Tissue regeneration is regulated by the cellular microenvironment, e.g. the extracellular matrix. Here, sulfated glycosaminoglycans (GAG), are of vital importance interacting with mediator proteins and influencing their biological activity. Hence, they are promising candidates for controlling tissue regeneration. This review addresses recent achievements regarding chemically modified GAG as well as collagen/GAG-based coatings and hydrogels including (i) chemical functionalization strategies for native GAG, (ii) GAG-based biomaterial strategies for controlling cellular responses, (iii) (bio)chemical methods for characterization and iv) protein interaction profiles and attained tissue regeneration in vitro and in vivo. The potential of GAG for bioinspired, functional biomaterials is highlighted.