Directing Cell Phenotype: Quantitative Single-Cell Migration Assay Leveraging Tunable Extracellular Surfaces

From <i>in vitro</i> cancer research to immunology, single-cell migration assays are among the most common assays for gaining phenotypic insight into the dynamics of adhesion and migration. In general, however, the extracellular environments used in these assays are poorly characterized, which can lead to difficulty interpreting the resulting cellular behavior. Here we introduce a single-cell migration assay which incorporates tunable surfaces that are chemically well-characterized by surface ligand activity (surface activity) quantification. We applied this approach to MDA-MB-231 breast carcinoma cells, measuring single cell morphology, speed, and directionality as a function of cRGD surface activity, controlled via cRGD ligand spacing. Using this approach, we show cell behavior via morphology, migration, and presence of focal adhesions can be directed from amoeboid to mesenchymal-like phenotypes, highlighting tunable surface activity as a reproducible way to direct phenotype.