1
|
Vehusheia SLK, Roman C, Braissant O, Arnoldini M, Hierold C. Enabling direct microcalorimetric measurement of metabolic activity and exothermic reactions onto microfluidic platforms via heat flux sensor integration. MICROSYSTEMS & NANOENGINEERING 2023; 9:56. [PMID: 37180454 PMCID: PMC10169645 DOI: 10.1038/s41378-023-00525-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 02/13/2023] [Indexed: 05/16/2023]
Abstract
All biological processes use or produce heat. Traditional microcalorimeters have been utilized to study the metabolic heat output of living organisms and heat production of exothermic chemical processes. Current advances in microfabrication have made possible the miniaturization of commercial microcalorimeters, resulting in a few studies on the metabolic activity of cells at the microscale in microfluidic chips. Here we present a new, versatile, and robust microcalorimetric differential design based on the integration of heat flux sensors on top of microfluidic channels. We show the design, modeling, calibration, and experimental verification of this system by utilizing Escherichia coli growth and the exothermic base catalyzed hydrolysis of methyl paraben as use cases. The system consists of a Polydimethylsiloxane based flow-through microfluidic chip with two 46 µl chambers and two integrated heat flux sensors. The differential compensation of thermal power measurements allows for the measurement of bacterial growth with a limit of detection of 1707 W/m3, corresponding to 0.021OD (2 ∙ 107 bacteria). We also extracted the thermal power of a single Escherichia coli of between 1.3 and 4.5 pW, comparable to values measured by industrial microcalorimeters. Our system opens the possibility for expanding already existing microfluidic systems, such as drug testing lab-on-chip platforms, with measurements of metabolic changes of cell populations in form of heat output, without modifying the analyte and minimal interference with the microfluidic channel itself.
Collapse
Affiliation(s)
- Signe L. K. Vehusheia
- Micro and Nanosystems, Department of Mechanical and Process Engineering, ETH Zurich, Tannenstrasse 3, 8092 Zurich, Switzerland
| | - Cosmin Roman
- Micro and Nanosystems, Department of Mechanical and Process Engineering, ETH Zurich, Tannenstrasse 3, 8092 Zurich, Switzerland
| | - Olivier Braissant
- Center of Biomechanics and Biocalorimetry, Department of Biomedical Engineering, University of Basel, Hegenheimermattweg 167C, 4123 Allschwil, Switzerland
| | - Markus Arnoldini
- Laboratory for Food Immunology, Department of Health Sciences and Technology, ETH Zurich, Otto-Stern-Weg 3, 8093 Zurich, Switzerland
| | - Christofer Hierold
- Micro and Nanosystems, Department of Mechanical and Process Engineering, ETH Zurich, Tannenstrasse 3, 8092 Zurich, Switzerland
| |
Collapse
|
2
|
Sultan AR, Tavakol M, Lemmens-den Toom NA, Croughs PD, Verkaik NJ, Verbon A, van Wamel WJB. Real time monitoring of Staphylococcus aureus biofilm sensitivity towards antibiotics with isothermal microcalorimetry. PLoS One 2022; 17:e0260272. [PMID: 35171906 PMCID: PMC8849495 DOI: 10.1371/journal.pone.0260272] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 11/05/2021] [Indexed: 12/14/2022] Open
Abstract
Biofilm-associated infections with Staphylococcus aureus are difficult to treat even after administration of antibiotics that according to the standard susceptibility assays are effective. Currently, the assays used in the clinical laboratories to determine the sensitivity of S. aureus towards antibiotics are not representing the behaviour of biofilm-associated S. aureus, since these assays are performed on planktonic bacteria. In research settings, microcalorimetry has been used for antibiotic susceptibility studies. Therefore, in this study we investigated if we can use isothermal microcalorimetry to monitor the response of biofilm towards antibiotic treatment in real-time. We developed a reproducible method to generate biofilm in an isothermal microcalorimeter setup. Using this system, the sensitivity of 5 methicillin-sensitive S. aureus (MSSA) and 5 methicillin-resistant S. aureus (MRSA) strains from different genetic lineages were determined towards: flucloxacillin, cefuroxime, cefotaxime, gentamicin, rifampicin, vancomycin, levofloxacin, clindamycin, erythromycin, linezolid, fusidic acid, co-trimoxazole, and doxycycline. In contrast to conventional assays, our calorimetry-based biofilm susceptibility assay showed that S. aureus biofilms, regardless MSSA or MRSA, can survive the exposure to the maximum serum concentration of all tested antibiotics. The only treatment with a single antibiotic showing a significant reduction in biofilm survival was rifampicin, yet in 20% of the strains, emerging antibiotic resistance was observed. Furthermore, the combination of rifampicin with flucloxacillin, vancomycin or levofloxacin was able to prevent S. aureus biofilm from becoming resistant to rifampicin. Isothermal microcalorimetry allows real-time monitoring of the sensitivity of S. aureus biofilms towards antibiotics in a fast and reliable way.
Collapse
Affiliation(s)
- Andi Rofian Sultan
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Microbiology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Mehri Tavakol
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Nicole A. Lemmens-den Toom
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Peter D. Croughs
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Nelianne J. Verkaik
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Annelies Verbon
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Willem J. B. van Wamel
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
- * E-mail:
| |
Collapse
|
3
|
Di Bonaventura G, Pompilio A. In Vitro Antimicrobial Susceptibility Testing of Biofilm-Growing Bacteria: Current and Emerging Methods. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1369:33-51. [PMID: 33963526 DOI: 10.1007/5584_2021_641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The antibiotic susceptibility of bacterial pathogens is typically determined based on planktonic cells, as recommended by several international guidelines. However, most of chronic infections - such as those established in wounds, cystic fibrosis lung, and onto indwelling devices - are associated to the formation of biofilms, communities of clustered bacteria attached onto a surface, abiotic or biotic, and embedded in an extracellular matrix produced by the bacteria and complexed with molecules from the host. Sessile microorganisms show significantly increased tolerance/resistance to antibiotics compared with planktonic counterparts. Consequently, antibiotic concentrations used in standard antimicrobial susceptibility tests, although effective against planktonic bacteria in vitro, are not predictive of the concentrations required to eradicate biofilm-related infections, thus leading to treatment failure, chronicization and removal of material in patients with indwelling medical devices.Meeting the need for the in vitro evaluation of biofilm susceptibility to antibiotics, here we reviewed several methods proposed in literature highlighting their advantages and limitations to guide scientists towards an appropriate choice.
Collapse
Affiliation(s)
- Giovanni Di Bonaventura
- Department of Medical, Oral and Biotechnological Sciences, and Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy. .,Laboratory of Clinical Microbiology, Chieti, Italy.
| | - Arianna Pompilio
- Department of Medical, Oral and Biotechnological Sciences, and Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Laboratory of Clinical Microbiology, Chieti, Italy
| |
Collapse
|
4
|
Wieland T, Assmann J, Bethe A, Fidelak C, Gmoser H, Janßen T, Kotthaus K, Lübke-Becker A, Wieler LH, Urban GA. A Real-Time Thermal Sensor System for Quantifying the Inhibitory Effect of Antimicrobial Peptides on Bacterial Adhesion and Biofilm Formation. SENSORS 2021; 21:s21082771. [PMID: 33919962 PMCID: PMC8070953 DOI: 10.3390/s21082771] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 01/15/2023]
Abstract
The increasing rate of antimicrobial resistance (AMR) in pathogenic bacteria is a global threat to human and veterinary medicine. Beyond antibiotics, antimicrobial peptides (AMPs) might be an alternative to inhibit the growth of bacteria, including AMR pathogens, on different surfaces. Biofilm formation, which starts out as bacterial adhesion, poses additional challenges for antibiotics targeting bacterial cells. The objective of this study was to establish a real-time method for the monitoring of the inhibition of (a) bacterial adhesion to a defined substrate and (b) biofilm formation by AMPs using an innovative thermal sensor. We provide evidence that the thermal sensor enables continuous monitoring of the effect of two potent AMPs, protamine and OH-CATH-30, on surface colonization of bovine mastitis-associated Escherichia (E.) coli and Staphylococcus (S.) aureus. The bacteria were grown under static conditions on the surface of the sensor membrane, on which temperature oscillations generated by a heater structure were detected by an amorphous germanium thermistor. Bacterial adhesion, which was confirmed by white light interferometry, caused a detectable amplitude change and phase shift. To our knowledge, the thermal measurement system has never been used to assess the effect of AMPs on bacterial adhesion in real time before. The system could be used to screen and evaluate bacterial adhesion inhibition of both known and novel AMPs.
Collapse
Affiliation(s)
- Tobias Wieland
- Department of Microsystems Engineering (IMTEK)—Laboratory of Sensors, University of Freiburg, 79110 Freiburg, Germany; (H.G.); (K.K.); (G.A.U.)
- Correspondence: ; Tel.: +49-761-203-7268
| | - Julia Assmann
- Institute of Microbiology and Epizootics, Freie Universität Berlin, 14163 Berlin, Germany; (J.A.); (A.B.); (A.L.-B.); (L.H.W.)
- Robert Koch Institute, ZBS4 Advanced Light and Electron Microscopy, 13353 Berlin, Germany
| | - Astrid Bethe
- Institute of Microbiology and Epizootics, Freie Universität Berlin, 14163 Berlin, Germany; (J.A.); (A.B.); (A.L.-B.); (L.H.W.)
| | | | - Helena Gmoser
- Department of Microsystems Engineering (IMTEK)—Laboratory of Sensors, University of Freiburg, 79110 Freiburg, Germany; (H.G.); (K.K.); (G.A.U.)
| | | | - Krishan Kotthaus
- Department of Microsystems Engineering (IMTEK)—Laboratory of Sensors, University of Freiburg, 79110 Freiburg, Germany; (H.G.); (K.K.); (G.A.U.)
| | - Antina Lübke-Becker
- Institute of Microbiology and Epizootics, Freie Universität Berlin, 14163 Berlin, Germany; (J.A.); (A.B.); (A.L.-B.); (L.H.W.)
| | - Lothar H. Wieler
- Institute of Microbiology and Epizootics, Freie Universität Berlin, 14163 Berlin, Germany; (J.A.); (A.B.); (A.L.-B.); (L.H.W.)
- Robert Koch Institute, 13353 Berlin, Germany
| | - Gerald A. Urban
- Department of Microsystems Engineering (IMTEK)—Laboratory of Sensors, University of Freiburg, 79110 Freiburg, Germany; (H.G.); (K.K.); (G.A.U.)
| |
Collapse
|
5
|
Liu Y, Lehnert T, Gijs MAM. Fast antimicrobial susceptibility testing on Escherichia coli by metabolic heat nanocalorimetry. LAB ON A CHIP 2020; 20:3144-3157. [PMID: 32677656 DOI: 10.1039/d0lc00579g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Fast spreading of antimicrobial resistance is now considered a major global health threat. New technologies are required, enabling rapid diagnostics of bacterial infection combined with fast antimicrobial susceptibility testing (AST) for evaluating the efficiency and dosage of antimicrobial compounds in vitro. This work presents an integrated chip-based isothermal nanocalorimetry platform for direct microbial metabolic heat measurements and evaluates its potential for fast AST. Direct detection of the bacteria-generated heat allows monitoring of metabolic activity and antimicrobial action at subinhibitory concentrations in real-time. The high heat sensitivity of the platform enables bacterial growth detection within only a few hours of incubation, whereas growth inhibition upon administration of antibiotics is revealed by a decrease or the absence of the heat signal. Antimicrobial stress results in lag phase extension and metabolic energy spilling. Oxygen consumption and optical density measurements provide a more holistic insight of the metabolic state and the evolution of bacterial biomass. As a proof-of-concept, a metabolic heat-based AST study on Escherichia coli as model organism with 3 clinically relevant antibiotics is performed and the minimum inhibitory concentrations are determined.
Collapse
Affiliation(s)
- Yang Liu
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - Thomas Lehnert
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - Martin A M Gijs
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| |
Collapse
|
6
|
Wang S, Sha X, Yu S, Zhao Y. Nanocalorimeters for biomolecular analysis and cell metabolism monitoring. BIOMICROFLUIDICS 2020; 14:011503. [PMID: 32038739 PMCID: PMC6994269 DOI: 10.1063/1.5134870] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 01/10/2020] [Indexed: 05/28/2023]
Abstract
Nanocalorimeters, or microfabricated calorimeters, provide a promising way to characterize the thermal process of biological processes, such as biomolecule interactions and cellular metabolic activities. They enabled miniaturized heat measurement onto a chip device with potential benefits including low sample consumption, low cost, portability, and high throughput. Over the past few decades, researchers have tried to improve nanocalorimeters' performance, in terms of sensitivity, accuracy, and detection resolution, by exploring different sensing methods, thermal insulation techniques, and liquid handling methods. The enhanced devices resulted in new applications in recent years, and here we have summarized the performance parameters and applications based on categories. Finally, we have listed the current technical difficulties in nanocalorimeter research and hope for future solutions to overcome them.
Collapse
Affiliation(s)
- Shuyu Wang
- Department of Control Engineering, Northeastern University, Qinhuangdao, Hebei 066001, People’s Republic of China
| | - Xiaopeng Sha
- Department of Control Engineering, Northeastern University, Qinhuangdao, Hebei 066001, People’s Republic of China
| | - Shifeng Yu
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA
| | - Yuliang Zhao
- Department of Control Engineering, Northeastern University, Qinhuangdao, Hebei 066001, People’s Republic of China
| |
Collapse
|
7
|
Temel F. Real-time and selective recognition of erythromycin by self-assembly of calix[4]arene on QCM sensor. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.111818] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
8
|
Response of Freshwater Biofilms to Antibiotic Florfenicol and Ofloxacin Stress: Role of Extracellular Polymeric Substances. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16050715. [PMID: 30818877 PMCID: PMC6427337 DOI: 10.3390/ijerph16050715] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 02/16/2019] [Accepted: 02/21/2019] [Indexed: 11/16/2022]
Abstract
Antibiotic residues have been detected in aquatic environments worldwide. Biofilms are one of the most successful life forms, and as a result are ubiquitous in natural waters. However, the response mechanism of freshwater biofilms to the stress of various antibiotic residues is still unclear. Here, the stress of veterinary antibiotic florfenicol (FF) and fluoroquinolone antibiotic ofloxacin (OFL) on freshwater biofilms were investigated by determining the changes in the key physicochemical and biological properties of the biofilms. The results showed that the chlorophyll a content in biofilms firstly decreased to 46–71% and then recovered to original content under the stress of FF and OFL with high, mid, and low concentrations. Meanwhile, the activities of antioxidant enzymes, including superoxide dismutase and catalase, increased between 1.3–6.7 times their initial values. FF was more toxic to the biofilms than OFL. The distribution coefficients of FF and OFL binding in extracellular polymeric substances (EPS)-free biofilms were 3.2 and 6.5 times higher than those in intact biofilms, respectively. It indicated that EPS could inhibit the FF and OFL accumulation in biofilm cells. The present study shows that the EPS matrix, as the house of freshwater biofilms, is the primary barrier that resists the stress from antibiotic residues.
Collapse
|
9
|
Pousti M, Zarabadi MP, Abbaszadeh Amirdehi M, Paquet-Mercier F, Greener J. Microfluidic bioanalytical flow cells for biofilm studies: a review. Analyst 2019; 144:68-86. [PMID: 30394455 DOI: 10.1039/c8an01526k] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Bacterial biofilms are among the oldest and most prevalent multicellular life forms on Earth and are increasingly relevant in research areas related to industrial fouling, medicine and biotechnology. The main hurdles to obtaining definitive experimental results include time-varying biofilm properties, structural and chemical heterogeneity, and especially their strong sensitivity to environmental cues. Therefore, in addition to judicious choice of measurement tools, a well-designed biofilm study requires strict control over experimental conditions, more so than most chemical studies. Due to excellent control over a host of physiochemical parameters, microfluidic flow cells have become indispensable in microbiological studies. Not surprisingly, the number of lab-on-chip studies focusing on biofilms and other microbiological systems with expanded analytical capabilities has expanded rapidly in the past decade. In this paper, we comprehensively review the current state of microfluidic bioanalytical research applied to bacterial biofilms and offer a perspective on new approaches that are expected to drive continued advances in this field.
Collapse
Affiliation(s)
- Mohammad Pousti
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec City, Québec G1 V 0A6, Canada
| | - Mir Pouyan Zarabadi
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec City, Québec G1 V 0A6, Canada
| | - Mehran Abbaszadeh Amirdehi
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec City, Québec G1 V 0A6, Canada
| | - François Paquet-Mercier
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec City, Québec G1 V 0A6, Canada
| | - Jesse Greener
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec City, Québec G1 V 0A6, Canada and CHU de Quebec Research Centre, Laval University, 10 rue de l'Espinay, Quebec City, (QC) G1L 3L5, Canada
| |
Collapse
|
10
|
Wang L, Li Y, Wang L, Zhu M, Zhu X, Qian C, Li W. Responses of biofilm microorganisms from moving bed biofilm reactor to antibiotics exposure: Protective role of extracellular polymeric substances. BIORESOURCE TECHNOLOGY 2018; 254:268-277. [PMID: 29413933 DOI: 10.1016/j.biortech.2018.01.063] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/12/2018] [Accepted: 01/14/2018] [Indexed: 06/08/2023]
Abstract
EPS can affect the migration of antibiotics in biofilm reactors, however the roles of biofilm EPS on the fate of antibiotics and the protective mechanisms to bacterial community remain unknown. We investigated the transport of three representative antibiotics in the biofilm suspension from a moving bed biofilm reactor. Spectral analysis suggested that proteins dominated the interactions between EPS and antibiotics. The adsorbed amounts of antibiotics onto EPS accounted for 14.5%, 88.2% and 13.1% of total concentration for sulfamethizole, tetracycline and norfloxacin, respectively at the biodegradation stage. The respiratory rates and representative enzymatic activities all experienced declines for biofilm without EPS in exposure to antibiotics. Gene sequencing results indicated that the bacterial community in biofilm without EPS was more vulnerable to antibiotics shocks. Our results demonstrated the protective roles of biofilm EPS in resisting antibiotics stresses, which provides important implications for understanding the bioremediation of antibiotics in biofilm systems.
Collapse
Affiliation(s)
- Longfei Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu 210098, China
| | - Yi Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu 210098, China.
| | - Li Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu 210098, China
| | - Mengjie Zhu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu 210098, China
| | - Xiaoxiao Zhu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, Jiangsu 210098, China
| | - Chen Qian
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, Anhui 230026, China
| | - Wenwei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, Anhui 230026, China
| |
Collapse
|
11
|
Wang S, Yu S, Siedler MS, Ihnat PM, Filoti DI, Lu M, Zuo L. Micro-differential scanning calorimeter for liquid biological samples. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:105005. [PMID: 27802741 DOI: 10.1063/1.4965443] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We developed an ultrasensitive micro-DSC (differential scanning calorimeter) for liquid protein sample characterization. This design integrated vanadium oxide thermistors and flexible polymer substrates with microfluidics chambers to achieve a high sensitivity (6 V/W), low thermal conductivity (0.7 mW/K), high power resolutions (40 nW), and well-defined liquid volume (1 μl) calorimeter sensor in a compact and cost-effective way. We further demonstrated the performance of the sensor with lysozyme unfolding. The measured transition temperature and enthalpy change were in accordance with the previous literature data. This micro-DSC could potentially raise the prospect of high-throughput biochemical measurement by parallel operation with miniaturized sample consumption.
Collapse
Affiliation(s)
- Shuyu Wang
- Department of Mechanical Engineering, Stony Brook University, Stony Brook, New York 11794, USA
| | - Shifeng Yu
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA
| | | | - Peter M Ihnat
- AbbVie Bioresearch Center, Worcester, Massachusetts 01605, USA
| | - Dana I Filoti
- AbbVie Bioresearch Center, Worcester, Massachusetts 01605, USA
| | - Ming Lu
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Lei Zuo
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA
| |
Collapse
|
12
|
Braissant O, Keiser J, Meister I, Bachmann A, Wirz D, Göpfert B, Bonkat G, Wadsö I. Isothermal microcalorimetry accurately detects bacteria, tumorous microtissues, and parasitic worms in a label-free well-plate assay. Biotechnol J 2015; 10:460-8. [PMID: 25511812 PMCID: PMC4406140 DOI: 10.1002/biot.201400494] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 11/07/2014] [Accepted: 12/15/2014] [Indexed: 12/04/2022]
Abstract
Isothermal microcalorimetry is a label-free assay that allows monitoring of enzymatic and metabolic activities. The technique has strengths, but most instruments have a low throughput, which has limited their use for bioassays. Here, an isothermal microcalorimeter, equipped with a vessel holder similar to a 48-well plate, was used. The increased throughput of this microcalorimeter makes it valuable for biomedical and pharmaceutical applications. Our results show that the sensitivity of the instrument allows the detection of 3 × 104 bacteria per vial. Growth of P. mirabilis in Luria Broth medium was detected between 2 and 9 h with decreasing inoculum. The culture released 2.1J with a maximum thermal power of 76 μW. The growth rate calculated using calorimetric and spectrophotometric data were 0.60 and 0.57 h–1, respectively. Additional insight on protease activities of P. mirabilis matching the last peak in heat production could be gathered as well. Growth of tumor microtissues releasing a maximum thermal power of 2.1 μW was also monitored and corresponds to a diameter increase of the microtissues from ca. 100 to 428 μm. This opens new research avenues in cancer research, diagnostics, and development of new antitumor drugs. For parasitic worms, the technique allows assessment of parasite survival using motor and metabolic activities even with a single worm.
Collapse
Affiliation(s)
- Olivier Braissant
- Center for Biomechanics and Biocalorimetry, c/o Biozentrum-Pharmazentrum, Basel, Switzerland; Department of Urology, University Hospital of Basel, Basel, Switzerland.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Development of a flow system for studying biofilm formation on medical devices with microcalorimetry. Methods 2014; 76:35-40. [PMID: 25498003 DOI: 10.1016/j.ymeth.2014.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 11/26/2014] [Accepted: 12/01/2014] [Indexed: 01/06/2023] Open
Abstract
Isothermal microcalorimetry (IMC) is particularly suited to the study of microbiological samples in complex or heterogeneous environments because it does not require optical clarity of the sample and can detect metabolic activity from as few as 10(4) CFU/mL cells. While the use of IMC for studying planktonic cultures is well established, in the clinical environment bacteria are most likely to be present as biofilms. Biofilm prevention and eradication present a number of challenges to designers and users of medical devices and implants, since bacteria in biofilm colonies are usually more resistant to antimicrobial agents. Analytical tools that facilitate investigation of biofilm formation are therefore extremely useful. While it is possible to study pre-prepared biofilms in closed ampoules, better correlation with in vivo behaviour can be achieved using a system in which the bacterial suspension is flowing. Here, we discuss the potential of flow microcalorimetry for studying biofilms and report the development of a simple flow system that can be housed in a microcalorimeter. The use of the flow system is demonstrated with biofilms of Staphylococcus aureus.
Collapse
|
14
|
Maskow T, Paufler S. What does calorimetry and thermodynamics of living cells tell us? Methods 2014; 76:3-10. [PMID: 25461814 DOI: 10.1016/j.ymeth.2014.10.035] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 10/23/2014] [Accepted: 10/28/2014] [Indexed: 02/08/2023] Open
Abstract
This article presents and compares several thermodynamic methods for the quantitative interpretation of data from calorimetric measurements. Heat generation and absorption are universal features of microbial growth and product formation as well as of cell cultures from animals, plants and insects. The heat production rate reflects metabolic changes in real time and is measurable on-line. The detection limit of commercially available calorimetric instruments can be low enough to measure the heat of 100,000 aerobically growing bacteria or of 100 myocardial cells. Heat can be monitored in reaction vessels ranging from a few nanoliters up to many cubic meters. Most important the heat flux measurement does not interfere with the biological process under investigation. The practical advantages of calorimetry include the waiver of labeling and reactants. It is further possible to assemble the thermal transducer in a protected way that reduces aging and thereby signal drifts. Calorimetry works with optically opaque solutions. All of these advantages make calorimetry an interesting method for many applications in medicine, environmental sciences, ecology, biochemistry and biotechnology, just to mention a few. However, in many cases the heat signal is merely used to monitor biological processes but only rarely to quantitatively interpret the data. Therefore, a significant proportion of the information potential of calorimetry remains unutilized. To fill this information gap and to motivate the reader using the full information potential of calorimetry, various methods for quantitative data interpretations are presented, evaluated and compared with each other. Possible errors of interpretation and limitations of quantitative data analysis are also discussed.
Collapse
Affiliation(s)
- Thomas Maskow
- UFZ, Helmholtz Centre for Environmental Research, Dept. Environmental Microbiology, Permoserstr. 15, D-04318 Leipzig, Germany.
| | - Sven Paufler
- UFZ, Helmholtz Centre for Environmental Research, Dept. Environmental Microbiology, Permoserstr. 15, D-04318 Leipzig, Germany.
| |
Collapse
|
15
|
Fechner P, Bleher O, Ewald M, Freudenberger K, Furin D, Hilbig U, Kolarov F, Krieg K, Leidner L, Markovic G, Proll G, Pröll F, Rau S, Riedt J, Schwarz B, Weber P, Widmaier J. Size does matter! Label-free detection of small molecule-protein interaction. Anal Bioanal Chem 2014; 406:4033-51. [PMID: 24817356 DOI: 10.1007/s00216-014-7834-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/07/2014] [Accepted: 04/11/2014] [Indexed: 11/28/2022]
Abstract
This review is focused on methods for detecting small molecules and, in particular, the characterisation of their interaction with natural proteins (e.g. receptors, ion channels). Because there are intrinsic advantages to using label-free methods over labelled methods (e.g. fluorescence, radioactivity), this review only covers label-free techniques. We briefly discuss available techniques and their advantages and disadvantages, especially as related to investigating the interaction between small molecules and proteins. The reviewed techniques include well-known and widely used standard analytical methods (e.g. HPLC-MS, NMR, calorimetry, and X-ray diffraction), newer and more specialised analytical methods (e.g. biosensors), biological systems (e.g. cell lines and animal models), and in-silico approaches.
Collapse
Affiliation(s)
- Peter Fechner
- Biametrics GmbH, Auf der Morgenstelle 18, 72076, Tübingen, Germany,
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Morais FM, Buchholz F, Maskow T. Chip calorimetry for evaluation of biofilm treatment with biocides, antibiotics, and biological agents. Methods Mol Biol 2014; 1147:267-275. [PMID: 24664840 DOI: 10.1007/978-1-4939-0467-9_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Any growth or bioconversion in biofilms is accompanied by the release of heat. The heat (in J) is tightly related to the stoichiometry of the respective process via law of Hess, and the heat production rate (in W or J/s) is additionally related to the process kinetics. This heat and the heat production rate can nowadays be measured by modern calorimetry with extremely high sensitivity. Flow-through calorimetry allows the measurement of bioprocesses in biofilms in real time, without the need of invasive sample preparation and disturbing of biofilm processes. Furthermore, it can be applied for long-term measurements and is even applicable to turbid media. Chip or miniaturized calorimeters have the additional advantages of extremely short thermal equilibration times and the requirement of very small amounts of media and chemicals. The precision of flow-through chip calorimeters (about 3 mW/L) allows the detection of early stages of biofilm development (about 10(5) bacteria cm(-2)).
Collapse
Affiliation(s)
- Frida Mariana Morais
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318, Leipzig, Germany
| | | | | |
Collapse
|