BaroFuse, a novel pressure-driven, adjustable-throughput perfusion system for tissue maintenance and assessment

Abstract

ObjectivesMicrofluidic perfusion systems are used for assessing cell and tissue function while assuring cellular viability. Low perfusate flow rates, desired both for conserving reagents and for extending the number of channels and duration of experiments, conventionally depend on peristaltic pumps to maintain flow yet such pumps are unwieldy and scale poorly for high-throughput applications requiring 16 or more channels. The goal of the study was to develop a scalable multichannel microfluidics system capable of maintaining and assessing kinetic responses of small amounts of tissue to drugs or changes in test conditions.MethodsHere we describe the BaroFuse, a novel, multichannel microfluidics device fabricated using 3D-printing technology that uses gas pressure to drive large numbers of parallel perfusion experiments. The system is versatile with respect to endpoints due to the translucence of the walls of the perifusion chambers, enabling optical methods for interrogating the tissue status. The system was validated by the incorporation of an oxygen detection system that enabled continuous measurement of oxygen consumption rate (OCR).ResultsStable and low flow rates (1–20 μL/min/channel) were finely controlled by a single pressure regulator (0.5–2 psi). Control of flow in 0.2 μL/min increments was achieved. Low flow rates allowed for changes in OCR in response to glucose to be well resolved with very small numbers of islets (1–10 islets/channel). Effects of acetaminophen on OCR by precision-cut liver slices of were dose dependent and similar to previously published values that used more tissue and peristaltic-pump driven flow.ConclusionsThe very low flow rates and simplicity of design and operation of the BaroFuse device allow for the efficient generation of large number of kinetic profiles in OCR and other endpoints lasting from hours to days. The use of flow enhances the ability to make measurements on primary tissue where some elements of native three-dimensional structure are preserved. We offer the BaroFuse as a powerful tool for physiological studies and for pharmaceutical assessment of drug effects as well as personalized medicine.

An Immobilized Enzyme Reactor for Spatiotemporal Control over Reaction Products

“…This method can be applied to a wide variety of channel designs as well as in applications outside of microfluidics such as single cell analysis, nanoparticle synthesis, and soft robotics . Future work may use 3D printing to create the entire microfluidic device, as described by Folch and co‐workers …”

“…[49][50][51] Future work may use 3D printing to create the entire microfluidic device, as described by Folch and co-workers. [52,53] Small 2018, 14,1800923…”

Fluidics system for resolving concentration-dependent effects of dissolved gases on tissue metabolism

“…Liver pieces from rats were prepared as previously described ( Rountree et al, 2016 ). Ten pieces (about 0.25 × 1 mm [mass = 2.5–3.5 mg per piece]) were loaded into each tissue perifusion chamber without succinate, or four pieces for chambers with succinate for each analysis.…”

PiFlow: A Biocompatible Low-Cost Programmable Dynamic Flow Pumping System Utilizing a Raspberry Pi Zero and Commercial Piezoelectric Pumps

“…There have been numerous attempts made recently by academics to address some of these limitations [17][18][19][20][21][22][23][24][25][26][27][28] . Examples include an open-source syringe pump 20 , a low-cost syringe pump 21 , and a scalable pumping system using a Braille display as an actuator 29,30 .…”

“…There have been numerous attempts made recently by both academics and commercial entities to address some of these limitations [16][17][18][19][20][21][22][23][24][25][26][27] . Here we present a microfluidic pumping platform designed to offer greater experimental flexibility, ease of assembly, high scalability and customized flow-rate programmability compared to other currently available commercial and academic systems.…”