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In tissue engineering, the scaffold material must eventually degrade leaving behind only regenerated tissue. For hydrogels that serve as cell encapsulation platforms, hydrogel degradation must closely match tissue growth. This link is particularly challenging because many of the extracellular matrix (ECM) molecules that are secreted by encapsulated cells are much larger than the mesh of the hydrogel. In other words, the hydrogel mesh that surrounds each cell acts as a barrier to diffusion of the newly secreted ECM molecules and ultimately inhibits tissue growth. As the hydrogel degrades, the size of the mesh increases. However for the large ECM molecules, the hydrogel must reach near complete dissolution for these molecules to diffuse. There is, therefore, a narrow window in the hydrogel-to-tissue transition. Our group designs hydrolytically and enzymatically degradable hydrogels to control degradation temporally and spatially. We have extensively studied hydrogel degradation for cartilage tissue engineering showing the impact of degradation mechanism and degradation behavior on tissue formation. We recently identified novel mechanisms by which cells interact with free-radicals during hydrogel formation that leads to spatial variations in hydrogel crosslinking and can improve tissue growth. In collaboration with Prof. Franck Vernerey, we have developed mathematical models to aid in the design of hydrogel degradation, which is enabling a personalized strategy for tuning hydrogel degradation that is patient-specific. When combining hydrogels with stiff 3D printed structures to support mechanical forces, the 3D structure must also be designed to degrade. However, it's critical to maintain the mechanical properties and hence the mechanical support during degradation. Thus, we are also designing novel monomers and resins to tune the degradation behavior of 3D printed materials. Our overarching goal is to develop degradable biomaterials that both provide the needed mechanical support while simultaneously promoting tissue growth.