Optimizing Embryoid Bodies and Organoids by Chemical Cytoprotection

Embryoid bodies (EBs) and self-organizing organoids derived from human pluripotent stem cells (hPSC) recapitulate tissue development in a dish and hold great promise for disease modeling and drug development. However, current protocols are hampered by cellular stress and apoptosis during cell aggregation resulting in variability and impaired cell differentiation. Here, we demonstrate that EBs and cerebral organoid model can be optimized by using the CEPT small molecule cocktail, an integrated polypharmacology approach that ensures stress-free cell aggregation and survival. The use of CEPT for only 24 hours during cell aggregation has long-lasting consequences affecting morphogenesis, gene expression, and cellular differentiation. Various methods confirmed that CEPT treatment consistently resulted in higher experimental reproducibility compared to the widely used ROCK inhibitor Y-27632. Immunohistology data also showed that CEPT is universally applicable for successful generation of organoids of various developmental lineages, such as gut and kidney. Collectively, we discovered that viability and cell fitness during cell aggregation are critical quality control determinants that can be enhanced by CEPT, thereby establishing a robust foundation for bioengineering complex tissue models.