Spatial and temporal control of cell aggregation efficiently directs human pluripotent stem cells towards neural commitment

Abstract

3D suspension culture is generally considered a promising method to achieve efficient expansion and controlled differentiation of human pluripotent stem cells (hPSCs). In this work, we focused on developing an integrated culture platform for expansion and neural commitment of hPSCs into neural precursors using 3D suspension conditions and chemically‐defined culture media. We evaluated different inoculation methodologies for hPSC expansion as 3D aggregates and characterized the resulting cultures in terms of aggregate size distribution. It was demonstrated that upon single‐cell inoculation, after four days of culture, 3D aggregates were composed of homogenous populations of hPSC and were characterized by an average diameter of 139 ± 26 μm, which was determined to be the optimal size to initiate neural commitment. Temporal analysis revealed that upon neural specification it is possible to maximize the percentage of neural precursor cells expressing the neural markers Sox1 and Pax6 after nine days of culture. These results highlight our ability to define a robust method for production of hPSC‐derived neural precursors that minimizes processing steps and that constitutes a promising alternative to the traditional planar adherent culture system due to a high potential for scaling‐up.