Profiling Cell-Matrix Adhesion Using Digitalized Acoustic Streaming.

Profiling the kinetics of cell-matrix adhesion is of great importance to understand many physiological and pathological processes such as morphogenesis, tissue homeostasis, wound healing, and tumorigenesis. Here, we developed a novel digital acoustofluidic device for parallel profiling cell-matrix adhesion at the single-cell level. By introducing a localized and uniform acoustic streaming into an open chamber microfluidic device, the adherent cells within the open chamber can be detached by the streaming-induced Stokes drag force. By digitally regulating pulsed acoustic power from a low level to high levels, the hundreds of adherent cells can be ruptured from the fibronectin-coated substrate accordingly, and their adhesive forces (from several pN to several nN) and kinetics can be determined by the applied power and cell incubation time. As a proof-of-concept application for studying cancer metastasis, we applied this technique to measure the adhesion strength and kinetics of human breast cancer cells to extracellular matrix such as fibronectin and compared their metastatic potentials by measuring rupture force of cancer cells representing malignant (MCF-7 cells and MDA-MB-231 cells) and non-malignant (MCF-10A cells) states. Our acoustofluidic device is simple, easy for operation, and capable of parallelly measure hundreds of individual cells' adhesion forces with a resolution at the pN level. Thus, we expect this device could be widely used for both fundamental cell biology research as well as the development of cancer diagnostics and tissue engineering technologies.