The overall objective of the subproject is the basic and expanded representation of a comprehensive cyto- and biocompatibility of the implants and new surfaces manufactured by the project partners. The results will be put into the overall context of the characterization, manufacturing and interdisciplinary evaluation of permanent implants. Furthermore, the conclusions will be implemented in the discussions and evaluation of the different working groups. The subproject can be divided into four objectives that build on one another. The first objective is the representation of a sufficient basic cytocompatibility of the implants and surfaces. Thereby, incompatible materials can be excluded from further and more complex investigations at an early time point. The tests are followed by more complex cytocompatibility analysis using additional cell types in co- and multi-cultures as well as investigation of hemocompatibility. The most promising materials and surfaces are tested in small animal models (subcutaneous, calotte) with subsequent histopathological, histomorphometric, immunohistochemical and tomography (μCT) analysis. The results are compared and correlated with the preceding results of the other work packages. The fourth goal is the introduction of a biological test bench which aims to simulate the In-vivo-situation. Thereby, the results from the test bench will be correlated with the results of the cyto- and biocompatibility analysis. Finally, recommendations for the future reduction of animal experiments will be implemented on the basis of the overall results and correlations.