Three-dimensional cell culture in droplets: From multilevel cytometry to tissue engineering

Three-dimensional (3D) cell cultures are rapidly emerging as a promising format to explore biological functions, for a wide range of applications such as drug screening, personalized cancer diagnostics, or tissue engineering for cellular therapy. 3D spheroids offer an attractive format in which the cells adhere together through the extracellular matrix that they secrete. However it is still impossible to acquire large sets of detailed measurements on the 3D cultures, such as those afforded by flow cytometry for individual cells, without breaking the spheroids. Here we present a microfluidic approach to form the spheroids and culture them on a single chip, by leveraging droplet microfluidic methods. The device allows the formation, culture, stimulation, and observation of several hundred spheroids on a single device, in addition to the retrieval of any of them for further off-chip processing. We show how to obtain population, spheroid, and cell-level measurements, as well as applications for drug screening and tissue engineering.