A Cardiac Cell Outgrowth Assay for Evaluating Drug Compounds Using a Cardiac Spheroid-on-a-Chip Device

Abstract

Three-dimensional (3D) models with cells arranged in clusters or spheroids have emerged as valuable tools to improve physiological relevance in drug screening. One of the challenges with cells cultured in 3D, especially for high-throughput applications, is to quickly and non-invasively assess the cellular state in vitro. In this article, we show that the number of cells growing out from human induced pluripotent stem cell (hiPSC)-derived cardiac spheroids can be quantified to serve as an indicator of a drug’s effect on spheroids captured in a microfluidic device. Combining this spheroid-on-a-chip with confocal high content imaging reveals easily accessible, quantitative outgrowth data. We found that effects on outgrowing cell numbers correlate to the concentrations of relevant pharmacological compounds and could thus serve as a practical readout to monitor drug effects. Here, we demonstrate the potential of this semi-high-throughput “cardiac cell outgrowth assay” with six compounds at three concentrations applied to spheroids for 48 h. The image-based readout complements end-point assays or may be used as a non-invasive assay for quality control during long-term culture.

3D Co-culture of hiPSC-Derived Cardiomyocytes With Cardiac Fibroblasts Improves Tissue-Like Features of Cardiac Spheroids

“…Outgrown cells were thinly spread out on the flat substrate, while those cells seen on the surface of the spheroid kept a rounded or spindle shape ( Figure 1D). It is possible to make use of outgrowing cells for testing pharmacological compounds, as others have demonstrated (Christoffersson et al, 2018), however, we have put emphasis on spheroids and defined 2D cultures in this study. Opening a spheroid by manually cutting it with a blade provided an opportunity to inspect the interior structure ( Figure 1B).…”

Optical Imaging Approaches to Monitor Static and Dynamic Cell‐on‐Chip Platforms: A Tutorial Review

“…To develop the optical setup, a highly precise focusing and scanning of light on the sample surface followed by an image processing are technical problems. Confocal microscopy is a high‐quality technique for imaging of static platforms such as organ on a chip (Figure c) or spheroid‐on‐a‐chip …”

Microfluidics – Organ-on-chip

“…These cardiac spheroid-on-a-chip devices were coupled with confocal high content imaging and used to determine the correlation between outgrowing cell numbers and drug concentrations. Therefore making them potential candidates for the monitoring of drug effects on long-term cultures [8].…”