has a dynamic durability test system for testing avital bioprosthetic heart valves, which is however premised on a purely mechanical and physicochemical basis, and therefore does not offer a suitable test environment for cellularized material, neither from a physiological nor cytotoxicological point of view. In the first project phase, cell-compatible fluids as well as a physiological test environment with regard to pH, temperature and flow conditions were developed, which also allows the online detection of emerging calcifications on biohybrid implants.In the second project phase, the flow chamber already developed in the first project phase will be further expanded and enhanced with cell assays. This will make it possible to assess implant stability and calcification tendency on a small scale. For that, the already established Fetuin-A-imaging will be further refined in order to be able to make quantitative statements on calcification. In addition, the health of the cells as well as the endotheliazation of the biohybrid implants will be analyzed. The knowledge gained from the cell analyses will be used to improve the testing. This will provide the project partners with direct feedback on the behavior of the developed implants as well as cells on top of these implants. In parallel with the further development of the flow chamber test system, a test system for full-size biohybrid implants is also being developed. This will allow testing of fatigue strength and calcification tendency of complete, full-size implants in a sterile environment with conditions similar to the in vivo situation. Implants are installed in the laboratory under sterile conditions and the test chamber is filled. Furthermore, the test system will be further developed to also allow online imaging and continuous analysis of the implant.

• DFG Programme: Research Grants
• Co-Investigator: Dr. Johanna Clauser