Droplet microarray: miniaturized platform for rapid formation and high-throughput screening of embryoid bodies

Abstract

Stem cells are influenced by various factors present in their in vivo microenvironment, such as interactions with neighboring cells, the extracellular matrix or soluble molecules. This demonstrates the high complexity of the in vivo microenvironment. Hence, many advances have been made in developing 3D screening models mimicking this complexity and the in vivo-like state in order to ensure more biomedically relevant investigations in drug discovery. In the field of stem cell research embryoid bodies are often used as relevant 3D systems. Embryoid bodies are embryonic stem cell aggregates that recapitulate the early embryonic development and that can differentiate into derivatives of the three germ layers. Embryoid bodies enable the investigation of processes underlying embryonic development, tissue generation and identification of drugs with developmental toxicity. The ability to perform high-throughput screenings using embryoid bodies could be extremely important to accelerate the progress in the field of stem cell research and embryonic development. To date, there are no simple methods to create high-density microarrays of embryoid bodies that further enable their high-throughput screening important for biomedical research. Here we demonstrate a new method that enables formation and high-throughput screening of embryoid bodies in arrays of defined, separated microdroplets. Using the superhydrophobic-hydrophilic micropattern of the droplet microarray, we demonstrate rapid and facile one-step formation of a dense array of multiple droplets containing homogeneous, single embryoid bodies. Thorough characterization of the influence of the initial cell number on embryoid body size, roundness and distribution was performed. We applied the embryoid body microarray to screen 774 FDA-approved compounds, identifying compounds with developmental toxicity such as mycophenolate mofetil or embryonic lethality such as eptifibatide. This work demonstrates the potential of the droplet microarray for the rapid formation of high-density microarrays of single embryoid bodies and their high-throughput drug screenings.

Facile One Step Formation and Screening of Tumor Spheroids Using Droplet‐Microarray Platform

“…Recently, we developed the Droplet Microarray (DMA), a miniaturized platform for cell‐based high‐throughput screenings . The Droplet Microarray consists of an array of hydrophilic spots on superhydrophobic background and exhibits extreme contrast in wettability between these areas.…”

“…[30,31] Recently, we developed the Droplet Microarray (DMA), a miniaturized platform for cell-based high-throughput screenings. [35][36][37][38][39][40] The Droplet Microarray consists of an array of hydrophilic spots on superhydrophobic background and exhibits extreme contrast in wettability between these areas. Due to this extreme contrast a high-density array of homogeneous, separated and stable nanodroplets can be formed on the surface of the Droplet Microarray.…”

Direct-Write Bioprinting Approach to Construct Multilayer Cellular Tissues

“…The technique is based on a programmable noncontact piezoelectric inkjet bioprinter with a resolution of 5 µm and a minimum deposition volume of 300 pL. Such a system has been frequently applied in researches, especially for ultra-low volume liquid handling of nanoparticles (Scherbahn et al, 2016), drugs (Tronser et al, 2018), and biomolecules, such as proteins (Kilb et al, 2019) and antibodies (Marquette et al, 2012;Schulz et al, 2019).…”

Miniaturized Drug Sensitivity and Resistance Test on Patient-Derived Cells Using Droplet-Microarray

“…We showed that by using the DMA platform and only 100 cells and 300 times fewer compounds and reagents, we obtained the same results as if we had employed conventional 384-well plates and 20,000 cells per each well. We have demonstrated our system in 2D, however, as we have previously shown that the DMA platform is compatible with culturing cells in 3D environments by means of scaffolds 34,35 or by promoting the self-organization of cells. 35 The possibility of culturing cells in 3D gives rise to even more physiologically relevant applications using primary patient-derived cells.…”

“…We have demonstrated the use of the DMA platform for the screening of cells of adherent 30,33 and suspension 29 nature in 2D, as well as in 3D environments. 34,35 In this paper, we have extended application of our miniaturized platform for the miniaturized DSRT on suspension primary patient-derived CLL cells. By using the DMA platform, we were able to reduce the consumption of cells by a factor of 200 compared with 384-well plates.…”