Microfluidic integration of the single cell adhesion dot array (SCADA) technology for the real-time quantification of cell affinity

Abstract

Understanding cell affinity to substrates and biomolecules is of great importance in disease research, drug development and general cell biology studies. Established techniques to measure cell affinity involve either expensive and cumbersome techniques that quantify the binding between cells and proteins in suspension (e.g., flow cytometry), or indirect methods that quantify the amount of cells on a surface (e.g., impedance sensors). Novel approaches exploit microtechnologies to reduce the number of cells needed and reach single cell resolution. However, the examples so far fail to provide a simple device to measure cell affinity with single cell resolution that can be adapted to several purposes and cell biology laboratories. Herein, we describe a tool for the real-time optical monitoring of cell affinity. It is based in the integration of the cell-based biosensing platform Single Cell Adhesion Dot Arrays (SCADA) into a microfluidic device. These SCADA-on-chip devices were used to successfully quantify and differentiate the affinity of human hair follicle-derived Mesenchymal Stem Cells towards several molecules with a range of cell-adhesive capabilities, which could be resolved in less than 20 min. The developed device constitutes a self-contained, single-use and user-friendly cell-based sensor for the quantification of cell affinity. Moreover, its multiple applications could be transferred to a great range of laboratories, whilst requiring a much reduced amount of reagents, cells and time to complete the assays.