Fabrication and Operation of Microfluidic Hanging-Drop Networks

Abstract

The hanging-drop network (HDN) is a technology platform based on a completely open microfluidic network at the bottom of an inverted, surface-patterned substrate. The platform is predominantly used for the formation, culturing, and interaction of self-assembled spherical microtissues (spheroids) under precisely controlled flow conditions. Here, we describe design, fabrication, and operation of microfluidic hanging-drop networks.

Recent Progress in Lab-On-a-Chip Systems for the Monitoring of Metabolites for Mammalian and Microbial Cell Research

“…Misun et al reported a microfluidic device integrated with electrochemical lactate biosensor for the monitoring of human colon cancer microspheroid cultures from a hanging drop [100]. The hanging drop network was extensively characterised and optimised for the spheroid culture and analysis in previous studies [114,115]. The design for the electrochemical biosensors is shown in Figure 4A, and the assembly of whole device is shown in Figure 4C.…”

A Microfluidic Hanging-Drop-Based Islet Perifusion System for Studying Glucose-Stimulated Insulin Secretion From Multiple Individual Pancreatic Islets

“…The microfluidic hanging-drop chip was designed as an open microfluidic system (Frey et al, 2014;Misun et al, 2018Misun et al, , 2020. Figure 2A displays the layout and dimensions of the chip and a cross-sectional view of an islet drop with an islet microtissue.…”

“…The new generation of hanging-drop-based islet perifusion platforms was designed to further reduce operational complexity and to increase experimental throughput. The new system features a microfluidic network of four parallel hanging drops – each hosting an individual pancreatic islet, and a needle-type control drop that automatically adjusts and equilibrates the size of all hanging drops in the microfluidic network ( Birchler et al, 2016 ; Misun et al, 2018 ). The system was designed to maintain slip-boundary conditions at the air-liquid interface for rapid liquid turnover and to enable aliasing-free sampling of the release dynamics of all four individual islets.…”

Advances in cancer modeling: fluidic systems for increasing representativeness of large 3D multicellular spheroids

“…The medium perfusion permits substance dosage and nutrient supply, thus extending the in-culture maintenance of the spheroids. Moreover, capillary valves within the network enable the reconfiguration of drop interconnections and consequent different multi-aggregates experimental settings [8]. The system has recently been commercialized by InSphero AG under the name of 3D InSight Microtissues, namely an assay-ready system consisting of HCN-derived Akura plates, in 96- or 384-well format, which already incorporates preformed microtissues in different formats (InSphero AG).…”

“…(TissUse GmbH, Berlin, Germany) [7]; (b) the microfluidic hanging-drop network (HDN) by Misun etal . (InSphero AG, Schlieren, Switzerland) [8]; (c) the multicompartmental modular bioreactor (MCmB) by Mazzei etal . (commercialized by Kirkstall Ltd, Rotherdam, UK and recently by IVTech Srl, Massarosa, Italy) [9].…”