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Cryan MT, Li Y, Ross AE. Sustained delivery of focal ischemia coupled to real-time neurochemical sensing in brain slices. LAB ON A CHIP 2022; 22:2173-2184. [PMID: 35531656 PMCID: PMC9156565 DOI: 10.1039/d1lc00908g] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Local stimulation of tissue can occur naturally in events like immune-mediated inflammation and focal ischemic injuries in brain and is confined to specific regions within tissue, occurring on various timescales. Making chemical measurements at the exact site of stimulation with current technologies is difficult yet important for understanding tissue response. We have developed a microfluidic device capable of local stimulation of brain slices with minimal lateral spread over time and submillimeter, tunable spatial resolution. This device is compatible with electrochemical measurements to monitor signaling at the site of stimulation over time. The PDMS-based device is three layers and contains a culture well, channel layer, and exit port layer for the channels. Channels with exit ports straddling the stimulus channels and ports were specifically fabricated to focus the stimulus over time. We demonstrated that the device is compatible with fast-scan cyclic voltammetry (FSCV) recording of neurotransmitter release. Localized hypoxia in tissue was verified using Image-iT Green Hypoxia Reagent and coupling this device with FSCV enabled measurement of local dopamine changes at the site of focal ischemia for the first time. This work provides a significant advance in knowledge of local neurochemical fluctuations during sustained tissue injury. Overall, the unique capabilities of the device to deliver sustained localized stimulation combined with real-time sensing provide an innovative platform to answer significant biological questions about how tissues respond at the site of controlled, localized injury and chemical stimulation.
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Affiliation(s)
- Michael T Cryan
- University of Cincinnati, Department of Chemistry, 312 College Drive, 404 Crosley Tower, Cincinnati, OH 45221-0172, USA.
| | - Yuxin Li
- University of Cincinnati, Department of Chemistry, 312 College Drive, 404 Crosley Tower, Cincinnati, OH 45221-0172, USA.
| | - Ashley E Ross
- University of Cincinnati, Department of Chemistry, 312 College Drive, 404 Crosley Tower, Cincinnati, OH 45221-0172, USA.
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2
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Catterton MA, Ball AG, Pompano RR. Rapid Fabrication by Digital Light Processing 3D Printing of a SlipChip with Movable Ports for Local Delivery to Ex Vivo Organ Cultures. MICROMACHINES 2021; 12:993. [PMID: 34442615 PMCID: PMC8399530 DOI: 10.3390/mi12080993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/14/2021] [Accepted: 08/18/2021] [Indexed: 12/28/2022]
Abstract
SlipChips are two-part microfluidic devices that can be reconfigured to change fluidic pathways for a wide range of functions, including tissue stimulation. Currently, fabrication of these devices at the prototype stage requires a skilled microfluidic technician, e.g., for wet etching or alignment steps. In most cases, SlipChip functionality requires an optically clear, smooth, and flat surface that is fluorophilic and hydrophobic. Here, we tested digital light processing (DLP) 3D printing, which is rapid, reproducible, and easily shared, as a solution for fabrication of SlipChips at the prototype stage. As a case study, we sought to fabricate a SlipChip intended for local delivery to live tissue slices through a movable microfluidic port. The device was comprised of two multi-layer components: an enclosed channel with a delivery port and a culture chamber for tissue slices with a permeable support. Once the design was optimized, we demonstrated its function by locally delivering a chemical probe to slices of hydrogel and to living tissue with up to 120 µm spatial resolution. By establishing the design principles for 3D printing of SlipChip devices, this work will enhance the ability to rapidly prototype such devices at mid-scale levels of production.
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Affiliation(s)
- Megan A Catterton
- Department of Chemistry, University of Virginia College of Arts and Science, Charlottesville, VA 22904, USA;
| | - Alexander G Ball
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22903, USA;
| | - Rebecca R Pompano
- Department of Chemistry, University of Virginia College of Arts and Science, Charlottesville, VA 22904, USA;
- Carter Immunology Center and UVA Cancer Center, University of Virginia, Charlottesville, VA 22903, USA
- Department of Biomedical Engineering, University of Virginia School of Engineering and Applied Sciences, Charlottesville, VA 22904-4259, USA
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3
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Belanger MC, Anbaei P, Dunn AF, Kinman AW, Pompano RR. Spatially Resolved Analytical Chemistry in Intact, Living Tissues. Anal Chem 2020; 92:15255-15262. [PMID: 33201681 PMCID: PMC7864589 DOI: 10.1021/acs.analchem.0c03625] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tissues are an exciting frontier for bioanalytical chemistry, one in which spatial distribution is just as important as total content. Intact tissue preserves the native cellular and molecular organization and the cell-cell contacts found in vivo. Live tissue, in particular, offers the potential to analyze dynamic events in a spatially resolved manner, leading to fundamental biological insights and translational discoveries. In this Perspective, we provide a tutorial on the four fundamental challenges for the bioanalytical chemist working in living tissue samples as well as best practices for mitigating them. The challenges include (i) the complexity of the sample matrix, which contributes myriad interfering species and causes nonspecific binding of reagents; (ii) hindered delivery and mixing; (iii) the need to maintain physiological conditions; and (iv) tissue reactivity. This framework is relevant to a variety of methods for spatially resolved chemical analysis, including optical imaging, inserted sensors and probes such as electrodes, and surface analyses such as sensing arrays. The discussion focuses primarily on ex vivo tissues, though many considerations are relevant in vivo as well. Our goal is to convey the exciting potential of analytical chemistry to contribute to understanding the functions of live, intact tissues.
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Affiliation(s)
- Maura C. Belanger
- Department of Chemistry, University of Virginia, PO BOX 400319, Charlottesville, VA 22904
| | - Parastoo Anbaei
- Department of Chemistry, University of Virginia, PO BOX 400319, Charlottesville, VA 22904
| | - Austin F. Dunn
- Department of Chemistry, University of Virginia, PO BOX 400319, Charlottesville, VA 22904
| | - Andrew W.L. Kinman
- Department of Chemistry, University of Virginia, PO BOX 400319, Charlottesville, VA 22904
| | - Rebecca R. Pompano
- Department of Chemistry, University of Virginia, PO BOX 400319, Charlottesville, VA 22904
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4
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de Hoyos-Vega JM, Gonzalez-Suarez AM, Garcia-Cordero JL. A versatile microfluidic device for multiple ex vivo/in vitro tissue assays unrestrained from tissue topography. MICROSYSTEMS & NANOENGINEERING 2020; 6:40. [PMID: 34567653 PMCID: PMC8433291 DOI: 10.1038/s41378-020-0156-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 03/04/2020] [Accepted: 03/12/2020] [Indexed: 05/28/2023]
Abstract
Precision-cut tissue slices are an important in vitro system to study organ function because they preserve most of the native cellular microenvironments of organs, including complex intercellular connections. However, during sample manipulation or slicing, some of the natural surface topology and structure of these tissues is lost or damaged. Here, we introduce a microfluidic platform to perform multiple assays on the surface of a tissue section, unhindered by surface topography. The device consists of a valve on one side and eight open microchannels located on the opposite side, with the tissue section sandwiched between these two structures. When the valve is actuated, eight independent microfluidic channels are formed over a tissue section. This strategy prevents cross-contamination when performing assays and enables parallelization. Using irregular tissues such as an aorta, we conducted multiple in vitro and ex vivo assays on tissue sections, including short-term culturing, a drug toxicity assay, a fluorescence immunohistochemistry staining assay, and an immune cell assay, in which we observed the interaction of neutrophils with lipopolysaccharide (LPS)-stimulated endothelium. Our microfluidic platform can be employed in other disciplines, such as tissue physiology and pathophysiology, morphogenesis, drug toxicity and efficiency, metabolism studies, and diagnostics, enabling the conduction of several assays with a single biopsy sample.
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Affiliation(s)
- Jose M. de Hoyos-Vega
- Unidad Monterrey, Centro de Investigación y de Estudios Avanzados del IPN, Via del conocimiento 201, Parque PIIT, Apodaca, NL 66628 Mexico
| | - Alan M. Gonzalez-Suarez
- Unidad Monterrey, Centro de Investigación y de Estudios Avanzados del IPN, Via del conocimiento 201, Parque PIIT, Apodaca, NL 66628 Mexico
| | - Jose L. Garcia-Cordero
- Unidad Monterrey, Centro de Investigación y de Estudios Avanzados del IPN, Via del conocimiento 201, Parque PIIT, Apodaca, NL 66628 Mexico
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5
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Horowitz LF, Rodriguez AD, Ray T, Folch A. Microfluidics for interrogating live intact tissues. MICROSYSTEMS & NANOENGINEERING 2020; 6:69. [PMID: 32879734 PMCID: PMC7443437 DOI: 10.1038/s41378-020-0164-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/10/2020] [Accepted: 03/12/2020] [Indexed: 05/08/2023]
Abstract
The intricate microarchitecture of tissues - the "tissue microenvironment" - is a strong determinant of tissue function. Microfluidics offers an invaluable tool to precisely stimulate, manipulate, and analyze the tissue microenvironment in live tissues and engineer mass transport around and into small tissue volumes. Such control is critical in clinical studies, especially where tissue samples are scarce, in analytical sensors, where testing smaller amounts of analytes results in faster, more portable sensors, and in biological experiments, where accurate control of the cellular microenvironment is needed. Microfluidics also provides inexpensive multiplexing strategies to address the pressing need to test large quantities of drugs and reagents on a single biopsy specimen, increasing testing accuracy, relevance, and speed while reducing overall diagnostic cost. Here, we review the use of microfluidics to study the physiology and pathophysiology of intact live tissues at sub-millimeter scales. We categorize uses as either in vitro studies - where a piece of an organism must be excised and introduced into the microfluidic device - or in vivo studies - where whole organisms are small enough to be introduced into microchannels or where a microfluidic device is interfaced with a live tissue surface (e.g. the skin or inside an internal organ or tumor) that forms part of an animal larger than the device. These microfluidic systems promise to deliver functional measurements obtained directly on intact tissue - such as the response of tissue to drugs or the analysis of tissue secretions - that cannot be obtained otherwise.
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Affiliation(s)
- Lisa F. Horowitz
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
| | - Adán D. Rodriguez
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
| | - Tyler Ray
- Department of Mechanical Engineering, University of Hawaiʻi at Mānoa, Honolulu, HI 96822 USA
| | - Albert Folch
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
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6
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Shim S, Belanger MC, Harris AR, Munson JM, Pompano RR. Two-way communication between ex vivo tissues on a microfluidic chip: application to tumor-lymph node interaction. LAB ON A CHIP 2019; 19:1013-1026. [PMID: 30742147 PMCID: PMC6416076 DOI: 10.1039/c8lc00957k] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Experimentally accessible tools to replicate the complex biological events of in vivo organs offer the potential to reveal mechanisms of disease and potential routes to therapy. In particular, models of inter-organ communication are emerging as the next essential step towards creating a body-on-a-chip, and may be particularly useful for poorly understood processes such as tumor immunity. In this paper, we report the first multi-compartment microfluidic chip that continuously recirculates a small volume of media through two ex vivo tissue samples to support inter-organ cross-talk via secreted factors. To test on-chip communication, protein release and capture were quantified using well-defined artificial tissue samples and model proteins. Proteins released by one sample were transferred to the downstream reservoir and detectable in the downstream sample. Next, the chip was applied to model the communication between a tumor and a lymph node, to test whether on-chip dual-organ culture could recreate key features of tumor-induced immune suppression. Slices of murine lymph node were co-cultured with tumor or healthy tissue on-chip with recirculating media, then tested for their ability to respond to T cell stimulation. Interestingly, lymph node slices co-cultured with tumor slices appeared more immunosuppressed than those co-cultured with healthy tissue, suggesting that the chip may successfully model some features of tumor-immune interaction. In conclusion, this new microfluidic system provides on-chip co-culture of pairs of tissue slices under continuous recirculating flow, and has the potential to model complex inter-organ communication ex vivo with full experimental accessibility of the tissues and their media.
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Affiliation(s)
- Sangjo Shim
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA.
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7
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Liu C, Gomez FA, Miao Y, Cui P, Lee W. A colorimetric assay system for dopamine using microfluidic paper-based analytical devices. Talanta 2018; 194:171-176. [PMID: 30609518 DOI: 10.1016/j.talanta.2018.10.039] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 10/09/2018] [Accepted: 10/10/2018] [Indexed: 12/20/2022]
Abstract
We report the colorimetric detection of dopamine (DA) on microfluidic paper-based analytical devices (μPADs) using an oxidation-reduction method. Here, dopamine reacts with ferric chloride forming reduced Fe2+ that subsequently reacts with phenanthroline to form the red tris(1,10-phenanthroline)iron(II) complex. The devices were fabricated by wax printing and changes in color intensity were recorded using a common cell phone. Subsequent analysis using Photoshop software, yielded a limit of detection (LOD) for DA of 0.37 μmol/L with a linear range of 0.527-4.75 μmol/L and relative standard deviation of 0.11% (inter-day) and 0.15% (intra-day) for n = 15 paper chips. The effects of detection conditions have been investigated and are discussed. Cow serum samples and human blood serum and plasma samples were detected. The work, herein, demonstrates the potential of this method as a low cost and rapid colorimetric technique to detect DA in real samples.
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Affiliation(s)
- Chunye Liu
- School of Pharmacy, Xi'an Medical University, Xi'an 710021, China.
| | - Frank A Gomez
- Department of Chemistry and Biochemistry, California State University, Los Angeles, CA, USA
| | - Yanqing Miao
- School of Pharmacy, Xi'an Medical University, Xi'an 710021, China
| | - Ping Cui
- School of Pharmacy, Xi'an Medical University, Xi'an 710021, China
| | - Wilson Lee
- Department of Chemistry and Biochemistry, California State University, Los Angeles, CA, USA
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8
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Catterton MA, Dunn AF, Pompano RR. User-defined local stimulation of live tissue through a movable microfluidic port. LAB ON A CHIP 2018; 18:2003-2012. [PMID: 29904762 PMCID: PMC6039252 DOI: 10.1039/c8lc00204e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Many in vivo tissue responses begin locally, yet most in vitro stimuli are delivered globally. Microfluidics has a unique ability to provide focal stimulation to tissue samples with precise control over fluid location, flow rate, and composition. However, previous devices utilizing fixed ports beneath the tissue required manual alignment of the tissue over the ports, increasing the risk of mechanical damage. Here we present a novel microfluidic device that allows the user to define the location of fluid delivery to a living tissue slice without manipulating the tissue itself. The device utilized a two-component SlipChip design to create a mobile port beneath the tissue slice. A culture chamber perforated by an array of ports housed a tissue slice and was separated by a layer of fluorocarbon oil from a single delivery port, fed by a microfluidic channel in the movable layer below. We derived and validated a physical model, based on interfacial tension and flow resistance, to predict the conditions under which fluid delivery occurred without leakage into the gap between layers. Aqueous solution was delivered reproducibly to samples of tissue and gel, and the width of the delivery region was controlled primarily by convection. Tissue slice viability was not affected by stimulation on the device. As a proof-of-principle, we showed that live slices of lymph node tissue could be sequentially targeted for precise stimulation. In the future this device may serve as a platform to study the effects of fluid flow in tissues and to perform local drug screening.
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Affiliation(s)
- Megan A Catterton
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA.
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9
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Ross AE, Pompano RR. Diffusion of cytokines in live lymph node tissue using microfluidic integrated optical imaging. Anal Chim Acta 2017; 1000:205-213. [PMID: 29289312 DOI: 10.1016/j.aca.2017.11.048] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 11/15/2017] [Accepted: 11/17/2017] [Indexed: 12/21/2022]
Abstract
Communication and drug efficacy in the immune system rely heavily on diffusion of proteins such as cytokines through the tissue matrix. Available methods to analyze diffusion in tissue require microinjection or saturating the tissue in protein, which may alter local transport properties due to damage or rapid cellular responses. Here, we developed a novel, user-friendly method - Microfluidic Integrated Optical Imaging (micro-IOI) - to quantify the effective diffusion coefficient of bioactive proteins in live tissue samples ex vivo. A microfluidic platform was used to deliver picograms of fluorescently labelled cytokines to microscale regions within slices of murine lymph node, and diffusion was monitored by widefield fluorescence microscopy. Micro-IOI was validated against theory and existing methods. Free diffusion coefficients were within 8% and 24% of Stokes-Einstein predictions for dextrans and cytokines, respectively. Furthermore, diffusion coefficients for dextrans and proteins in a model matrix were within 1.5-fold of reported results from fluorescence recovery after photobleaching (FRAP). We used micro-IOI to quantify the effective diffusion of three cytokines from different structural classes and two different expression systems - tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and interleukin-2 (IL-2), from human and mouse - through live lymph node tissue. This is the first method to directly measure cytokine transport in live tissue slices, and in the future, it should promote a deeper understanding of the dynamics of cell-cell communication and enable targeted immunotherapy design.
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Affiliation(s)
- A E Ross
- Department of Chemistry, University of Virginia, McCormick Rd., PO Box 400319, Charlottesville, VA 22904, USA
| | - R R Pompano
- Department of Chemistry, University of Virginia, McCormick Rd., PO Box 400319, Charlottesville, VA 22904, USA.
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10
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Watson DE, Hunziker R, Wikswo JP. Fitting tissue chips and microphysiological systems into the grand scheme of medicine, biology, pharmacology, and toxicology. Exp Biol Med (Maywood) 2017; 242:1559-1572. [PMID: 29065799 DOI: 10.1177/1535370217732765] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Microphysiological systems (MPS), which include engineered organoids (EOs), single organ/tissue chips (TCs), and multiple organs interconnected to create miniature in vitro models of human physiological systems, are rapidly becoming effective tools for drug development and the mechanistic understanding of tissue physiology and pathophysiology. The second MPS thematic issue of Experimental Biology and Medicine comprises 15 articles by scientists and engineers from the National Institutes of Health, the IQ Consortium, the Food and Drug Administration, and Environmental Protection Agency, an MPS company, and academia. Topics include the progress, challenges, and future of organs-on-chips, dissemination of TCs into Pharma, children's health protection, liver zonation, liver chips and their coupling to interconnected systems, gastrointestinal MPS, maturation of immature cardiomyocytes in a heart-on-a-chip, coculture of multiple cell types in a human skin construct, use of synthetic hydrogels to create EOs that form neural tissue models, the blood-brain barrier-on-a-chip, MPS models of coupled female reproductive organs, coupling MPS devices to create a body-on-a-chip, and the use of a microformulator to recapitulate endocrine circadian rhythms. While MPS hardware has been relatively stable since the last MPS thematic issue, there have been significant advances in cell sourcing, with increased reliance on human-induced pluripotent stem cells, and in characterization of the genetic and functional cell state in MPS bioreactors. There is growing appreciation of the need to minimize perfusate-to-cell-volume ratios and respect physiological scaling of coupled TCs. Questions asked by drug developers are followed by an analysis of the potential value, costs, and needs of Pharma. Of highest value and lowest switching costs may be the development of MPS disease models to aid in the discovery of disease mechanisms; novel compounds including probes, leads, and clinical candidates; and mechanism of action of drug candidates. Impact statement Microphysiological systems (MPS), which include engineered organoids and both individual and coupled organs-on-chips and tissue chips, are a rapidly growing topic of research that addresses the known limitations of conventional cellular monoculture on flat plastic - a well-perfected set of techniques that produces reliable, statistically significant results that may not adequately represent human biology and disease. As reviewed in this article and the others in this thematic issue, MPS research has made notable progress in the past three years in both cell sourcing and characterization. As the field matures, currently identified challenges are being addressed, and new ones are being recognized. Building upon investments by the Defense Advanced Research Projects Agency, National Institutes of Health, Food and Drug Administration, Defense Threat Reduction Agency, and Environmental Protection Agency of more than $200 million since 2012 and sizable corporate spending, academic and commercial players in the MPS community are demonstrating their ability to meet the translational challenges required to apply MPS technologies to accelerate drug development and advance toxicology.
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Affiliation(s)
| | - Rosemarie Hunziker
- 2 National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - John P Wikswo
- 3 Departments of Biomedical Engineering, Molecular Physiology & Biophysics, and Physics & Astronomy, Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, TN 37235-1807, USA
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11
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Pompano RR, Chiang AH, Kastrup CJ, Ismagilov RF. Conceptual and Experimental Tools to Understand Spatial Effects and Transport Phenomena in Nonlinear Biochemical Networks Illustrated with Patchy Switching. Annu Rev Biochem 2017; 86:333-356. [PMID: 28654324 PMCID: PMC10852032 DOI: 10.1146/annurev-biochem-060815-014207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many biochemical systems are spatially heterogeneous and exhibit nonlinear behaviors, such as state switching in response to small changes in the local concentration of diffusible molecules. Systems as varied as blood clotting, intracellular calcium signaling, and tissue inflammation are all heavily influenced by the balance of rates of reaction and mass transport phenomena including flow and diffusion. Transport of signaling molecules is also affected by geometry and chemoselective confinement via matrix binding. In this review, we use a phenomenon referred to as patchy switching to illustrate the interplay of nonlinearities, transport phenomena, and spatial effects. Patchy switching describes a change in the state of a network when the local concentration of a diffusible molecule surpasses a critical threshold. Using patchy switching as an example, we describe conceptual tools from nonlinear dynamics and chemical engineering that make testable predictions and provide a unifying description of the myriad possible experimental observations. We describe experimental microfluidic and biochemical tools emerging to test conceptual predictions by controlling transport phenomena and spatial distribution of diffusible signals, and we highlight the unmet need for in vivo tools.
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Affiliation(s)
- Rebecca R Pompano
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904;
| | - Andrew H Chiang
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637;
| | - Christian J Kastrup
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada;
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125;
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12
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Brimmo AT, Qasaimeh MA. Microfluidic Probes and Quadrupoles: A new era of open microfluidics. IEEE NANOTECHNOLOGY MAGAZINE 2017. [DOI: 10.1109/mnano.2016.2633678] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Ross AE, Belanger MC, Woodroof JF, Pompano RR. Spatially resolved microfluidic stimulation of lymphoid tissue ex vivo. Analyst 2017; 142:649-659. [PMID: 27900374 PMCID: PMC7863610 DOI: 10.1039/c6an02042a] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The lymph node is a structurally complex organ of the immune system, whose dynamic cellular arrangements are thought to control much of human health. Currently, no methods exist to precisely stimulate substructures within the lymph node or analyze local stimulus-response behaviors, making it difficult to rationally design therapies for inflammatory disease. Here we describe a novel integration of live lymph node slices with a microfluidic system for local stimulation. Slices maintained the cellular organization of the lymph node while making its core experimentally accessible. The 3-layer polydimethylsiloxane device consisted of a perfusion chamber stacked atop stimulation ports fed by underlying microfluidic channels. Fluorescent dextrans similar in size to common proteins, 40 and 70 kDa, were delivered to live lymph node slices with 284 ± 9 μm and 202 ± 15 μm spatial resolution, respectively, after 5 s, which is sufficient to target functional zones of the lymph node. The spread and quantity of stimulation were controlled by varying the flow rates of delivery; these were predictable using a computational model of isotropic diffusion and convection through the tissue. Delivery to two separate regions simultaneously was demonstrated, to mimic complex intercellular signaling. Delivery of a model therapeutic, glucose-conjugated albumin, to specific regions of the lymph node indicated that retention of the drug was greater in the B-cell zone than in the T-cell zone. Together, this work provides a novel platform, the lymph node slice-on-a-chip, to target and study local events in the lymph node and to inform the development of new immunotherapeutics.
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Affiliation(s)
- Ashley E Ross
- University of Virginia, Dept. of Chemistry, PO Box 400319, McCormick Rd, Charlottesville, VA 22904, USA.
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14
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Liu C, Gomez FA. A microfluidic paper‐based device to assess acetylcholinesterase activity. Electrophoresis 2017; 38:1002-1006. [DOI: 10.1002/elps.201600206] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 09/29/2016] [Accepted: 12/11/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Chunye Liu
- Department of Chemistry and Biochemistry California State University Los Angeles CA USA
- School of Pharmacy Xi'an Medical University Xi'an P. R. China
| | - Frank A. Gomez
- Department of Chemistry and Biochemistry California State University Los Angeles CA USA
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15
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Dorris DM, Hauser CA, Minnehan CE, Meitzen J. An aerator for brain slice experiments in individual cell culture plate wells. J Neurosci Methods 2014; 238:1-10. [PMID: 25256645 DOI: 10.1016/j.jneumeth.2014.09.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Ex vivo acute living brain slices are a broadly employed and powerful experimental preparation. Most new technology regarding this tissue has involved the chamber used when performing electrophysiological experiments. Alternatively we instead focus on the creation of a simple, versatile aerator designed to allow maintenance and manipulation of acute brain slices and potentially other tissue in a multi-well cell culture plate. NEW METHOD Here we present an easily manufactured aerator designed to fit into a 24-well cell culture plate. It features a nylon mesh and a single microhole to enable gas delivery without compromising tissue stability. The aerator is designed to be individually controlled, allowing both high throughput and single well experiments. RESULTS The aerator was validated by testing material leach, dissolved oxygen delivery, brain slice viability and neuronal electrophysiology. Example experiments are also presented, including a test of whether β1-adrenergic receptor activation regulates gene expression in ex vivo dorsal striatum using qPCR. COMPARISON WITH EXISTING METHODS Key differences include enhanced control over gas delivery to individual wells containing brain slices, decreased necessary volume, a sample restraint to reduce movement artifacts, the potential to be sterilized, the avoidance of materials that absorb water and small biological molecules, minimal production costs, and increased experimental throughput. CONCLUSION This new aerator is of high utility and will be useful for experiments involving brain slices and other potentially tissue samples in 24-well cell culture plates.
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Affiliation(s)
- David M Dorris
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Caitlin A Hauser
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Caitlin E Minnehan
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - John Meitzen
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA; W.M. Keck Center for Behavioral Biology, Center for Human Health and the Environment, and Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, NC, USA.
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16
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Sun M, Kaplan SV, Gehringer RC, Limbocker RA, Johnson MA. Localized drug application and sub-second voltammetric dopamine release measurements in a brain slice perfusion device. Anal Chem 2014; 86:4151-6. [PMID: 24734992 PMCID: PMC4018083 DOI: 10.1021/ac5008927] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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The
use of fast scan cyclic voltammetry (FSCV) to measure the release
and uptake of dopamine (DA) as well as other biogenic molecules in
viable brain tissue slices has gained popularity over the last 2 decades.
Brain slices have the advantage of maintaining the functional three-dimensional
architecture of the neuronal network while also allowing researchers
to obtain multiple sets of measurements from a single animal. In this
work, we describe a simple, easy-to-fabricate perfusion device designed
to focally deliver pharmacological agents to brain slices. The device
incorporates a microfluidic channel that runs under the perfusion
bath and a microcapillary that supplies fluid from this channel up
to the slice. We measured electrically evoked DA release in brain
slices before and after the administration of two dopaminergic stimulants,
cocaine and GBR-12909. Measurements were collected at two locations,
one directly over and the other 500 μm away from the capillary
opening. Using this approach, the controlled delivery of drugs to
a confined region of the brain slice and the application of this chamber
to FSCV measurements, were demonstrated. Moreover, the consumption
of drugs was reduced to tens of microliters, which is thousands of
times less than traditional perfusion methods. We expect that this
simply fabricated device will be useful in providing spatially resolved
delivery of drugs with minimum consumption for voltammetric and electrophysiological
studies of a variety of biological tissues both in vitro and ex vivo.
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Affiliation(s)
- Meng Sun
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas , Lawrence, Kansas 66045 United States
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17
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Croushore CA, Sweedler JV. Microfluidic systems for studying neurotransmitters and neurotransmission. LAB ON A CHIP 2013; 13:1666-76. [PMID: 23474943 PMCID: PMC3632338 DOI: 10.1039/c3lc41334a] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Neurotransmitters and neuromodulators are molecules within the nervous system that play key roles in cell-to-cell communication. Upon stimulation, neurons release these signaling molecules, which then act at local or distant locations to elicit a physiological response. Ranging from small molecules, such as diatomic gases and amino acids, to larger peptides, these chemical messengers are involved in many functional processes including growth, reproduction, memory and behavior. Understanding signaling molecules and the conditions that govern their release in healthy or damaged networks promises to deliver insights into neural network formation and function. Microfluidic devices can provide optimal cell culture conditions, reduced volume systems, and precise control over the chemical and physical nature of the extracellular environment, making them well-suited for studying neurotransmission and other forms of cell-to-cell signaling. Here we review selected microfluidic approaches that are suitable for monitoring cell-to-cell signaling molecules. We highlight devices that improve in vivo sample collection as well as compartmentalized devices designed to isolate individual neurons or co-cultures in vitro, including a focus on systems used for studying neural injury and regeneration, and devices that allow selective chemical stimulations and the characterization of released molecules.
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Affiliation(s)
- Callie A. Croushore
- Department of Chemistry and the Beckman Institute for Advanced Science
and Technology, University of Illinois at Urbana-Champaign, Urbana IL 61801,
USA
| | - Jonathan V. Sweedler
- Department of Chemistry and the Beckman Institute for Advanced Science
and Technology, University of Illinois at Urbana-Champaign, Urbana IL 61801,
USA
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18
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Thomas MG, Covington JA, Wall MJ. A chamber for the perfusion of in vitro tissue with multiple solutions. J Neurophysiol 2013; 110:269-77. [PMID: 23576703 DOI: 10.1152/jn.01039.2012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
There are currently no practical systems that allow extended regions (>5 mm(2)) of a tissue slice in vitro to be exposed, in isolation, to changes in ionic conditions or to pharmacological manipulation. Previous work has only achieved this at the expense of access to the tissue for recording electrodes. Here, we present a chamber that allows a tissue slice to be maintained in multiple solutions, at physiological temperatures, and preserves the ability to record from the slice. We demonstrate the effectiveness of the tissue bath with respect to minimizing the mixing of the solutions, maintaining the viability of the tissue, and preserving the ability to record from the slice simultaneously.
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Affiliation(s)
- Matthew G Thomas
- School of Life Sciences, University of Warwick, Coventry, United Kingdom.
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19
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Scott A, Weir K, Easton C, Huynh W, Moody WJ, Folch A. A microfluidic microelectrode array for simultaneous electrophysiology, chemical stimulation, and imaging of brain slices. LAB ON A CHIP 2013; 13:527-35. [PMID: 23042571 PMCID: PMC3737778 DOI: 10.1039/c2lc40826k] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In order to understand information processing in neural circuits, it is necessary to detect both electrical and chemical signaling with high spatial and temporal resolution. Although the primary currency of neural information processing is electrical, many of the downstream effects of the electrical signals on the circuits that generate them are dependent on activity-dependent increases in intracellular calcium concentration. It is therefore of great utility to be able to record electrical signals in neural circuits at multiple sites, while at the same time detecting optical signals from reporters of intracellular calcium levels. We describe here a microfluidic multi-electrode array (MMEA) capable of high-resolution extracellular recording from brain slices that is optically compatible with calcium imaging at single cell resolution. We show the application of the MMEA device to record waves of spontaneous activity in developing cortical slices and to perform multi-site extracellular recordings during simultaneous calcium imaging of activity. The MMEA has the unique capability to simultaneously allow focal electrical and chemical stimuli at different locations of the surface of a brain slice.
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Affiliation(s)
- Adina Scott
- Department of Bioengineering, University of Washington, Seattle, Washington, 98195, USA
| | - Keiko Weir
- Department of Biology, University of Washington, Seattle, Washington, 98195, USA
| | - Curtis Easton
- Department of Biology, University of Washington, Seattle, Washington, 98195, USA
| | - Wilson Huynh
- Department of Bioengineering, University of Washington, Seattle, Washington, 98195, USA
| | - William J. Moody
- Department of Biology, University of Washington, Seattle, Washington, 98195, USA
| | - Albert Folch
- Department of Bioengineering, University of Washington, Seattle, Washington, 98195, USA
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20
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Ahrar S, Nguyen TV, Shi Y, Ikrar T, Xu X, Hui EE. Optical stimulation and imaging of functional brain circuitry in a segmented laminar flow chamber. LAB ON A CHIP 2013; 13:536-41. [PMID: 23044655 PMCID: PMC3554874 DOI: 10.1039/c2lc40689f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Microfluidic technology is emerging as a useful tool for the study of brain slices, offering precise delivery of chemical factors along with robust oxygen and nutrient transport. However, continued reliance upon electrode-based physiological recording poses inherent limitations in terms of physical access, as well as the number of sites that can be sampled simultaneously. In the present study, we combine a microfluidic laminar flow chamber with fast voltage-sensitive dye imaging and laser photostimulation via caged glutamate to map neural network activity across large cortical regions in living brain slices. We find that the closed microfluidic chamber results in greatly improved signal-to-noise performance for optical measurements of neural signaling. These optical tools are also leveraged to characterize laminar flow interfaces within the device, demonstrating a functional boundary width of less than 100 μm. Finally, we utilize this integrated platform to investigate the mechanism of signal propagation for spontaneous neural activity in the developing mouse hippocampus. Through the use of localized Ca(2+) depletion, we provide evidence for Ca(2+)-dependent synaptic transmission.
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Affiliation(s)
- Siavash Ahrar
- Department of Biomedical Engineering, University of California, Irvine, CA 92697-2715, United States. Fax: 01 949 824 1727; Tel: 01 949 824 1727
| | - Transon V. Nguyen
- Department of Biomedical Engineering, University of California, Irvine, CA 92697-2715, United States. Fax: 01 949 824 1727; Tel: 01 949 824 1727
| | - Yulin Shi
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697-1275, United States
| | - Taruna Ikrar
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697-1275, United States
| | - Xiangmin Xu
- Department of Biomedical Engineering, University of California, Irvine, CA 92697-2715, United States. Fax: 01 949 824 1727; Tel: 01 949 824 1727
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697-1275, United States
- To whom correspondence should be addressed
| | - Elliot E. Hui
- Department of Biomedical Engineering, University of California, Irvine, CA 92697-2715, United States. Fax: 01 949 824 1727; Tel: 01 949 824 1727
- To whom correspondence should be addressed
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21
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Sivagnanam V, Gijs MAM. Exploring Living Multicellular Organisms, Organs, and Tissues Using Microfluidic Systems. Chem Rev 2013; 113:3214-47. [DOI: 10.1021/cr200432q] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
| | - Martin A. M. Gijs
- Laboratory
of Microsystems, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne,
Switzerland
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22
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Qasaimeh MA, Ricoult SG, Juncker D. Microfluidic probes for use in life sciences and medicine. LAB ON A CHIP 2013; 13:40-50. [PMID: 23042577 DOI: 10.1039/c2lc40898h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Microfluidic probes (MFPs) combine the concepts of microfluidics and of scanning probes and constitute a contact-free and channel-free microfluidic system. Whereas classically the sample is introduced into the microfluidic device, with a MFP, the microfluidic stream is applied to the sample. MFPs use hydrodynamic flow confinement instead of walls to constrain a microfluidic stream between the MFP tip and a substrate. Because MFPs are free to move, they can be used to process large areas and samples in a selective manner. The development of MFP technology is recent and has numerous potential applications in several fields, most notably in the life sciences. In this review, we discuss the concept of MFPs and highlight their application in surface biopatterning, controlling the cellular microenvironments, local processing of tissue slices, and generating concentration gradients of biochemicals. We hope that this manuscript will serve as an interdisciplinary guide for both engineers as they further develop novel MFPs and applications and for life scientists who may identify novel uses of the MFP for their research.
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Affiliation(s)
- Mohammad A Qasaimeh
- Biomedical Engineering Department and Genome Quebec Innovation Centre, McGill University, Montreal, Canada
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23
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Mauleon G, Fall CP, Eddington DT. Precise spatial and temporal control of oxygen within in vitro brain slices via microfluidic gas channels. PLoS One 2012; 7:e43309. [PMID: 22905255 PMCID: PMC3419219 DOI: 10.1371/journal.pone.0043309] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 07/19/2012] [Indexed: 11/18/2022] Open
Abstract
The acute brain slice preparation is an excellent model for studying the details of how neurons and neuronal tissue respond to a variety of different physiological conditions. But open slice chambers ideal for electrophysiological and imaging access have not allowed the precise spatiotemporal control of oxygen in a way that might realistically model stroke conditions. To address this problem, we have developed a microfluidic add-on to a commercially available perfusion chamber that diffuses oxygen throughout a thin membrane and directly to the brain slice. A microchannel enables rapid and efficient control of oxygen and can be modified to allow different regions of the slice to experience different oxygen conditions. Using this novel device, we show that we can obtain a stable and homogeneous oxygen environment throughout the brain slice and rapidly alter the oxygen tension in a hippocampal slice. We also show that we can impose different oxygen tensions on different regions of the slice preparation and measure two independent responses, which is not easily obtainable with current techniques.
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Affiliation(s)
- Gerardo Mauleon
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Christopher P. Fall
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Computer Science, Georgetown University, Georgetown, Washington, D. C., United States of America
| | - David T. Eddington
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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24
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Huang Y, Williams JC, Johnson SM. Brain slice on a chip: opportunities and challenges of applying microfluidic technology to intact tissues. LAB ON A CHIP 2012; 12:2103-2117. [PMID: 22534786 DOI: 10.1039/c2lc21142d] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Isolated brain tissue, especially brain slices, are valuable experimental tools for studying neuronal function at the network, cellular, synaptic, and single channel levels. Neuroscientists have refined the methods for preserving brain slice viability and function and converged on principles that strongly resemble the approach taken by engineers in developing microfluidic devices. With respect to brain slices, microfluidic technology may 1) overcome the traditional limitations of conventional interface and submerged slice chambers and improve oxygen/nutrient penetration into slices, 2) provide better spatiotemporal control over solution flow/drug delivery to specific slice regions, and 3) permit successful integration with modern optical and electrophysiological techniques. In this review, we highlight the unique advantages of microfluidic devices for in vitro brain slice research, describe recent advances in the integration of microfluidic devices with optical and electrophysiological instrumentation, and discuss clinical applications of microfluidic technology as applied to brain slices and other non-neuronal tissues. We hope that this review will serve as an interdisciplinary guide for both neuroscientists studying brain tissue in vitro and engineers as they further develop microfluidic chamber technology for neuroscience research.
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Affiliation(s)
- Yu Huang
- University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, WI 53706, USA
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25
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Tang YT, Kim J, López-Valdés HE, Brennan KC, Ju YS. Development and characterization of a microfluidic chamber incorporating fluid ports with active suction for localized chemical stimulation of brain slices. LAB ON A CHIP 2011; 11:2247-54. [PMID: 21562669 PMCID: PMC5497172 DOI: 10.1039/c1lc20197b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We report a novel microfluidic chamber incorporating fluid ports with active suction to achieve localized chemical stimulation of brain slices. A two-level soft-lithography process is used to fabricate fluid ports with integrated injection and suction holes that are connected to underlying microchannels. Fluorescence imaging, particle tracking velocimetry, and cell staining are used to characterize flows around a fluid port with or without active suction to validate effective localization of injected chemicals. To demonstrate biological applicability of the chamber, we show an induction of cortical spreading depression (CSD) waves in mouse brain slices through controlled focal delivery of potassium chloride solution.
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Affiliation(s)
- Yujie Tanye Tang
- Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA, 90095-1597, USA
| | - Jichul Kim
- Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA, 90095-1597, USA
| | | | - K. C. Brennan
- Department of Neurology, University of California, Los Angeles, CA, 90095, USA
| | - Y. Sungtaek Ju
- Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA, 90095-1597, USA
- Biomedical Engineering Interdepartmental Program, University of California, Los Angeles, CA, 90095-1597, USA
- Y. Sungtaek Ju, ; Fax: +1-310-206-2302; Tel: +1-310-825-0985
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26
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Abstract
Understanding and optimizing fluid flows through in vitro microfluidic perfusion systems is essential in mimicking in vivo conditions for biological research. In a previous study a microfluidic brain slice device (μBSD) was developed for microscale electrophysiology investigations. The device consisted of a standard perfusion chamber bonded to a polydimethylsiloxane (PDMS) microchannel substrate. Our objective in this study is to characterize the flows through the μBSD by using multiphysics simulations of injections into a pourous matrix to identify optimal spacing of ports. Three-dimensional computational fluid dynamic (CFD) simulations are performed with CFD-ACE + software to model, simulate, and assess the transport of soluble factors through the perfusion bath, the microchannels, and a material that mimics the porosity, permeability and tortuosity of brain tissue. Additionally, experimental soluble factor transport through a brain slice is predicted by and compared to simulated fluid flow in a volume that represents a porous matrix material. The computational results are validated with fluorescent dye experiments.
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27
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Blake AJ, Rodgers FC, Bassuener A, Hippensteel JA, Pearce TM, Pearce TR, Zarnowska ED, Pearce RA, Williams JC. A microfluidic brain slice perfusion chamber for multisite recording using penetrating electrodes. J Neurosci Methods 2010; 189:5-13. [PMID: 20219536 PMCID: PMC3653971 DOI: 10.1016/j.jneumeth.2010.02.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 02/16/2010] [Accepted: 02/19/2010] [Indexed: 11/19/2022]
Abstract
To analyze the spatiotemporal dynamics of network activity in a brain tissue slice, it is useful to record simultaneously from multiple locations. When obtained from laminar structures such as the hippocampus or neocortex, multisite recordings also yield information about subcellular current distributions via current source density analysis. Multisite probes developed for in vivo recordings could serve these purposes in vitro, allowing recordings to be obtained from brain slices at sites deeper within the tissue than currently available surface recording methods permit. However, existing recording chambers do not allow for the insertion of lamina-spanning probes that enter through the edges of brain slices. Here, we present a novel brain slice recording chamber design that accomplishes this goal. The device provides a stable microfluidic perfusion environment in which tissue health is optimized by superfusing both surfaces of the slice. Multichannel electrodes can be inserted parallel to the surface of the slice, at any depth relative to the surface. Access is also provided from above for the insertion of additional recording or stimulating electrodes. We illustrate the utility of this recording configuration by measuring current sources and sinks during theta burst stimuli that lead to the induction of long-term potentiation in hippocampal slices.
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Affiliation(s)
- Alexander J. Blake
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53705
| | - Frank C. Rodgers
- Department of Anesthesiology, University of Wisconsin, Madison, WI 53711
| | - Anna Bassuener
- Department of Anesthesiology, University of Wisconsin, Madison, WI 53711
| | | | - Thomas M. Pearce
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53705
| | - Timothy R. Pearce
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53705
| | - Ewa D. Zarnowska
- Department of Anesthesiology, University of Wisconsin, Madison, WI 53711
| | - Robert A. Pearce
- Department of Anesthesiology, University of Wisconsin, Madison, WI 53711
| | - Justin C. Williams
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53705
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28
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Queval A, Ghattamaneni NR, Perrault CM, Gill R, Mirzaei M, McKinney RA, Juncker D. Chamber and microfluidic probe for microperfusion of organotypic brain slices. LAB ON A CHIP 2010; 10:326-34. [PMID: 20091004 DOI: 10.1039/b916669f] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Microfluidic systems are increasingly being used for the culture and study of dissociated cells because they require only minute amounts of materials while enabling drug screening and chemotaxis studies down to the single cell level. However, the culture of organized tissue, such as brain slices, has been more difficult to adapt to microfluidic devices. Here, we present a microfluidic system, comprising (i) a perfusion chamber for the culture of organotypic slices that is compatible with high resolution imaging on inverted microscopes, and (ii) a novel transparent microfluidic probe (MFP) for the localized microperfusion of the brain tissue. The MFP is made in poly(dimethylsiloxane), features six micrometre-scale apertures and can be assembled within a few hours in a standard laboratory. Each aperture can indiscriminately be used either for the injection or aspiration of solutions, giving rise to many possible combinations. The MFP was successfully used for the perfusion of a small number of cells in a brain slice with concurrent confocal fluorescence imaging of the perfused dye and sub-cellular structures within the tissue.
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Affiliation(s)
- Arthur Queval
- Biomedical Engineering Department, McGill University, 740, Dr. Penfield Ave, Montreal, Quebec H3A1A4, Canada
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