Wet, soft, squishy, and tunable

Materials Science Hydrogels are highly cross-linked polymer networks that are heavily swollen with water. Hydrogels have been used as dynamic, tunable, degradable materials for growing cells and tissues. Zhang and Khademhosseini review the advances in making hydrogels with improved mechanical strength and greater flexibility for use in a wide range of applications. Science , this issue p. [eaaf3627][1] [1]: /lookup/doi/10.1126/science.aaf3627