Human tissue models instead of animal experiments? What is already possible for some questions still faces major hurdles for more complex contexts and applications. In a joint project of the Max Planck Institute for Polymer Research, Mainz, and the Translational Center for Regenerative Therapies at the Fraunhofer Institute for Silicate Research ISC, Würzburg, scientific principles and biomaterials for the standardized production of valid tissue models are to be developed.