ChondroGELesis: Hydrogels to harness the chondrogenic potential of stem cells

Highlights: • Hydrogels are ideal candidates for the engineering of damaged cartilage tissue. • Their biochemical, mechanical and structural properties are readily tuneable. • Optimised hydrogel properties synergistically regulate key chondrogenic pathways. • Cellular content and external stimuli contribute to stem cell chondrogenesis. The extracellular matrix is a highly complex microenvironment, whose various components converge to regulate cell fate. Hydrogels, as water-swollen polymer networks composed by synthetic or natural materials, are ideal candidates to create biologically active substrates that mimic these matrices and target cell behaviour for a desired tissue engineering application. Indeed, the ability to tune their mechanical, structural, and biochemical properties provides a framework to recapitulate native tissues. This review explores how hydrogels have been engineered to harness the chondrogenic response of stem cells for the repair of damaged cartilage tissue. The signalling processes involved in hydrogel-driven chondrogenesis are also discussed, identifying critical pathways that should be taken into account during hydrogel design.