Establishment of physiologically relevant environment for human cell culture and blastoid models

Abstract

In vitro cellular models are crucial to the advancement of our knowledge in both basic and translational biomedical research. Since the1950s, in vitro cellular models have been one of the main methods used to understand human biology both in health and disease. Recent advances in stem cells and regenerative medicine especially in early human development, call for a much-refined cell culture system to accommodate increasingly complex 3D models. Here, I have reevaluated cell culture practices and devised a new approach using updated cell culture standards to grow human blastoids under near-physiological conditions.

I have found that methods utilized to maintain in vitro models have hitherto unknown limitations that limit their full utility, including the constant deviations of environmental factors such as oxygen and pH from physiological values. As human cells grow in vitro, they metabolically act to deoxygenate and acidify their environment, leading to unwanted environmental deviations. I showed that such deviations lead to inflammations and cellular stress in human B cells. To resolve this issue, I have established a system that regulates cellular environments and demonstrated the ability to monitor, control, and maintain cell culture environments.

Using the newly established methods, I have generated scalable 3D human blastoids from single human naïve pluripotent stem cells under near physiological control that can serve as an ethical model for human embryogenesis. These 3D human blastoids would enable scientists to understand early developmental processes and how a single cell can give rise to a whole organism.

All in all, my work sheds light on deficiencies of current cell culture practices and provides a technology that maintains near physiological conditions in laboratory conditions. This newly devised approach will allow us to rigorously model early human development.