3D Printed Lab-on-a-Chip Platform for Chemical Stimulation and Parallel Analysis of Ion Channel Function

Abstract

Functional imaging has been a widely established method for the assessment of ion channel function in vitro. Conventional infrastructure used for in vitro functional analysis of ion channels is typically proprietary, non-customizable, expensive, and requires a high level of skill to use and maintain. 3D desktop printing, which is employed in the rapid prototyping field, allows for quick engineering of alternatives to conventional imaging infrastructure that are customizable, low cost, and user friendly. Here, we describe an ultra-low-cost microfluidic lab-on-a-chip (LOC) device manufactured using acrylonitrile butadiene styrene (ABS) for in vitro functional imaging of ion channels that can quickly and easily be reconstructed using three-dimensional (3D) desktop printing. The device is light weight (<5 g), small (20 mm × 49 mm), and extremely low cost (<EUR 1). We simulate fluidics within the printed channels and assess the suitability of the engineered chamber to generate homogeneous mixtures during solution exchange. We demonstrate the usability of the 3D printed microfluidic device in a case study using Fluo-4-loaded human embryonal kidney-derived (HEK293) cells, recombinantly expressing the capsaicin receptor, transient receptor potential vanilloid receptor type 1 (TRPV1), as a model system. In the case study, we confirm its applicability to solution exchange for chemical stimulation and parallel functional time-lapse fluorescence microscopy-based calcium imaging. We assess the suitability of ABS for culturing HEK293 cells inside the microfluidic LOC, based on qualitative analysis of microscopic transmission light images of ABS-exposed HEK293 cells and confirm the previously reported biocompatibility of ABS. To highlight the versatility of the 3D printed microfluidic device, we provide an example for multiplication of the shown concept within a 3D printed multichannel microfluidic LOC to be used, for example, in a higher throughput format for parallelized functional analysis of ion channels. While this work focusses on Ca2+ imaging with TRPV1 channels, the device may also be useful for application with other ion channel types and in vitro models.

Guided accumulation of active particles by topological design of a second-order skin effect

“…Our work establishes a strategy to design circuits that spontaneously break detailed balance to guide and accumulate active matter, enforced by robust out-of-equilibrium topological phenomena. This design strategy and the 3D printing capabilities, permit to envision 3D extensions where the accumulation of particles is guaranteed by non-planar surfaces (e.g., using ramps, or different levels) 55 or by implementing dynamic topographical pathways topology 56 .…”

3D In Vitro Human Organ Mimicry Devices for Drug Discovery, Development, and Assessment

“…Using cell morphology imaging during chemical stimulation with capsaicin, the fluorescence intensity showed a consistent increase with an increase in the intracellular calcium concentration. The authors concluded that the model was reliable for ion analysis [63].…”

A Review of Microfluidic Experimental Designs for Nanoparticle Synthesis

“…An interesting device was also realized by Aschenbrenner et al [ 102 ], who employed 3D printing of acrylonitrile butadiene styrene to create ultra-low-cost microfluidic platforms. The design is made of two 3D printed parts, namely the main compartment and an outlet connector for drainage tubing ( Figure 29 ).…”

“…The green color inside the cell chamber indicates a mixing ration of approximately 0.5, and thus demonstrates homogeneous distribution of efficiently mixed solutions. Reprinted from an open-access source [ 102 ].…”