Biophysical subsets of embryonic stem cells display distinct phenotypic and morphological signatures

• Authors: Tom Bongiorno, Georgia Institute of Technology; Jeremy Gura, Georgia Institute of Technology; Priyanka Talwar, Georgia Institute of Technology; Dwight Chambers, Georgia Institute of Technology; Katherine M. Young, Georgia Institute of Technology; Dwight Arafat, Georgia Institute of Technology; Gonghao Wang, Georgia Institute of Technology; Emily L. Jackson-Holmes, Georgia Institute of Technology; Peng Qiu, Georgia Institute of Technology; Todd McDevitt, Emory University; Todd Sulchek, Georgia Institute of Technology
• Journal Title: PLoS ONE
• Volume: Volume 13, Number 3
• Publisher: Public Library Science | 2018-03-08, Pages e0192631-e0192631
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1371/journal.pone.0192631
• Subjects: Engineering, Biomedical; Biology, Molecular; Biology, Cell; Engineering, Mechanical
• Keywords: Science & Technology; Multidisciplinary Sciences; Science & Technology - Other Topics; Self renewal; Viscoelastic properties; Precursor cells; PCR efficiency; Lamin A/C; In vitro; Differentiation; Mouse; Expression; Mechanics

Abstract

The highly proliferative and pluripotent characteristics of embryonic stem cells engender great promise for tissue engineering and regenerative medicine, but the rapid identification and isolation of target cell phenotypes remains challenging. Therefore, the objectives of this study were to characterize cell mechanics as a function of differentiation and to employ differences in cell stiffness to select population subsets with distinct mechanical, morphological, and biological properties. Biomechanical analysis with atomic force microscopy revealed that embryonic stem cells stiffened within one day of differentiation induced by leukemia inhibitory factor removal, with a lagging but pronounced change from spherical to spindle-shaped cell morphology. A microfluidic device was then employed to sort a differentially labeled mixture of pluripotent and differentiating cells based on stiffness, resulting in pluripotent cell enrichment in the soft device outlet. Furthermore, sorting an unlabeled population of partially differentiated cells produced a subset of “soft” cells that was enriched for the pluripotent phenotype, as assessed by post-sort characterization of cell mechanics, morphology, and gene expression. The results of this study indicate that intrinsic cell mechanical properties might serve as a basis for efficient, high-throughput, and label-free isolation of pluripotent stem cells, which will facilitate a greater biological understanding of pluripotency and advance the potential of pluripotent stem cell differentiated progeny as cell sources for tissue engineering and regenerative medicine.