In order to understand alterations of extracellular matrix properties under compromised conditions and consequences for regeneration, Petersen and Knaus will investigate extracellular matrix coding and reading in their project. They will elucidate how information encoded in the extracellular matrix influences cell function in the context of bone regeneration. Specifically, they aim at deciphering alterations of the here-defined "matrix code" under compromised conditions related to aging (altered immune status, bone marrow adiposity) in vitro. They hypothesise that precursor cells, if recruited from a compromised bone marrow niche to a bone defect would deposit a compromised extracellular matrix that is modulated additionally by the immune system. The resulting compromised extracellular matrix in turn alters progenitor cell function and thereby entails an impaired healing pathway.