A robotised 1546 compound screen in a perfused 3D microfluidic angiogenesis assay

Organ-on-a-Chip is a powerful technology driving physiological relevance by utilizing microfluidic techniques. The technology is expected to impact drug development and ultimately replace or reduce animal testing. Since the majority of platform technologies are either based on single chips or small numbers of chips in dedicated surroundings, application for Organ-on-a-chip is largely envisioned in pre-clinical testing, such as preclinical safety, pharmacology or pharmacokinetics. Thus far it was thought that with the advanced complexity of models prevents use in drug discovery studies. The OrganoPlate is an exception to this rule, as it comprises 40 to 96 chips. The microtiter plate footprint renders it fully compatible with automated imaging and robotic handling. In fact, Kane et al. reported automation of the platform for long term maintenance of dopaminergic neurons in a Parkinson’s Disease study (1). High throughput screening applications utilizing Organ-on-a-Chip technology, however have thus far not been reported.

Here we report a 1546 compound screen on a 3D angiogenic sprouting assay. We utilize a newly developed platform, the OrganoPlate 3-lane 64, which comprises 64 chips underneath a microtiter plate. Similar to other versions of the OrganoPlate platform, it utilizes surface tension techniques to stratify extracellular matrix gels and tissue layers, and employs passive leveling between reservoirs for inducing flow. Each chip comprises a gel lane and is flanked by two perfusion lanes. Human Umbilical Vein Endothelial Cell (HUVEC) microvessels were grown against a collagen gel according to previously reported protocols (2). The effect of a small molecule protein kinase inhibitor library of 1546 compounds was assessed on the angiogenic sprouting behavior of the vessels.  The micro-vessels were exposed to an optimized cocktail of angiogenic factors in conjunction with the compound utilizing automated liquid handling. Readouts including sprouting length, number of sprouts, nuclei distance, and were acquired high content imaging (Molecular Devices, ImageXpress Micro Confocal). The screen yielded a limited number of hits that either enhanced or inhibited angiogenic capacity. The OrganoPlate 3-lane 64 showed considerable benefit over its predecessor, the OrganoPlate 3-lane 40, not only due to the increased density of chips, but also its 8-well pipette pitch for functionally similar inlets and outlets. This is the first time that Organ-on-a-Chip is reported to be utilized in a full blown library screen, opening up the route towards early drug screening on tissue models of unrivalled physiological relevance.

1.          K. I. W. Kane et al., Sci. Rep. 9, 1–12 (2019).

2.          V. Van Duinen et al., Sci. Rep. 7, 1–11 (2017).