Research Associate New York University Abu Dhabi Kyoto-shi, Japan
Abstract: Human blastoids provide a promising model for investigating early embryonic development and pregnancy failures—challenges that were previously unattainable to address without the use of human embryos. However, recent protocols for blastoid generation have predominantly relied on human naïve pluripotent stem cells (PSCs). Here, we present a new approach to produce blastoids from the more stable primed hPSC state. The method employs a thermoresponsive hydrogel composed of poly(N-isopropylacrylamide) and polyethylene glycol (PNIPAAm-PEG) to mimic the physical characteristics of the zona pellucida. The hydrogel provides gentle mechanical cues to hPSC aggregates without requiring cell adhesion, thereby preventing cell migration into the gel. The sol-gel transition, mediated by temperature control, facilitates blastoid placement and retrieval at low temperatures (20°C), followed by culture at 37°C. Fine-tuning the hydrogel’s viscoelastic properties and reducing cell adhesiveness proved essential for efficient blastoid formation. Single-cell RNA sequencing and RNA velocity analysis revealed the emergence of the three principal cell lineages of the blastocyst, underscoring the physiological relevance of the model. This advance improves the capacity to recapitulate early human embryonic development in vitro and offers a promising platform for future studies on human embryogenesis and reproductive biology.
Funding Source: The Japan Society for the Promotion of Science (17H02083, 21H01728 and 23K17345) New York University Abu Dhabi (NYUAD) Faculty Research Fund (AD366 to KK)
