Stem Cell Sorting: Exploiting Elastic and Viscoelastic Cell Properties

Investigator: Nicholas Labriola

Basis: Heterogeneity in stem cell populations poses a major hurdle for cell-based therapies; enriching these populations is essential for success. Enrichment has conventionally been performed by exploiting differences in surface markers using flow cytometry. However, information on specific surface biomarkers for certain multipotent lineages, such as mesenchymal stem cells (MSCs), is scarce, making it difficult to identify and separate these cells from heterogeneous populations. Improvements to stem cell enrichment might be feasible by exploiting other intrinsic cell properties, such as mechanical differences among cells with varying multi-lineage potentials. The goal of this study is to demonstrate the feasibility of sorting cells by differences in elastic and viscoelastic properties.

Sorting Methods: Initial sorting was performed with the use of an equation derived from the behavior of cells in micropipette aspiration. This allowed us to estimate translation time of cells with known mechanical properties through a filter membrane. Validation experiments utilized cell lines to maximize differences in mechanical properties - elastic and viscoelastic properties were determined using atomic force microscopy (AFM). Complexity and efficiency of the system will increase as we move towards microfluidic systems.