1
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Oikonomeas-Koppasis N, Ketzetzi S, Kraft DJ, Schall P. Power-law intermittency in the gradient-induced self-propulsion of colloidal swimmers. SOFT MATTER 2024. [PMID: 38868959 DOI: 10.1039/d4sm00603h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
Active colloidal microswimmers serve as archetypical active fluid systems, and as models for biological swimmers. Here, by studying in detail their velocity traces, we find robust power-law intermittency with system-dependent exponential cut off. We model the intermittent motion by an interplay of the field gradient-dependent active force, which depends on a fluid gradient and is reduced when the swimmer moves, and the locally fluctuating hydrodynamic drag, that is set by the wetting properties of the substrate. The model closely describes the velocity distributions of two disparate swimmer systems: AC field activated and catalytic swimmers. The generality is highlighted by the collapse of all data in a single master curve, suggesting the applicability to further systems, both synthetic and biological.
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Affiliation(s)
- Nick Oikonomeas-Koppasis
- Institute of Physics, University of Amsterdam, Science Park 904, P.O. Box 94485, 1090 GL, Amsterdam, The Netherlands.
| | - Stefania Ketzetzi
- Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - Daniela J Kraft
- Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - Peter Schall
- Institute of Physics, University of Amsterdam, Science Park 904, P.O. Box 94485, 1090 GL, Amsterdam, The Netherlands.
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2
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Bozuyuk U, Wrede P, Yildiz E, Sitti M. Roadmap for Clinical Translation of Mobile Microrobotics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2311462. [PMID: 38380776 DOI: 10.1002/adma.202311462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/24/2024] [Indexed: 02/22/2024]
Abstract
Medical microrobotics is an emerging field to revolutionize clinical applications in diagnostics and therapeutics of various diseases. On the other hand, the mobile microrobotics field has important obstacles to pass before clinical translation. This article focuses on these challenges and provides a roadmap of medical microrobots to enable their clinical use. From the concept of a "magic bullet" to the physicochemical interactions of microrobots in complex biological environments in medical applications, there are several translational steps to consider. Clinical translation of mobile microrobots is only possible with a close collaboration between clinical experts and microrobotics researchers to address the technical challenges in microfabrication, safety, and imaging. The clinical application potential can be materialized by designing microrobots that can solve the current main challenges, such as actuation limitations, material stability, and imaging constraints. The strengths and weaknesses of the current progress in the microrobotics field are discussed and a roadmap for their clinical applications in the near future is outlined.
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Affiliation(s)
- Ugur Bozuyuk
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Paul Wrede
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zurich, Zurich, 8093, Switzerland
| | - Erdost Yildiz
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- School of Medicine and College of Engineering, Koc University, Istanbul, 34450, Turkey
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3
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Bassu G, Laurati M, Fratini E. Transition from active motion to anomalous diffusion for Bacillus subtilis confined in hydrogel matrices. Colloids Surf B Biointerfaces 2024; 236:113797. [PMID: 38431996 DOI: 10.1016/j.colsurfb.2024.113797] [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: 08/02/2023] [Revised: 12/06/2023] [Accepted: 02/11/2024] [Indexed: 03/05/2024]
Abstract
We investigate the motility of B. subtilis under different degrees of confinement induced by transparent porous hydrogels. The dynamical behavior of the bacteria at short times is linked to characteristic parameters describing the hydrogel porosity. Mean squared displacements (MSDs) reveal that the run-and-tumble dynamics of unconfined B. subtilis progressively turns into sub-diffusive motion with increasing confinement. Correspondingly, the median instantaneous velocity of bacteria decreases and becomes more narrowly distributed, while the reorientation rate increases and reaches a plateau value. Analyzing single-trajectories, we show that the average dynamical behavior is the result of complex displacements, in which active, diffusive and sub-diffusive segments coexist. For small and moderate confinements, the number of active segments reduces, while the diffusive and sub-diffusive segments increase. The alternation of sub-diffusion, diffusion and active motion along the same trajectory can be described as a hopping ad trapping motion, in which hopping events correspond to displacements with an instantaneous velocity exceeding the corresponding mean value along a trajectory. Different from previous observations, escape from local trapping occurs for B. subtilis through active runs but also diffusion. Interestingly, the contribution of diffusion is maximum at intermediate confinements. At sufficiently long times transport coefficients estimated from the experimental MSDs under different degrees of confinement can be reproduced using a recently proposed hopping and trapping model. Finally, we propose a quantitative relationship linking the median velocity of confined and unconfined bacteria through the characteristic confinement length of the hydrogel matrix. Our work provides new insights for the bacterial motility in complex media that mimic natural environments and are relevant to important problems like sterilization, water purification, biofilm formation, membrane permeation and bacteria separation.
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Affiliation(s)
- Gavino Bassu
- Department of Chemistry "Ugo Schiff", Via della Lastruccia 3, Sesto Fiorentino 50019, Italy; Consorzio per lo Sviluppo dei Sistemi a Grande Interfase (CSGI)), Via della Lastruccia 3, Sesto Fiorentino 50019, Italy
| | - Marco Laurati
- Department of Chemistry "Ugo Schiff", Via della Lastruccia 3, Sesto Fiorentino 50019, Italy; Consorzio per lo Sviluppo dei Sistemi a Grande Interfase (CSGI)), Via della Lastruccia 3, Sesto Fiorentino 50019, Italy.
| | - Emiliano Fratini
- Department of Chemistry "Ugo Schiff", Via della Lastruccia 3, Sesto Fiorentino 50019, Italy; Consorzio per lo Sviluppo dei Sistemi a Grande Interfase (CSGI)), Via della Lastruccia 3, Sesto Fiorentino 50019, Italy
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4
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Papadopoulos C, Larue AE, Toulouze C, Mokhtari O, Lefort J, Libert E, Assémat P, Swider P, Malaquin L, Davit Y. A versatile micromodel technology to explore biofilm development in porous media flows. LAB ON A CHIP 2024; 24:254-271. [PMID: 38059908 DOI: 10.1039/d3lc00293d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Bacterial biofilms that grow in porous media are critical to ecosystem processes and applications ranging from soil bioremediation to bioreactors for treating wastewater or producing value-added products. However, understanding and engineering the complex phenomena that drive the development of biofilms in such systems remains a challenge. Here we present a novel micromodel technology to explore bacterial biofilm development in porous media flows. The technology consists of a set of modules that can be combined as required for any given experiment and conveniently tuned for specific requirements. The core module is a 3D-printed micromodel where biofilm is grown into a perfusable porous substrate. High-precision additive manufacturing, in particular stereolithography, is used to fabricate porous scaffolds with precisely controlled architectures integrating flow channels with diameters down to several hundreds of micrometers. The system is instrumented with: ultraviolet-C light-emitting diodes; on-line measurements of oxygen consumption and pressure drop across the porous medium; camera and spectrophotometric cells for the detection of biofilm detachment events at the outlet. We demonstrate how this technology can be used to study the development of Pseudomonas aeruginosa biofilm for several days within a network of flow channels. We find complex dynamics whereby oxygen consumption reaches a steady-state but not the pressure drop, which instead features a permanent regime with large fluctuations. We further use X-ray computed microtomography to image the spatial distribution of biofilms and computational fluid dynamics to link biofilm development with local flow properties. By combining the advantages of additive manufacturing for the creation of reproducible 3D porous microarchitectures with the flow control and instrumentation accuracy of microfluidics, our system provides a platform to study the dynamics of biofilm development in 3D porous media and to rapidly test new concepts in process engineering.
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Affiliation(s)
- Christos Papadopoulos
- Institut de Mécanique des Fluides (IMFT), CNRS & Université de Toulouse, 31400 Toulouse, France.
- LAAS-CNRS, CNRS & Université de Toulouse, 31400 Toulouse, France
| | - Anne Edith Larue
- Institut de Mécanique des Fluides (IMFT), CNRS & Université de Toulouse, 31400 Toulouse, France.
- Transverse Lab, 271 rue des Fontaines, 31300 Toulouse, France
| | - Clara Toulouze
- Institut de Mécanique des Fluides (IMFT), CNRS & Université de Toulouse, 31400 Toulouse, France.
| | - Omar Mokhtari
- Physikalisches Institut, Universität Bern, Gesellschaftsstrasse 6, 3012 Bern, Switzerland
| | - Julien Lefort
- Institut de Mécanique des Fluides (IMFT), CNRS & Université de Toulouse, 31400 Toulouse, France.
| | - Emmanuel Libert
- Institut de Mécanique des Fluides (IMFT), CNRS & Université de Toulouse, 31400 Toulouse, France.
| | - Pauline Assémat
- Institut de Mécanique des Fluides (IMFT), CNRS & Université de Toulouse, 31400 Toulouse, France.
| | - Pascal Swider
- Institut de Mécanique des Fluides (IMFT), CNRS & Université de Toulouse, 31400 Toulouse, France.
| | - Laurent Malaquin
- LAAS-CNRS, CNRS & Université de Toulouse, 31400 Toulouse, France
| | - Yohan Davit
- Institut de Mécanique des Fluides (IMFT), CNRS & Université de Toulouse, 31400 Toulouse, France.
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5
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Bondoc-Naumovitz KG, Laeverenz-Schlogelhofer H, Poon RN, Boggon AK, Bentley SA, Cortese D, Wan KY. Methods and Measures for Investigating Microscale Motility. Integr Comp Biol 2023; 63:1485-1508. [PMID: 37336589 PMCID: PMC10755196 DOI: 10.1093/icb/icad075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 06/21/2023] Open
Abstract
Motility is an essential factor for an organism's survival and diversification. With the advent of novel single-cell technologies, analytical frameworks, and theoretical methods, we can begin to probe the complex lives of microscopic motile organisms and answer the intertwining biological and physical questions of how these diverse lifeforms navigate their surroundings. Herein, we summarize the main mechanisms of microscale motility and give an overview of different experimental, analytical, and mathematical methods used to study them across different scales encompassing the molecular-, individual-, to population-level. We identify transferable techniques, pressing challenges, and future directions in the field. This review can serve as a starting point for researchers who are interested in exploring and quantifying the movements of organisms in the microscale world.
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Affiliation(s)
| | | | - Rebecca N Poon
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Alexander K Boggon
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Samuel A Bentley
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Dario Cortese
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Kirsty Y Wan
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
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6
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Mafla-Endara PM, Meklesh V, Beech JP, Ohlsson P, Pucetaite M, Hammer EC. Exposure to polystyrene nanoplastics reduces bacterial and fungal biomass in microfabricated soil models. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166503. [PMID: 37633381 DOI: 10.1016/j.scitotenv.2023.166503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/04/2023] [Accepted: 08/21/2023] [Indexed: 08/28/2023]
Abstract
Nanoplastics have been proven to induce toxicity in diverse organisms, yet their effect on soil microbes like bacteria and fungi remains largely unexplored. In this paper, we used micro-engineered soil models to investigate the effect of polystyrene (PS) nanospheres on Pseudomonas putida and Coprinopsis cinerea. Specifically, we explored the effects of increasing concentrations of 60 nm carboxylated bovine serum albumin (BSA) coated nanospheres (0, 0.5, 2, and 10 mg/L) on these bacterial and fungal model organisms respectively, over time. We found that both microorganisms could disperse through the PS solution, but long-distance dispersal was reduced by high concentrations. Microbial biomass decreased in all treatments, in which bacteria showed a linear dose response with the strongest effect at 10 mg/L concentration, and fungi showed a non-linear response with the strongest effect at 2 mg/L concentration. At the highest nanoplastics concentration, the first colonizing fungal hyphae adsorbed most of the PS nanospheres present in their vicinity, in a process that we termed the 'vacuum cleaner effect'. As a result, the toxicity effect of the original treatment on subsequently growing fungal hyphae was reduced to a growth level indistinguishable from the control. We did not find evidence that nanoplastics are able to penetrate bacterial nor fungal cell walls. Overall, our findings provide evidence that nanoplastics can cause a direct negative effect on soil microbes and highlight the need for further studies that can explain how the microbial stress response might affect soil functions.
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Affiliation(s)
- Paola M Mafla-Endara
- Centre for Environmental and Climate Science (CEC), Lund University, Lund, Sweden; Department of Biology, Lund University, Lund, Sweden.
| | - Viktoriia Meklesh
- Centre for Environmental and Climate Science (CEC), Lund University, Lund, Sweden; Physical Chemistry Division, Department of Chemistry, Lund University, Lund, Sweden
| | - Jason P Beech
- Division of Solid State Physics, Department of Physics and NanoLund, Lund University, Lund, Sweden
| | - Pelle Ohlsson
- Department of Biomedical Engineering, Faculty of Engineering (LTH), Lund University, Lund, Sweden
| | | | - Edith C Hammer
- Centre for Environmental and Climate Science (CEC), Lund University, Lund, Sweden; Department of Biology, Lund University, Lund, Sweden
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7
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Raza MR, George JE, Kumari S, Mitra MK, Paul D. Anomalous diffusion of E. coli under microfluidic confinement and chemical gradient. SOFT MATTER 2023; 19:6446-6457. [PMID: 37606542 DOI: 10.1039/d3sm00286a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
We report a two-layer microfluidic device to study the combined effect of confinement and chemical gradient on the motility of wild-type E. coli. We track individual E. coli in 50 μm and 10 μm wide microchannels, with a channel height of 2 μm, to generate quasi-2D conditions. We find that contrary to expectations, bacterial trajectories are superdiffusive even in the absence of a chemical (glucose) gradient. The superdiffusive behaviour becomes more pronounced upon introducing a chemical gradient or strengthening the lateral confinement. Run length distributions for weak lateral confinement in the absence of chemical gradients follow an exponential distribution. Both confinement and chemoattraction induce deviations from this behaviour, with the run length distributions approaching a power-law form under these conditions. Both confinement and chemoattraction suppress large-angle tumbles as well. Our results suggest that wild-type E. coli modulates both its runs and tumbles in a similar manner under physical confinement and chemical gradient. Our findings have implications for understanding how bacteria modulate their motility behaviour in natural habitats.
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Affiliation(s)
- Md Ramiz Raza
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
| | - Jijo Easo George
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
| | - Savita Kumari
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
| | - Mithun K Mitra
- Department of Physics, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Debjani Paul
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
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8
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Nandel V, Scadden J, Baker MAB. Ion-Powered Rotary Motors: Where Did They Come from and Where They Are Going? Int J Mol Sci 2023; 24:10601. [PMID: 37445779 PMCID: PMC10341847 DOI: 10.3390/ijms241310601] [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: 05/30/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Molecular motors are found in many living organisms. One such molecular machine, the ion-powered rotary motor (IRM), requires the movement of ions across a membrane against a concentration gradient to drive rotational movement. The bacterial flagellar motor (BFM) is an example of an IRM which relies on ion movement through the stator proteins to generate the rotation of the flagella. There are many ions which can be used by the BFM stators to power motility and different ions can be used by a single bacterium expressing multiple stator variants. The use of ancestral sequence reconstruction (ASR) and functional analysis of reconstructed stators shows promise for understanding how these proteins evolved and when the divergence in ion use may have occurred. In this review, we discuss extant BFM stators and the ions that power them as well as recent examples of the use of ASR to study ion-channel selectivity and how this might be applied to further study of the BFM stator complex.
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Affiliation(s)
| | | | - Matthew A. B. Baker
- School of Biotechnology and Biomolecular Sciences (BABS), University of New South Wales, Sydney, NSW 2033, Australia; (V.N.); (J.S.)
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9
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Formaglio P, Wosniack ME, Tromer RM, Polli JG, Matos YB, Zhong H, Raposo EP, da Luz MGE, Amino R. Plasmodium sporozoite search strategy to locate hotspots of blood vessel invasion. Nat Commun 2023; 14:2965. [PMID: 37221182 DOI: 10.1038/s41467-023-38706-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 05/10/2023] [Indexed: 05/25/2023] Open
Abstract
Plasmodium sporozoites actively migrate in the dermis and enter blood vessels to infect the liver. Despite their importance for malaria infection, little is known about these cutaneous processes. We combine intravital imaging in a rodent malaria model and statistical methods to unveil the parasite strategy to reach the bloodstream. We determine that sporozoites display a high-motility mode with a superdiffusive Lévy-like pattern known to optimize the location of scarce targets. When encountering blood vessels, sporozoites frequently switch to a subdiffusive low-motility behavior associated with probing for intravasation hotspots, marked by the presence of pericytes. Hence, sporozoites present anomalous diffusive motility, alternating between superdiffusive tissue exploration and subdiffusive local vessel exploitation, thus optimizing the sequential tasks of seeking blood vessels and pericyte-associated sites of privileged intravasation.
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Affiliation(s)
- Pauline Formaglio
- Institut Pasteur, Université Paris Cité, Malaria Infection and Immunity Unit, 75015, Paris, France
| | | | - Raphael M Tromer
- Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078- 970, Natal-RN, Brazil
| | - Jaderson G Polli
- Departamento de Física, Universidade Federal do Paraná, 81531-980, Curitiba-PR, Brazil
| | - Yuri B Matos
- Departamento de Física, Universidade Federal do Paraná, 81531-980, Curitiba-PR, Brazil
| | - Hang Zhong
- Institut Pasteur, Université Paris Cité, Malaria Infection and Immunity Unit, 75015, Paris, France
| | - Ernesto P Raposo
- Laboratório de Física Teórica e Computacional, Departamento de Física, Universidade Federal de Pernambuco, 50670-901, Recife-PE, Brazil
| | - Marcos G E da Luz
- Departamento de Física, Universidade Federal do Paraná, 81531-980, Curitiba-PR, Brazil.
| | - Rogerio Amino
- Institut Pasteur, Université Paris Cité, Malaria Infection and Immunity Unit, 75015, Paris, France.
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10
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Reliable cell retention of mammalian suspension cells in microfluidic cultivation chambers. Sci Rep 2023; 13:3857. [PMID: 36890160 PMCID: PMC9995442 DOI: 10.1038/s41598-023-30297-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 02/21/2023] [Indexed: 03/10/2023] Open
Abstract
Microfluidic cultivation, with its high level of environmental control and spatio-temporal resolution of cellular behavior, is a well-established tool in today's microfluidics. Yet, reliable retention of (randomly) motile cells inside designated cultivation compartments still represents a limitation, which prohibits systematic single-cell growth studies. To overcome this obstacle, current approaches rely on complex multilayer chips or on-chip valves, which makes their application for a broad community of users infeasible. Here, we present an easy-to-implement cell retention concept to withhold cells inside microfluidic cultivation chambers. By introducing a blocking structure into a cultivation chamber's entrance and nearly closing it, cells can be manually pushed into the chamber during loading procedures but are unable to leave it autonomously in subsequent long-term cultivation. CFD simulations as well as trace substance experiments confirm sufficient nutrient supply within the chamber. Through preventing recurring cell loss, growth data obtained from Chinese hamster ovary cultivation on colony level perfectly match data determined from single-cell data, which eventually allows reliable high throughput studies of single-cell growth. Due to its transferability to other chamber-based approaches, we strongly believe that our concept is also applicable for a broad range of cellular taxis studies or analyses of directed migration in basic or biomedical research.
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11
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Wisnoski NI, Lennon JT. Scaling up and down: movement ecology for microorganisms. Trends Microbiol 2023; 31:242-253. [PMID: 36280521 DOI: 10.1016/j.tim.2022.09.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
Movement is critical for the fitness of organisms, both large and small. It dictates how individuals acquire resources, evade predators, exchange genetic material, and respond to stressful environments. Movement also influences ecological and evolutionary dynamics at higher organizational levels, such as populations and communities. However, the links between individual motility and the processes that generate and maintain microbial diversity are poorly understood. Movement ecology is a framework linking the physiological and behavioral properties of individuals to movement patterns across scales of space, time, and biological organization. By synthesizing insights from cell biology, ecology, and evolution, we expand theory from movement ecology to predict the causes and consequences of microbial movements.
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Affiliation(s)
- Nathan I Wisnoski
- Wyoming Geographic Information Science Center, University of Wyoming, Laramie, WY 82071, USA; Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
| | - Jay T Lennon
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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12
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Bányai A, Farkas E, Jankovics H, Székács I, Tóth EL, Vonderviszt F, Horváth R, Varga M, Fürjes P. Dean-Flow Affected Lateral Focusing and Separation of Particles and Cells in Periodically Inhomogeneous Microfluidic Channels. SENSORS (BASEL, SWITZERLAND) 2023; 23:800. [PMID: 36679593 PMCID: PMC9865988 DOI: 10.3390/s23020800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/29/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
The purpose of the recent work is to give a better explanation of how Dean vortices affect lateral focusing, and to understand how cell morphology can alter the focusing position compared to spherical particles. The position and extent of the focused region were investigated using polystyrene fluorescent beads with different bead diameters (Ø = 0.5, 1.1, 1.97, 2.9, 4.8, 5.4, 6.08, 10.2, 15.8, 16.5 µm) at different flow rates (0.5, 1, 2 µL/s). Size-dependent focusing generated a precise map of the equilibrium positions of the spherical beads at the end of the periodically altering channels, which gave a good benchmark for focusing multi-dimensional particles and cells. The biological samples used for experiments were rod-shaped Escherichia coli (E. coli), discoid biconcave-shaped red blood cells (RBC), round or ovoid-shaped yeast, Saccharomyces cerevisiae, and soft-irregular-shaped HeLa cancer-cell-line cells to understand how the shape of the cells affects the focusing position at the end of the channel.
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Affiliation(s)
- Anita Bányai
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Eötvös Loránd Research Network, Konkoly Thege Miklós Str. 29-33, H-1121 Budapest, Hungary
- 77 Elektronika Ltd., Fehérvári Str. 98, H-1111 Budapest, Hungary
- Doctoral School on Materials Sciences and Technologies, Óbuda University, Bécsi Str. 96/B, H-1034 Budapest, Hungary
| | - Enikő Farkas
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Eötvös Loránd Research Network, Konkoly Thege Miklós Str. 29-33, H-1121 Budapest, Hungary
| | - Hajnalka Jankovics
- Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Egyetem Str. 10, H-8200 Veszprém, Hungary
| | - Inna Székács
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Eötvös Loránd Research Network, Konkoly Thege Miklós Str. 29-33, H-1121 Budapest, Hungary
| | - Eszter Leelőssyné Tóth
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Eötvös Loránd Research Network, Konkoly Thege Miklós Str. 29-33, H-1121 Budapest, Hungary
| | - Ferenc Vonderviszt
- Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Egyetem Str. 10, H-8200 Veszprém, Hungary
| | - Róbert Horváth
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Eötvös Loránd Research Network, Konkoly Thege Miklós Str. 29-33, H-1121 Budapest, Hungary
| | - Máté Varga
- 77 Elektronika Ltd., Fehérvári Str. 98, H-1111 Budapest, Hungary
| | - Péter Fürjes
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Eötvös Loránd Research Network, Konkoly Thege Miklós Str. 29-33, H-1121 Budapest, Hungary
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13
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On the mean path length invariance property for random walks of animals in open environment. Sci Rep 2022; 12:19800. [PMID: 36396773 PMCID: PMC9672306 DOI: 10.1038/s41598-022-24361-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022] Open
Abstract
Random walks are common in nature and are at the basis of many different phenomena that span from neutrons and light scattering to the behaviour of animals. Despite the evident differences among all these phenomena, theory predicts that they all share a common fascinating feature known as Invariance Property (IP). In a nutshell, IP means that the mean length of the total path of a random walker inside a closed domain is fixed by the geometry and size of the medium. Such a property has been demonstrated to hold not only in optics, but recently also in the field of biology, by studying the movement of bacteria. However, the range of validity of such a universal property, strictly linked to the fulfilment of equilibrium conditions and to the statistical distributions of the steps of the random walkers, is not trivial and needs to be studied in different contexts, such as in the case of biological entities occupied in random foraging in an open environment. Hence, in this paper the IP in a virtual medium inside an open environment has been studied by using actual movements of animals recorded in nature. In particular, we analysed the behaviour of a grazer mollusc, the chiton Acanthopleura granulata. The results depart from those predicted by the IP when the dimension of the medium increases. Such findings are framed in both the condition of nonequilibrium of the walkers, which is typical of animals in nature, and the characteristics of actual animal movements.
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Bacteria-on-a-bead: probing the hydrodynamic interplay of dynamic cell appendages during cell separation. Commun Biol 2022; 5:1093. [PMID: 36241769 PMCID: PMC9568603 DOI: 10.1038/s42003-022-04026-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 09/23/2022] [Indexed: 11/08/2022] Open
Abstract
Surface attachment of bacteria is the first step of biofilm formation and is often mediated and coordinated by the extracellular appendages, flagellum and pili. The model organism Caulobacter crescentus undergoes an asymmetric division cycle, giving rise to a motile "swarmer cell" and a sessile "stalked cell", which is attached to the surface. In the highly polarized predivisional cell, pili and flagellum, which are assembled at the pole opposite the stalk, are both activated before and during the process of cell separation. We explored the interplay of flagellum and active pili by growing predivisional cells on colloidal beads, creating a bacteria-on-a-bead system. Using this set-up, we were able to simultaneously visualize the bacterial motility and analyze the dynamics of the flagellum and pili during cell separation. The observed activities of flagellum and pili at the new cell pole of the predivisional cell result in a cooperating interplay of the appendages during approaching and attaching to a surface. Even in presence of a functioning flagellum, pili are capable of surface attachment and keeping the cell in position. Moreover, while flagellar rotation decreases the average attachment time of a single pilus, it increases the overall attachment rate of pili in a synergetic manner.
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Lynch JB, James N, McFall-Ngai M, Ruby EG, Shin S, Takagi D. Transitioning to confined spaces impacts bacterial swimming and escape response. Biophys J 2022; 121:2653-2662. [PMID: 35398019 PMCID: PMC9300662 DOI: 10.1016/j.bpj.2022.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/28/2021] [Accepted: 04/05/2022] [Indexed: 11/02/2022] Open
Abstract
Symbiotic bacteria often navigate complex environments before colonizing privileged sites in their host organism. Chemical gradients are known to facilitate directional taxis of these bacteria, guiding them toward their eventual destination. However, less is known about the role of physical features in shaping the path the bacteria take and defining how they traverse a given space. The flagellated marine bacterium Vibrio fischeri, which forms a binary symbiosis with the Hawaiian bobtail squid, Euprymna scolopes, must navigate tight physical confinement during colonization, squeezing through a tissue bottleneck constricting to ∼2 μm in width on the way to its eventual home. Using microfluidic in vitro experiments, we discovered that V. fischeri cells alter their behavior upon entry into confined space, straightening their swimming paths and promoting escape from confinement. Using a computational model, we attributed this escape response to two factors: reduced directional fluctuation and a refractory period between reversals. Additional experiments in asymmetric capillary tubes confirmed that V. fischeri quickly escape from confined ends, even when drawn into the ends by chemoattraction. This avoidance was apparent down to a limit of confinement approaching the diameter of the cell itself, resulting in a balance between chemoattraction and evasion of physical confinement. Our findings demonstrate that nontrivial distributions of swimming bacteria can emerge from simple physical gradients in the level of confinement. Tight spaces may serve as an additional, crucial cue for bacteria while they navigate complex environments to enter specific habitats.
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Affiliation(s)
- Jonathan B Lynch
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i.
| | - Nicholas James
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Margaret McFall-Ngai
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Edward G Ruby
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Sangwoo Shin
- Department of Mechanical Engineering, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York
| | - Daisuke Takagi
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mechanical Engineering, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mathematics, University of Hawai'i at Mānoa, Honolulu, Hawai'i
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Ishikawa T. Bacterial behaviors in confined diorama environments. Biophys J 2022; 121:2487-2489. [PMID: 35690064 DOI: 10.1016/j.bpj.2022.05.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/02/2022] [Accepted: 05/27/2022] [Indexed: 11/02/2022] Open
Affiliation(s)
- Takuji Ishikawa
- Department of Biomedical Engineering, Tohoku University, Sendai, Japan.
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Zhu X, Wang K, Yan H, Liu C, Zhu X, Chen B. Microfluidics as an Emerging Platform for Exploring Soil Environmental Processes: A Critical Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:711-731. [PMID: 34985862 DOI: 10.1021/acs.est.1c03899] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Investigating environmental processes, especially those occurring in soils, calls for innovative and multidisciplinary technologies that can provide insights at the microscale. The heterogeneity, opacity, and dynamics make the soil a "black box" where interactions and processes are elusive. Recently, microfluidics has emerged as a powerful research platform and experimental tool which can create artificial soil micromodels, enabling exploring soil processes on a chip. Micro/nanofabricated microfluidic devices can mimic some of the key features of soil with highly controlled physical and chemical microenvironments at the scale of pores, aggregates, and microbes. The combination of various techniques makes microfluidics an integrated approach for observation, reaction, analysis, and characterization. In this review, we systematically summarize the emerging applications of microfluidic soil platforms, from investigating soil interfacial processes and soil microbial processes to soil analysis and high-throughput screening. We highlight how innovative microfluidic devices are used to provide new insights into soil processes, mechanisms, and effects at the microscale, which contribute to an integrated interrogation of the soil systems across different scales. Critical discussions of the practical limitations of microfluidic soil platforms and perspectives of future research directions are summarized. We envisage that microfluidics will represent the technological advances toward microscopic, controllable, and in situ soil research.
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Affiliation(s)
- Xiangyu Zhu
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310058, China
| | - Kun Wang
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310058, China
| | - Huicong Yan
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310058, China
| | - Congcong Liu
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310058, China
| | - Xiaoying Zhu
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310058, China
| | - Baoliang Chen
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang 310058, China
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Abstract
<abstract>
<p>Digital holographic microscopy provides the ability to observe throughout a large volume without refocusing. This capability enables simultaneous observations of large numbers of microorganisms swimming in an essentially unconstrained fashion. However, computational tools for tracking large 4D datasets remain lacking. In this paper, we examine the errors introduced by tracking bacterial motion as 2D projections vs. 3D volumes under different circumstances: bacteria free in liquid media and bacteria near a glass surface. We find that while XYZ speeds are generally equal to or larger than XY speeds, they are still within empirical uncertainties. Additionally, when studying dynamic surface behavior, the Z coordinate cannot be neglected.</p>
</abstract>
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