Spheroids (Purple) Fusing Around Crosslinked Microgels (Green)

This rendering depicts stem cell spheroids (purple) and microgels (green) mixed together, which we call 'granular composites'. The composites have numerous advantages over traditional cell-encapsulated nano porous hydrogels, such as having microporosity that enhanced nutrient diffusion and allows stem cells spheroids to fuse and deposit cartilage proteins without the need to degrade the microgels first. The microgels also provide an essential purpose, inital stability. If these spheroids were mixed alone, they would fuse together and collapse into a large ball to reach an energy minimum state. The microgels can be bonded together (covalently, blue) with visible light to act as physical barriers to spheroid collapse. We care about this because if used to treat a defect, we don't want the treatment to shrink in the defect after injection and stabilization with light. 

Publication: https://doi.org/10.1002/adma.202312226