Microgels Enable iPSCs to Assemble, Expand, and Differentiate Into Organoids-From Sizable to High-Throughput.

Organoid research holds tremendous potential for personalized medicine and drug development. However, current limitations include reproducibility issues largely due to the use of biologically derived materials, which are prone to batch-to-batch variations. Here, we report a chemically defined microgel-based method for human induced pluripotent stem cell (iPSC)-based organoid generation, enabling expansion of iPSCs and their subsequent differentiation within one construct across different scales, including compatibility with automated 384-well plate workflows. Chemically defined poly(ethylene glycol) (PEG)-based microgels are produced via parallelized step-emulsification microfluidics, enabling scalable production. This approach leverages the self-organization of iPSCs with microgels to build three-dimensional constructs, driven by robust cell-material interactions achieved through vitronectin-coated PEG microgels. This technology allows the iPSCs to expand and retain their pluripotency, after which they can be differentiated into the three germ layers, providing a suitable platform for organoid differentiation. This was further extended by differentiation into cardiac organoids and retinal photoreceptors to demonstrate two exemplary tissues.