1
|
Hu J, Easley CJ. Development of a mix-and-read assay for human asprosin using antibody-oligonucleotide probes and thermofluorimetric analysis. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024. [PMID: 39171961 DOI: 10.1039/d3ay01175e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
Adipose tissue, or fat tissue, can now be classified as an endocrine organ as it responds to stimuli by secreting a range of hormones, termed adipokines, which regulate the functions of various other tissues and organs. Because novel adipokines continue to be discovered and characterized by researchers, there is an enduring need for the development of new analytical assays that target these hormones. Discovered recently, asprosin is an adipokine hormone secreted by white adipose tissue (WAT) during fasting which has been implicated for its important effects on the liver, skeletal muscle, hypothalamus, pancreas, and possibly other tissues. While standard immunoassays have been developed, the continued surge in research on asprosin's function would greatly benefit from an assay with homogeneous, mix-and-read workflow, and the nanomolar clinical range makes this goal more feasible. In this work, we developed such an assay for asprosin using our thermofluorimetric analysis (TFA) methods with antibody-oligonucleotide conjugate probes. The assay, achievable in less than one hour, was successfully validated by quantifying native levels of asprosin in human serum collected from fasting, nonfasting, type II diabetic, and obese donors.
Collapse
Affiliation(s)
- Juan Hu
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, USA.
| | | |
Collapse
|
2
|
Wang Y, Skinner EL, Roper MG. Comparison between capillary electrophoresis and fluorescence anisotropy competitive immunoassay for glucagon. Electrophoresis 2024. [PMID: 38984929 DOI: 10.1002/elps.202400080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 06/10/2024] [Accepted: 06/25/2024] [Indexed: 07/11/2024]
Abstract
Glucagon plays a crucial role in regulating glucose homeostasis; unfortunately, the mechanisms controlling its release are still unclear. Capillary electrophoresis (CE)- and fluorescence anisotropy (FA)-immunoassays (IA) have been used for online measurements of hormone secretion on microfluidic platforms, although their use in glucagon assays is less common. We set out to compare a glucagon-competitive IA using these two techniques. Theoretical calibration curves were generated for both CE- and FA-IA and results indicated that CE-IA provided higher sensitivity than FA-IA. These results were confirmed in an experiment where both assays showed limits of detection (LOD) of 30 nM, but the CE-IA had ∼300-fold larger sensitivity from 0 to 200 nM glucagon. However, in online experiments where reagents were mixed within the device, the sensitivity of the CE-IA was reduced ∼3-fold resulting in a higher LOD of 70 nM, whereas the FA-IA remained essentially unchanged. This lowered sensitivity in the online CE-IA was likely due to poor sampling by electroosmotic flow from the high salt solution necessary in online experiments, whereas pressure-based sampling used in FA-IA was not affected. We conclude that FA-IA, despite lowered sensitivity, is more suitable for online mixing scenarios due to the ability to use pressure-driven flow and other practical advantages such as the use of larger channels.
Collapse
Affiliation(s)
- Yao Wang
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA
| | - Emily L Skinner
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA
| | - Michael G Roper
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA
| |
Collapse
|
3
|
de Hoyos-Vega JM, Gonzalez-Suarez AM, Cedillo-Alcantar DF, Stybayeva G, Matveyenko A, Malhi H, Garcia-Cordero JL, Revzin A. Microfluidic 3D hepatic cultures integrated with a droplet-based bioanalysis unit. Biosens Bioelectron 2024; 248:115896. [PMID: 38176252 PMCID: PMC10916504 DOI: 10.1016/j.bios.2023.115896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 11/03/2023] [Accepted: 11/27/2023] [Indexed: 01/06/2024]
Abstract
A common challenge in microfluidic cell cultures has to do with analysis of cell function without replacing a significant fraction of the culture volume and disturbing local concentration gradients of signals. To address this challenge, we developed a microfluidic cell culture device with an integrated bioanalysis unit to enable on-chip analysis of picoliter volumes of cell-conditioned media. The culture module consisted of an array of 140 microwells with a diameter of 300 m which were made low-binding to promote organization of cells into 3D spheroids. The bioanalysis module contained a droplet generator unit, 15 micromechanical valves and reservoirs loaded with reagents. Each 0.8 nL droplet contained an aliquot of conditioned media mixed with assay reagents. The use of microvalves allowed us to load enzymatic assay and immunoassay into sequentially generated droplets for detection of glucose and albumin, respectively. As a biological application of the microfluidic device, we evaluated hormonal stimulation and glucose consumption of hepatic spheroids. To mimic physiological processes occurring during feeding and fasting, hepatic spheroids were exposed to pancreatic hormones, insulin or glucagon. The droplet-based bioanalysis module was used to measure uptake or release of glucose upon hormonal stimulation. In the future, we intend to use this microfluidic device to mimic and measure pathophysiological processes associated with hepatic insulin resistance and diabetes in the context of metabolic syndrome.
Collapse
Affiliation(s)
- Jose M de Hoyos-Vega
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | | | - Diana F Cedillo-Alcantar
- Laboratory of Microtechnologies Applied to Biomedicine, Centro de Investigación y de Estudios Avanzados (Cinvestav), Monterrey, NL, Mexico
| | - Gulnaz Stybayeva
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Aleksey Matveyenko
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Harmeet Malhi
- Division of Gastroenterology and Hepatology, Mayo Clinic, MN, USA
| | - Jose L Garcia-Cordero
- Laboratory of Microtechnologies Applied to Biomedicine, Centro de Investigación y de Estudios Avanzados (Cinvestav), Monterrey, NL, Mexico
| | - Alexander Revzin
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
| |
Collapse
|
4
|
Regeenes R, Rocheleau JV. Twenty years of islet-on-a-chip: microfluidic tools for dissecting islet metabolism and function. LAB ON A CHIP 2024; 24:1327-1350. [PMID: 38277011 DOI: 10.1039/d3lc00696d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
Pancreatic islets are metabolically active micron-sized tissues responsible for controlling blood glucose through the secretion of insulin and glucagon. A loss of functional islet mass results in type 1 and 2 diabetes. Islet-on-a-chip devices are powerful microfluidic tools used to trap and study living ex vivo human and murine pancreatic islets and potentially stem cell-derived islet organoids. Devices developed over the past twenty years offer the ability to treat islets with controlled and dynamic microenvironments to mimic in vivo conditions and facilitate diabetes research. In this review, we explore the various islet-on-a-chip devices used to immobilize islets, regulate the microenvironment, and dynamically detect islet metabolism and insulin secretion. We first describe and assess the various methods used to immobilize islets including chambers, dam-walls, and hydrodynamic traps. We subsequently describe the surrounding methods used to create glucose gradients, enhance the reaggregation of dispersed islets, and control the microenvironment of stem cell-derived islet organoids. We focus on the various methods used to measure insulin secretion including capillary electrophoresis, droplet microfluidics, off-chip ELISAs, and on-chip fluorescence anisotropy immunoassays. Additionally, we delve into the various multiparametric readouts (NAD(P)H, Ca2+-activity, and O2-consumption rate) achieved primarily by adopting a microscopy-compatible optical window into the devices. By critical assessment of these advancements, we aim to inspire the development of new devices by the microfluidics community and accelerate the adoption of islet-on-a-chip devices by the wider diabetes research and clinical communities.
Collapse
Affiliation(s)
- Romario Regeenes
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Jonathan V Rocheleau
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Departments of Medicine and Physiology, University of Toronto, ON, Canada
| |
Collapse
|
5
|
Ratto A, Honek JF. Oxocarbon Acids and their Derivatives in Biological and Medicinal Chemistry. Curr Med Chem 2024; 31:1172-1213. [PMID: 36915986 DOI: 10.2174/0929867330666230313141452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 03/15/2023]
Abstract
The biological and medicinal chemistry of the oxocarbon acids 2,3- dihydroxycycloprop-2-en-1-one (deltic acid), 3,4-dihydroxycyclobut-3-ene-1,2-dione (squaric acid), 4,5-dihydroxy-4-cyclopentene-1,2,3-trione (croconic acid), 5,6-dihydroxycyclohex- 5-ene-1,2,3,4-tetrone (rhodizonic acid) and their derivatives is reviewed and their key chemical properties and reactions are discussed. Applications of these compounds as potential bioisosteres in biological and medicinal chemistry are examined. Reviewed areas include cell imaging, bioconjugation reactions, antiviral, antibacterial, anticancer, enzyme inhibition, and receptor pharmacology.
Collapse
Affiliation(s)
- Amanda Ratto
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| | - John F Honek
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| |
Collapse
|
6
|
Wang Y, Regeenes R, Memon M, Rocheleau JV. Insulin C-peptide secretion on-a-chip to measure the dynamics of secretion and metabolism from individual islets. CELL REPORTS METHODS 2023; 3:100602. [PMID: 37820726 PMCID: PMC10626205 DOI: 10.1016/j.crmeth.2023.100602] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 08/16/2023] [Accepted: 09/15/2023] [Indexed: 10/13/2023]
Abstract
First-phase glucose-stimulated insulin secretion is mechanistically linked to type 2 diabetes, yet the underlying metabolism is difficult to discern due to significant islet-to-islet variability. Here, we miniaturize a fluorescence anisotropy immunoassay onto a microfluidic device to measure C-peptide secretion from individual islets as a surrogate for insulin (InsC-chip). This method measures secretion from up to four islets at a time with ∼7 s resolution while providing an optical window for real-time live-cell imaging. Using the InsC-chip, we reveal two glucose-dependent peaks of insulin secretion (i.e., a double peak) within the classically defined 1st phase (<10 min). By combining real-time secretion and live-cell imaging, we show islets transition from glycolytic to oxidative phosphorylation (OxPhos)-driven metabolism at the nadir of the peaks. Overall, these data validate the InsC-chip to measure glucose-stimulated insulin secretion while revealing new dynamics in secretion defined by a shift in glucose metabolism.
Collapse
Affiliation(s)
- Yufeng Wang
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Romario Regeenes
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Mahnoor Memon
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Jonathan V Rocheleau
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Departments of Medicine and Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
| |
Collapse
|
7
|
Adeoye DI, Wang Y, Davis JJ, Roper MG. Automated cellular stimulation with integrated pneumatic valves and fluidic capacitors. Analyst 2023; 148:1227-1234. [PMID: 36786685 PMCID: PMC10023383 DOI: 10.1039/d2an01985j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Microfluidic technologies have proven to be a reliable tool in profiling dynamic insulin secretion from islets of Langerhans. Most of these systems rely on external pressure sources to induce flow, leading to difficulties moving to more elaborate systems. To reduce complexity, a microfluidic system was developed that used a single vacuum source at the outlet to drive fluidic transport of immunoassay reagents and stimulation solutions throughout the device. A downside to this approach is the lack of flow control over the reagents delivered to the islet chamber. To address this challenge, 4-layer pneumatic valves were integrated into the perfusion lines to automate and control the delivery of stimulants; however, it was found that as the valves closed, spikes in the flow would lead to abnormal insulin secretion profiles. Fluidic capacitors were then incorporated after the valves and found to remove the spikes. The combination of the valves and capacitors resulted in automated collection of insulin secretion profiles from single murine islets that were similar to those previously reported in the literature. In the future, these integrated fluidic components may enable more complex channel designs to be used with a relatively simple flow control solution.
Collapse
Affiliation(s)
- Damilola I Adeoye
- Department of Chemistry & Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306, USA.
| | - Yao Wang
- Department of Chemistry & Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306, USA.
| | - Joshua J Davis
- Department of Chemistry & Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306, USA.
| | - Michael G Roper
- Department of Chemistry & Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306, USA. .,Program in Molecular Biophysics, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306, USA
| |
Collapse
|
8
|
Kniazev K, Guo T, Zhai C, Gamage RS, Ghonge S, Frantsuzov PA, Kuno M, Smith B. Single-molecule characterization of a bright and photostable deep-red fluorescent squaraine-figure-eight (SF8) dye. DYES AND PIGMENTS : AN INTERNATIONAL JOURNAL 2023; 210:111031. [PMID: 36643871 PMCID: PMC9835836 DOI: 10.1016/j.dyepig.2022.111031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Squaraine Figure Eight (SF8) dyes are a unique class of deep-red fluorescent dyes with self-threaded molecular architecture that provides structural rigidity while simultaneously encapsulating and protecting the emissive fluorochrome. Previous cell microscopy and bulk phase studies of SF8 dyes indicated order of magnitude enhancements in photostability over conventional pentamethine cyanine dyes such as Cy5. Studies conducted at the single molecule level now reveal that these ensemble level enhancements carry over to the single molecule level in terms of enhanced emission quantum yields, longer times to photobleaching, and enhanced total photon yields. When compared to Cy5, the SF8-based dye SF8(D4)2 possesses a three-fold larger single molecule emission quantum yield, exhibits order of magnitude longer average times before photobleaching, and exhibits twenty times larger photon yields. Additional features such as water solubility, fluorochrome encapsulation to protect it against nucleophilic attack, and selective biomarker targeting capability make SF8-based dyes promising candidates for biological labeling and microscopy applications and single molecule tracking.
Collapse
Affiliation(s)
- Kirill Kniazev
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Tianle Guo
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Canjia Zhai
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Rananjaya S. Gamage
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Sushrut Ghonge
- Department of Physics, University of Notre Dame, Notre Dame, IN 46556
| | - Pavel A. Frantsuzov
- Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Science, Institutskaya 3, Novosibirsk, 630090, Russia
| | - Masaru Kuno
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Department of Physics, University of Notre Dame, Notre Dame, IN 46556
| | - Bradley Smith
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| |
Collapse
|
9
|
Li W, Peng YF. Advances in microfluidic chips based on islet hormone-sensing techniques. World J Diabetes 2023; 14:17-25. [PMID: 36684385 PMCID: PMC9850799 DOI: 10.4239/wjd.v14.i1.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/11/2022] [Accepted: 12/07/2022] [Indexed: 01/10/2023] Open
Abstract
Diabetes mellitus is a global health problem resulting from islet dysfunction or insulin resistance. The mechanisms of islet dysfunction are still under investigation. Islet hormone secretion is the main function of islets, and serves an important role in the homeostasis of blood glucose. Elucidating the detailed mechanism of islet hormone secretome distortion can provide clues for the treatment of diabetes. Therefore, it is crucial to develop accurate, real-time, labor-saving, high-throughput, automated, and cost-effective techniques for the sensing of islet secretome. Microfluidic chips, an elegant platform that combines biology, engineering, computer science, and biomaterials, have attracted tremendous interest from scientists in the field of diabetes worldwide. These tiny devices are miniatures of traditional experimental systems with more advantages of time-saving, reagent-minimization, automation, high-throughput, and online detection. These features of microfluidic chips meet the demands of islet secretome analysis and a variety of chips have been designed in the past 20 years. In this review, we present a brief introduction of microfluidic chips, and three microfluidic chips-based islet hormone sensing techniques. We focus mainly on the theory of these techniques, and provide detailed examples based on these theories with the hope of providing some insights into the design of future chips or whole detection systems.
Collapse
Affiliation(s)
- Wei Li
- Department of Endocrinology, Suzhou Hospital of Anhui Medical University, Suzhou 234000, Anhui Province, China
| | - You-Fan Peng
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, Guangxi Zhuang Autonomous Region, China
| |
Collapse
|
10
|
Lapizco-Encinas BH, Zhang YV. Microfluidic systems in clinical diagnosis. Electrophoresis 2023; 44:217-245. [PMID: 35977346 DOI: 10.1002/elps.202200150] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 02/01/2023]
Abstract
The use of microfluidic devices is highly attractive in the field of biomedical and clinical assessments, as their portability and fast response time have become crucial in providing opportune therapeutic treatments to patients. The applications of microfluidics in clinical diagnosis and point-of-care devices are continuously growing. The present review article discusses three main fields where miniaturized devices are successfully employed in clinical applications. The quantification of ions, sugars, and small metabolites is examined considering the analysis of bodily fluids samples and the quantification of this type of analytes employing real-time wearable devices. The discussion covers the level of maturity that the devices have reached as well as cost-effectiveness. The analysis of proteins with clinical relevance is presented and organized by the function of the proteins. The last section covers devices that can perform single-cell metabolomic and proteomic assessments. Each section discusses several strategically selected recent reports on microfluidic devices successfully employed for clinical assessments, to provide the reader with a wide overview of the plethora of novel systems and microdevices developed in the last 5 years. In each section, the novel aspects and main contributions of each reviewed report are highlighted. Finally, the conclusions and future outlook section present a summary and speculate on the future direction of the field of miniaturized devices for clinical applications.
Collapse
Affiliation(s)
- Blanca H Lapizco-Encinas
- Microscale Bioseparations Laboratory and Biomedical Engineering Department, Rochester Institute of Technology, Rochester, New York, USA
| | - Yan Victoria Zhang
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, USA
| |
Collapse
|
11
|
Microfluidic Technology for Evaluating and Preserving Islet Function for Islet Transplant in Type 1 Diabetes. CURRENT TRANSPLANTATION REPORTS 2022. [DOI: 10.1007/s40472-022-00377-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
12
|
Increasing insulin measurement throughput by fluorescence anisotropy imaging immunoassays. Anal Chim Acta 2022; 1212:339942. [DOI: 10.1016/j.aca.2022.339942] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 01/25/2023]
|
13
|
Wu Jin P, Rousset N, Hierlemann A, Misun PM. A Microfluidic Hanging-Drop-Based Islet Perifusion System for Studying Glucose-Stimulated Insulin Secretion From Multiple Individual Pancreatic Islets. Front Bioeng Biotechnol 2021; 9:674431. [PMID: 34055765 PMCID: PMC8149801 DOI: 10.3389/fbioe.2021.674431] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/12/2021] [Indexed: 01/09/2023] Open
Abstract
Islet perifusion systems can be used to monitor the highly dynamic insulin release of pancreatic islets in glucose-stimulated insulin secretion (GSIS) assays. Here, we present a new generation of the microfluidic hanging-drop-based islet perifusion platform that was developed to study the alterations in insulin secretion dynamics from single pancreatic islet microtissues at high temporal resolution. The platform was completely redesigned to increase experimental throughput and to reduce operational complexity. The experimental throughput was increased fourfold by implementing a network of interconnected hanging drops, which allows for performing GSIS assays with four individual islet microtissues in parallel with a sampling interval of 30 s. We introduced a self-regulating drop-height mechanism that enables continuous flow and maintains a constant liquid volume in the chip, which enables simple and robust operation. Upon glucose stimulation, reproducible biphasic insulin release was simultaneously observed from all islets in the system. The measured insulin concentrations showed low sample-to-sample variation as a consequence of precise liquid handling with stable drop volumes, equal flow rates in the channels, and accurately controlled sampling volumes in all four drops. The presented device will be a valuable tool in islet and diabetes research for studying dynamic insulin secretion from individual pancreatic islets.
Collapse
Affiliation(s)
| | | | - Andreas Hierlemann
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Patrick M. Misun
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| |
Collapse
|
14
|
Yoshida R, Yasumatsu K, Ninomiya Y. The sweet taste receptor, glucose transporters, and the ATP-sensitive K+ (KATP) channel: sugar sensing for the regulation of energy homeostasis. CURRENT OPINION IN PHYSIOLOGY 2021. [DOI: 10.1016/j.cophys.2021.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|