The project group A – Matrix Engineering – comprises the material science/ chemistry oriented projects, including the associated analytics and modelling: The subprojects (TP) A1 and A3 focus on the production of carrier substances and the design of GAG-based biomaterials. Of central importance is the targeted chemical functionalisation of selected GAGs (TP A8, A10), the synthesis of three-dimensional aEZMs (TP A3, A10) and their coupling to carrier substances (immobilisation, delivery systems, scaffolds, TP A1, A4, A10). The aim is to generate multifunctional materials by combining different mechanisms (e.g. sequestration and delivery) with good degradability. This is complemented by the detailed biochemical, biophysical and in silico characterization of the interactions of GAG-derivatives with the bone and skin in the TP A3, A4, A6, A7 and derived statements on the rational design of GAG derivatives, so-called rationally engineered GAG (reGAG).