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Luo X, Vo T, Jambi F, Pham P, Choy JS. Microfluidic partition with in situ biofabricated semipermeable biopolymer membranes for static gradient generation. LAB ON A CHIP 2016; 16:3815-3823. [PMID: 27713976 DOI: 10.1039/c6lc00742b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We report an in situ biofabrication strategy that conveniently partitions microfluidic networks into physically separated while chemically communicating microchannels with semipermeable biopolymer membranes, which enable the facile generation of static gradients for biomedical applications. The biofabrication of parallel biopolymer membranes was initiated with the dissipation of trapped air bubbles in parallel apertures in polydimethylsiloxane (PDMS) microfluidic devices, followed by tunable membrane growth with precise temporal and spatial control to the desired thickness. Static gradients were generated within minutes and well maintained over time by pure diffusion of molecules through the biofabricated semipermeable membranes. As an example application, the static gradient of alpha factor was generated to study the development of the "shmoo" morphology of yeast over time. The in situ biofabrication provides a simple approach to generate static gradients and an ideal platform for biological applications where flow-free static gradients are indispensable.
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Affiliation(s)
- Xiaolong Luo
- Department of Mechanical Engineering, The Catholic University of America, Washington, D.C. 20064, USA.
| | - Thanh Vo
- Department of Mechanical Engineering, The Catholic University of America, Washington, D.C. 20064, USA.
| | - Fahad Jambi
- Department of Mechanical Engineering, The Catholic University of America, Washington, D.C. 20064, USA.
| | - Phu Pham
- Department of Mechanical Engineering, The Catholic University of America, Washington, D.C. 20064, USA.
| | - John S Choy
- Department of Biology, The Catholic University of America, Washington, D.C. 20064, USA
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52
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Oliveira AF, Pessoa ACSN, Bastos RG, de la Torre LG. Microfluidic tools toward industrial biotechnology. Biotechnol Prog 2016; 32:1372-1389. [DOI: 10.1002/btpr.2350] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 08/15/2016] [Indexed: 01/29/2023]
Affiliation(s)
- Aline F. Oliveira
- Department of Bioprocesses and Materials Engineering, School of Chemical Engineering, University of Campinas; 500 Albert Einstein avenue Campinas P.O. Box 6066
| | - Amanda C. S. N. Pessoa
- Department of Bioprocesses and Materials Engineering, School of Chemical Engineering, University of Campinas; 500 Albert Einstein avenue Campinas P.O. Box 6066
| | - Reinaldo G. Bastos
- Department of Agroindustrial Technology and Rural Socioeconomy, Center of Agricultural Sciences, Federal University of São Carlos; Km 174 Anhanguera Highway Araras P.O. Box 153
| | - Lucimara G. de la Torre
- Department of Bioprocesses and Materials Engineering, School of Chemical Engineering, University of Campinas; 500 Albert Einstein avenue Campinas P.O. Box 6066
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53
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Kim BJ, Chu I, Jusuf S, Kuo T, TerAvest MA, Angenent LT, Wu M. Oxygen Tension and Riboflavin Gradients Cooperatively Regulate the Migration of Shewanella oneidensis MR-1 Revealed by a Hydrogel-Based Microfluidic Device. Front Microbiol 2016; 7:1438. [PMID: 27703448 PMCID: PMC5028412 DOI: 10.3389/fmicb.2016.01438] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/30/2016] [Indexed: 11/13/2022] Open
Abstract
Shewanella oneidensis is a model bacterial strain for studies of bioelectrochemical systems (BESs). It has two extracellular electron transfer pathways: (1) shuttling electrons via an excreted mediator riboflavin; and (2) direct contact between the c-type cytochromes at the cell membrane and the electrode. Despite the extensive use of S. oneidensis in BESs such as microbial fuel cells and biosensors, many basic microbiology questions about S. oneidensis in the context of BES remain unanswered. Here, we present studies of motility and chemotaxis of S. oneidensis under well controlled concentration gradients of two electron acceptors, oxygen and oxidized form of riboflavin (flavin+), using a newly developed microfluidic platform. Experimental results demonstrate that either oxygen or flavin+ is a chemoattractant to S. oneidensis. The chemotactic tendency of S. oneidensis in a flavin+ concentration gradient is significantly enhanced in an anaerobic in contrast to an aerobic condition. Furthermore, either a low oxygen tension or a high flavin+ concentration considerably enhances the speed of S. oneidensis. This work presents a robust microfluidic platform for generating oxygen and/or flavin+ gradients in an aqueous environment, and demonstrates that two important electron acceptors, oxygen and oxidized riboflavin, cooperatively regulate S. oneidensis migration patterns. The microfluidic tools presented as well as the knowledge gained in this work can be used to guide the future design of BESs for efficient electron production.
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Affiliation(s)
- Beum Jun Kim
- Department of Biological and Environmental Engineering, Cornell University Ithaca, NY, USA
| | - Injun Chu
- School of Chemical and Biomolecular Engineering, Cornell University Ithaca, NY, USA
| | - Sebastian Jusuf
- Department of Biological and Environmental Engineering, Cornell University Ithaca, NY, USA
| | - Tiffany Kuo
- Department of Biological and Environmental Engineering, Cornell University Ithaca, NY, USA
| | - Michaela A TerAvest
- Department of Biological and Environmental Engineering, Cornell University Ithaca, NY, USA
| | - Largus T Angenent
- Department of Biological and Environmental Engineering, Cornell UniversityIthaca, NY, USA; Atkinson Center for a Sustainable Future, Cornell UniversityIthaca, NY, USA
| | - Mingming Wu
- Department of Biological and Environmental Engineering, Cornell UniversityIthaca, NY, USA; Atkinson Center for a Sustainable Future, Cornell UniversityIthaca, NY, USA
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54
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Chemotaxis of bio-hybrid multiple bacteria-driven microswimmers. Sci Rep 2016; 6:32135. [PMID: 27555465 PMCID: PMC4995368 DOI: 10.1038/srep32135] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 08/03/2016] [Indexed: 11/16/2022] Open
Abstract
In this study, in a bio-hybrid microswimmer system driven by multiple Serratia marcescens bacteria, we quantify the chemotactic drift of a large number of microswimmers towards L-serine and elucidate the associated collective chemotaxis behavior by statistical analysis of over a thousand swimming trajectories of the microswimmers. The results show that the microswimmers have a strong heading preference for moving up the L-serine gradient, while their speed does not change considerably when moving up and down the gradient; therefore, the heading bias constitutes the major factor that produces the chemotactic drift. The heading direction of a microswimmer is found to be significantly more persistent when it moves up the L-serine gradient than when it travels down the gradient; this effect causes the apparent heading preference of the microswimmers and is the crucial reason that enables the seemingly cooperative chemotaxis of multiple bacteria on a microswimmer. In addition, we find that their chemotactic drift velocity increases superquadratically with their mean swimming speed, suggesting that chemotaxis of bio-hybrid microsystems can be enhanced by designing and building faster microswimmers. Such bio-hybrid microswimmers with chemotactic steering capability may find future applications in targeted drug delivery, bioengineering, and lab-on-a-chip devices.
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55
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Ondera TJ, Hamme AT. Magnetic-optical nanohybrids for targeted detection, separation, and photothermal ablation of drug-resistant pathogens. Analyst 2016; 140:7902-11. [PMID: 26469636 DOI: 10.1039/c5an00497g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A rapid, sensitive and quantitative immunoassay for the targeted detection and decontamination of E. coli based on Fe3O4 magnetic nanoparticles (MNPs) and plasmonic popcorn-shaped gold nanostructure attached single-walled carbon nanotubes (AuNP@SWCNT) is presented. The MNPs were synthesized as the support for a monoclonal antibody (mAb@MNP). E. coli (49979) was captured and rapidly preconcentrated from the sample with the mAb@MNP, followed by binding with Raman-tagged concanavalin A-AuNP@SWCNTs (Con A-AuNP@SWCNTs) as detector nanoprobes. A Raman tag 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) generated a Raman signal upon 670 nm laser excitation enabling the detection and quantification of E. coli concentration with a limit of detection of 10(2) CFU mL(-1) and a linear logarithmic response range of 1.0 × 10(2) to 1.0 × 10(7) CFU mL(-1). The mAb@MNP could remove more than 98% of E. coli (initial concentration of 1.3 × 10(4) CFU mL(-1)) from water. The potential of the immunoassay to detect E. coli bacteria in real water samples was investigated and the results were compared with the experimental results from the classical count method. There was no statistically significant difference between the two methods (p > 0.05). Furthermore, the MNP/AuNP@SWCNT hybrid system exhibits an enhanced photothermal killing effect. The sandwich-like immunoassay possesses potential for rapid bioanalysis and the simultaneous biosensing of multiple pathogenic agents.
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Affiliation(s)
- Thomas J Ondera
- Department of Chemistry and Biochemistry, Jackson State University, 1400 J R Lynch street, Jackson, MS 39217, USA.
| | - Ashton T Hamme
- Department of Chemistry and Biochemistry, Jackson State University, 1400 J R Lynch street, Jackson, MS 39217, USA.
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56
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Velegol D, Garg A, Guha R, Kar A, Kumar M. Origins of concentration gradients for diffusiophoresis. SOFT MATTER 2016; 12:4686-4703. [PMID: 27174044 DOI: 10.1039/c6sm00052e] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Fluid transport that is driven by gradients of pressure, gravity, or electro-magnetic potential is well-known and studied in many fields. A subtler type of transport, called diffusiophoresis, occurs in a gradient of chemical concentration, either electrolyte or non-electrolyte. Diffusiophoresis works by driving a slip velocity at the fluid-solid interface. Although the mechanism is well-known, the diffusiophoresis mechanism is often considered to be an esoteric laboratory phenomenon. However, in this article we show that concentration gradients can develop in a surprisingly wide variety of physical phenomena - imposed gradients, asymmetric reactions, dissolution, crystallization, evaporation, mixing, sedimentation, and others - so that diffusiophoresis is in fact a very common transport mechanism, in both natural and artificial systems. We anticipate that in georeservoir extractions, physiological systems, drying operations, laboratory and industrial separations, crystallization operations, membrane processes, and many other situations, diffusiophoresis is already occurring - often without being recognized - and that opportunities exist for designing this transport to great advantage.
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Affiliation(s)
- Darrell Velegol
- Department of Chemical Engineering, Penn State University, University Park, PA 16802, USA.
| | - Astha Garg
- Department of Chemical Engineering, Penn State University, University Park, PA 16802, USA.
| | - Rajarshi Guha
- Department of Chemical Engineering, Penn State University, University Park, PA 16802, USA.
| | - Abhishek Kar
- Department of Chemical Engineering, Penn State University, University Park, PA 16802, USA.
| | - Manish Kumar
- Department of Chemical Engineering, Penn State University, University Park, PA 16802, USA.
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57
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Katuri J, Seo KD, Kim DS, Sánchez S. Artificial micro-swimmers in simulated natural environments. LAB ON A CHIP 2016; 16:1101-1105. [PMID: 26882472 DOI: 10.1039/c6lc90022d] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Microswimmers, such as bacteria, are known to show different behaviours depending on their local environment. They identify spatial chemical gradients to find nutrient rich areas (chemotaxis) and interact with shear flows to accumulate in high shear regions. Recently, artificial microswimmers have been developed which mimic their natural counterparts in many ways. One of the exciting topics in this field is to study these artificial motors in several natural settings like the ones bacteria interact with. In this Focus article, we summarize recent observations of artificial swimmers in chemical gradients, shear flows and other interesting natural environments simulated in the lab using microfluidics and nanotechnology.
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Affiliation(s)
- J Katuri
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569, Stuttgart, Germany. and Institute for Bioengineering of Catalonia (IBEC), Baldiri I Reixac 10-12, 08028 Barcelona, Spain.
| | - K D Seo
- Department of Mechanical Engineering, POSTECH (Pohang University of Science and Technology), Pohang, Gyeongbuk, 790-784 Korea
| | - D S Kim
- Department of Mechanical Engineering, POSTECH (Pohang University of Science and Technology), Pohang, Gyeongbuk, 790-784 Korea
| | - S Sánchez
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569, Stuttgart, Germany. and Institute for Bioengineering of Catalonia (IBEC), Baldiri I Reixac 10-12, 08028 Barcelona, Spain. and Catalan Institute for Research and Advanced Studies (ICREA), Psg. Lluís Companys, 23, 08010 Barcelona, Spain
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58
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A review of chemical gradient systems for cell analysis. Anal Chim Acta 2016; 907:7-17. [DOI: 10.1016/j.aca.2015.12.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 12/01/2015] [Accepted: 12/12/2015] [Indexed: 01/22/2023]
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59
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Zhou SF, Gopalakrishnan S, Xu YH, Yang J, Lam YW, Pang SW. A Unidirectional Cell Switching Gate by Engineering Grating Length and Bending Angle. PLoS One 2016; 11:e0147801. [PMID: 26821058 PMCID: PMC4731054 DOI: 10.1371/journal.pone.0147801] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 01/09/2016] [Indexed: 11/18/2022] Open
Abstract
On a microgrooved substrate, cells migrate along the pattern, and at random positions, reverse their directions. Here, we demonstrate that these reversals can be controlled by introducing discontinuities to the pattern. On "V-shaped grating patterns", mouse osteogenic progenitor MC3T3-E1 cells reversed predominately at the bends and the ends. The patterns were engineered in a way that the combined effects of angle- and length-dependence could be examined in addition to their individual effects. Results show that when the bend was placed closer to one end, migration behaviour of cells depends on their direction of approach. At an obtuse bend (135°), more cells reversed when approaching from the long segment than from the short segment. But at an acute bend (45°), this relationship was reversed. Based on this anisotropic behaviour, the designed patterns effectively allowed cells to move in one direction but blocked migrations in the opposing direction. This study demonstrates that by the strategic placement of bends and ends on grating patterns, we can engineer effective unidirectional switching gates that can control the movement of adherent cells. The knowledge developed in this study could be utilised in future cell sorting or filtering platforms without the need for chemotaxis or microfluidic control.
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Affiliation(s)
- Shu Fan Zhou
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong
- Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong
| | - Singaram Gopalakrishnan
- Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong
- Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Yuan Hao Xu
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong
- Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong
| | - Jie Yang
- Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong
- Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Yun Wah Lam
- Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong
- Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Stella W Pang
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong
- Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong
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60
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Oliveira A, Pelegati V, Carvalho H, Cesar C, Bastos R, de la Torre L. Cultivation of yeast in diffusion-based microfluidic device. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2015.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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61
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Hejazian M, Phan DT, Nguyen NT. Mass transport improvement in microscale using diluted ferrofluid and a non-uniform magnetic field. RSC Adv 2016. [DOI: 10.1039/c6ra11703a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We investigate the mass transport enhancement of a non-magnetic fluorescent dye with the help of diluted ferrofluid and a non-uniform magnetic field.
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Affiliation(s)
- Majid Hejazian
- Queensland Micro- and Nanotechnology Center
- Griffith University
- Australia
| | - Dinh-Tuan Phan
- School of Mechanical and Aerospace Engineering
- Nanyang Technological University
- Singapore
| | - Nam-Trung Nguyen
- Queensland Micro- and Nanotechnology Center
- Griffith University
- Australia
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62
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Park CY, Jacobson DR, Nguyen DT, Willardson S, Saleh OA. A thin permeable-membrane device for single-molecule manipulation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:014301. [PMID: 26827332 DOI: 10.1063/1.4939197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Single-molecule manipulation instruments have unparalleled abilities to interrogate the structure and elasticity of single biomolecules. Key insights are derived by measuring the system response in varying solution conditions; yet, typical solution control strategies require imposing a direct fluid flow on the measured biomolecule that perturbs the high-sensitivity measurement and/or removes interacting molecules by advection. An alternate approach is to fabricate devices that permit solution changes by diffusion of the introduced species through permeable membranes, rather than by direct solution flow through the sensing region. Prior implementations of permeable-membrane devices are relatively thick, disallowing their use in apparatus that require the simultaneous close approach of external instrumentation from two sides, as occurs in single-molecule manipulation devices like the magnetic tweezer. Here, we describe the construction and use of a thin microfluidic device appropriate for single-molecule studies. We create a flow cell of only ∼500 μm total thickness by sandwiching glass coverslips around a thin plastic gasket and then create permeable walls between laterally separated channels in situ through photo-induced cross-linking of poly(ethylene glycol) diacrylate hydrogels. We show that these membranes permit passage of ions and small molecules (thus permitting solution equilibration in the absence of direct flow), but the membranes block the passage of larger biomolecules (thus retaining precious samples). Finally, we demonstrate the suitability of the device for high-resolution magnetic-tweezer experiments by measuring the salt-dependent folding of a single RNA hairpin under force.
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Affiliation(s)
- Chang-Young Park
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA
| | - David R Jacobson
- Physics Department, University of California, Santa Barbara, California 93106, USA
| | - Dan T Nguyen
- BMSE Program, University of California, Santa Barbara, California 93106, USA
| | - Sam Willardson
- MCDB Department, University of California, Santa Barbara, California 93106, USA
| | - Omar A Saleh
- Materials Department and BMSE Program, University of California, Santa Barbara, California 93106, USA
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63
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Hu C, Lin YS, Chen H, Liu J, Nie F. Concentration gradient generator for H460 lung cancer cell sensitivity to resist the cytotoxic action of curcumin in microenvironmental pH conditions. RSC Adv 2016. [DOI: 10.1039/c6ra20804e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We proposed and demonstrated a concentration gradient generator (CGG) to resist H460 lung cancer cells using curcumin in microenvironmental pH conditions.
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Affiliation(s)
- Chunfei Hu
- Laboratory of Biosensing Technology
- School of Life Sciences
- Shanghai University
- Shanghai 200444
- China
| | - Yu-Sheng Lin
- Division of Nanobionic Research
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
| | - Hongmei Chen
- Division of Nanobionic Research
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
| | - Jingjing Liu
- Division of Nanobionic Research
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
| | - Fuqiang Nie
- Division of Nanobionic Research
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
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64
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Central Nervous System and its Disease Models on a Chip. Trends Biotechnol 2015; 33:762-776. [DOI: 10.1016/j.tibtech.2015.09.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/18/2015] [Accepted: 09/08/2015] [Indexed: 01/17/2023]
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65
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Lalanne-Aulet D, Piacentini A, Guillot P, Marchal P, Moreau G, Colin A. Multiscale study of bacterial growth: Experiments and model to understand the impact of gas exchange on global growth. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:052706. [PMID: 26651722 DOI: 10.1103/physreve.92.052706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Indexed: 06/05/2023]
Abstract
Using a millifluidics and macroscale setup, we study quantitatively the impact of gas exchange on bacterial growth. In millifluidic environments, the permeability of the incubator materials allows an unlimited oxygen supply by diffusion. Moreover, the efficiency of diffusion at small scales makes the supply instantaneous in comparison with the cell division time. In hermetic closed vials, the amount of available oxygen is low. The growth curve has the same trend but is quantitatively different from the millifluidic situation. The analysis of all the data allows us to write a quantitative modeling enabling us to capture the entire growth process.
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Affiliation(s)
| | | | - Pierre Guillot
- University of Bordeaux, CNRS, Solvay, LOF UMR 5258, France
| | - Philippe Marchal
- Solvay, Centre de Recherches de Lyon, 85 rue des Frères Perret, Saint-Fons, France
| | - Gilles Moreau
- Solvay, Centre de Recherches de Lyon, 85 rue des Frères Perret, Saint-Fons, France
| | - Annie Colin
- ESPCI, CNRS, SIMM UMR 7615, 11 rue Vauquelin, 75005 Paris, France
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66
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Yang M, Liu R, Ripoll M, Chen K. A microscale turbine driven by diffusive mass flux. LAB ON A CHIP 2015; 15:3912-3917. [PMID: 26288078 DOI: 10.1039/c5lc00479a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An external diffusive mass flux is shown to be able to generate a mechanical torque on a microscale object based on anisotropic diffusiophoresis. In light of this finding, we propose a theoretical prototype micro-turbine driven purely by diffusive mass flux, which is in strong contrast to conventional turbines driven by convective mass flows. The rotational velocity of the proposed turbine is determined by the external concentration gradient, the geometry and the diffusiophoretic properties of the turbine. This scenario is validated by performing computer simulations. Our finding thus provides a new type of chemo-mechanical response which could be used to exploit existing chemical energies at small scales.
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Affiliation(s)
- Mingcheng Yang
- Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
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67
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Integrative Utilization of Microenvironments, Biomaterials and Computational Techniques for Advanced Tissue Engineering. J Biotechnol 2015; 212:71-89. [DOI: 10.1016/j.jbiotec.2015.08.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 08/02/2015] [Accepted: 08/11/2015] [Indexed: 01/13/2023]
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68
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Cho S, Choi YJ, Zheng S, Han J, Ko SY, Park JO, Park S. Modeling of chemotactic steering of bacteria-based microrobot using a population-scale approach. BIOMICROFLUIDICS 2015; 9:054116. [PMID: 26487902 PMCID: PMC4592439 DOI: 10.1063/1.4932304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 09/22/2015] [Indexed: 05/04/2023]
Abstract
The bacteria-based microrobot (Bacteriobot) is one of the most effective vehicles for drug delivery systems. The bacteriobot consists of a microbead containing therapeutic drugs and bacteria as a sensor and an actuator that can target and guide the bacteriobot to its destination. Many researchers are developing bacteria-based microrobots and establishing the model. In spite of these efforts, a motility model for bacteriobots steered by chemotaxis remains elusive. Because bacterial movement is random and should be described using a stochastic model, bacterial response to the chemo-attractant is difficult to anticipate. In this research, we used a population-scale approach to overcome the main obstacle to the stochastic motion of single bacterium. Also known as Keller-Segel's equation in chemotaxis research, the population-scale approach is not new. It is a well-designed model derived from transport theory and adaptable to any chemotaxis experiment. In addition, we have considered the self-propelled Brownian motion of the bacteriobot in order to represent its stochastic properties. From this perspective, we have proposed a new numerical modelling method combining chemotaxis and Brownian motion to create a bacteriobot model steered by chemotaxis. To obtain modeling parameters, we executed motility analyses of microbeads and bacteriobots without chemotactic steering as well as chemotactic steering analysis of the bacteriobots. The resulting proposed model shows sound agreement with experimental data with a confidence level <0.01.
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Affiliation(s)
- Sunghoon Cho
- School of Mechanical Engineering, Chonnam National University , 300, Yongbong-dong, Buk-gu, Gwangju, South Korea
| | - Young Jin Choi
- School of Mechanical Engineering, Chonnam National University , 300, Yongbong-dong, Buk-gu, Gwangju, South Korea
| | - Shaohui Zheng
- School of Mechanical Engineering, Chonnam National University , 300, Yongbong-dong, Buk-gu, Gwangju, South Korea
| | - Jiwon Han
- School of Mechanical Engineering, Chonnam National University , 300, Yongbong-dong, Buk-gu, Gwangju, South Korea
| | - Seong Young Ko
- School of Mechanical Engineering, Chonnam National University , 300, Yongbong-dong, Buk-gu, Gwangju, South Korea
| | - Jong-Oh Park
- School of Mechanical Engineering, Chonnam National University , 300, Yongbong-dong, Buk-gu, Gwangju, South Korea
| | - Sukho Park
- School of Mechanical Engineering, Chonnam National University , 300, Yongbong-dong, Buk-gu, Gwangju, South Korea
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69
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Quantitative analysis of Caenorhabditis elegans chemotaxis using a microfluidic device. Anal Chim Acta 2015; 887:155-162. [PMID: 26320797 DOI: 10.1016/j.aca.2015.07.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 04/24/2015] [Accepted: 07/17/2015] [Indexed: 11/24/2022]
Abstract
Caenorhabditis elegans, one of the widely studied model organisms, sense external chemical cues and perform relative chemotaxis behaviors through its simple chemosensory neuronal system. To study the mechanism underlying chemosensory behavior, a rapid and reliable method for quantitatively analyzing the worms' behaviors is essential. In this work, we demonstrated a microfluidic approach for investigating chemotaxis responses of worms to chemical gradients. The flow-based microfluidic chip was consisted of circular tree-like microchannels, which was able to generate eight flow streams containing stepwise chemical concentrations without the difference in flow velocity. Worms' upstream swimming into microchannels with various concentrations was monitored for quantitative analysis of the chemotaxis behavior. By using this microfluidic chip, the attractive and repellent responses of C. elegans to NaCl were successfully quantified within several minutes. The results demonstrated the wild type-like repellent responses and severely impaired attractive responses in grk-2 mutant animals with defects in calcium influx. In addition, the chemotaxis analysis of the third stage larvae revealed that its gustatory response was different from that in the adult stage. Thus, our microfluidic method provided a useful platform for studying the chemosensory behaviors of C. elegans and screening of chemosensation-related chemical drugs.
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70
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Kim M, Kim T. Crack-Photolithography for Membrane-Free Diffusion-Based Micro/Nanofluidic Devices. Anal Chem 2015; 87:11215-23. [DOI: 10.1021/acs.analchem.5b02028] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Minseok Kim
- Department of Mechanical Engineering, ‡Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Eonyang-eup, Ulsan, 689-798, Republic of Korea
| | - Taesung Kim
- Department of Mechanical Engineering, ‡Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Eonyang-eup, Ulsan, 689-798, Republic of Korea
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71
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Taylor AM, Menon S, Gupton SL. Passive microfluidic chamber for long-term imaging of axon guidance in response to soluble gradients. LAB ON A CHIP 2015; 15:2781-9. [PMID: 26000554 PMCID: PMC4485391 DOI: 10.1039/c5lc00503e] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Understanding how axons are guided to target locations within the brain is of fundamental importance for neuroscience, and is a widely studied area of research. Biologists have an unmet need for reliable and easily accessible methods that generate stable, soluble molecular gradients for the investigation of axon guidance. Here we developed a microfluidic device with contiguous media-filled compartments that uses gravity-driven flow to generate a stable and highly reproducible gradient within a viewing compartment only accessible to axons. This device uses high-resistance microgrooves to both direct the growth of axons into an isolated region and to generate a stable gradient within the fluidically isolated axon viewing compartment for over 22 h. Establishing a stable gradient relies on a simple and quick pipetting procedure with no external pump or tubing. Since the axons extend into the axonal compartment through aligned microgrooves, the analysis of turning is simplified. Further, the multiple microgrooves in parallel alignment serve to increase sample sizes, improving statistical analyses. We used this method to examine growth cone turning in response to the secreted axon guidance cue netrin-1. We report the novel finding that growth cones of embryonic mouse cortical axons exhibited attractive turning in the lower concentrations of netrin-1, but were repulsed when exposed to higher concentrations. We also performed immunocytochemistry in growth cones exposed to a netrin-1 gradient within the axon viewing compartment and show that netrin receptors associated with both attraction and repulsion, DCC and UNC5H, localized to these growth cones. Together, we developed an accessible gradient chamber for higher throughput axon guidance studies and demonstrated its capabilities.
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Affiliation(s)
- A. M. Taylor
- UNC/NCSU Joint Department of Biomedical Engineering, UNC-Chapel Hill, Campus Box 7575, Chapel Hill NC 27599-7575, USA
- UNC Neuroscience Center, USA
- Carolina Institute for Developmental Disabilities, USA
| | - S. Menon
- UNC Department of Cell Biology and Physiology, UNC-Chapel Hill, Campus Box 7545, Chapel Hill, NC 27599-7545, USA
| | - S. L. Gupton
- UNC Department of Cell Biology and Physiology, UNC-Chapel Hill, Campus Box 7545, Chapel Hill, NC 27599-7545, USA
- UNC Neuroscience Center, USA
- UNC Lineberger Comprehensive Cancer Center, USA
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72
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Nagy K, Sipos O, Valkai S, Gombai É, Hodula O, Kerényi Á, Ormos P, Galajda P. Microfluidic study of the chemotactic response of Escherichia coli to amino acids, signaling molecules and secondary metabolites. BIOMICROFLUIDICS 2015; 9:044105. [PMID: 26339306 PMCID: PMC4506296 DOI: 10.1063/1.4926981] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 07/02/2015] [Indexed: 05/08/2023]
Abstract
Quorum sensing and chemotaxis both affect bacterial behavior on the population level. Chemotaxis shapes the spatial distribution of cells, while quorum sensing realizes a cell-density dependent gene regulation. An interesting question is if these mechanisms interact on some level: Does quorum sensing, a density dependent process, affect cell density itself via chemotaxis? Since quorum sensing often spans across species, such a feedback mechanism may also exist between multiple species. We constructed a microfluidic platform to study these questions. A flow-free, stable linear chemical gradient is formed in our device within a few minutes that makes it suitable for sensitive testing of chemoeffectors: we showed that the amino acid lysine is a weak chemoattractant for Escherichia coli, while arginine is neutral. We studied the effect of quorum sensing signal molecules of Pseudomonas aeruginosa on E. coli chemotaxis. Our results show that N-(3-oxododecanoyl)-homoserine lactone (oxo-C12-HSL) and N-(butryl)-homoserine lactone (C4-HSL) are attractants. Furthermore, we tested the chemoeffector potential of pyocyanin and pyoverdine, secondary metabolites under a quorum sensing control. Pyocyanin is proved to be a weak attractant while pyoverdine are repellent. We demonstrated the usability of the device in co-culturing experiments, where we showed that various factors released by P. aeruginosa affect the dynamic spatial rearrangement of a neighboring E. coli population, while surface adhesion of the cells is also modulated.
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Affiliation(s)
- Krisztina Nagy
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences , Temesvari krt. 62, H-6726 Szeged, Hungary
| | - Orsolya Sipos
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences , Temesvari krt. 62, H-6726 Szeged, Hungary
| | - Sándor Valkai
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences , Temesvari krt. 62, H-6726 Szeged, Hungary
| | - Éva Gombai
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences , Temesvari krt. 62, H-6726 Szeged, Hungary
| | - Orsolya Hodula
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences , Temesvari krt. 62, H-6726 Szeged, Hungary
| | - Ádám Kerényi
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences , Temesvari krt. 62, H-6726 Szeged, Hungary
| | - Pál Ormos
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences , Temesvari krt. 62, H-6726 Szeged, Hungary
| | - Péter Galajda
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences , Temesvari krt. 62, H-6726 Szeged, Hungary
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73
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Zhuang J, Wright Carlsen R, Sitti M. pH-Taxis of Biohybrid Microsystems. Sci Rep 2015; 5:11403. [PMID: 26073316 PMCID: PMC4466791 DOI: 10.1038/srep11403] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 05/06/2015] [Indexed: 11/17/2022] Open
Abstract
The last decade has seen an increasing number of studies developing bacteria and other cell-integrated biohybrid microsystems. However, the highly stochastic motion of these microsystems severely limits their potential use. Here, we present a method that exploits the pH sensing of flagellated bacteria to realize robust drift control of multi-bacteria propelled microrobots. Under three specifically configured pH gradients, we demonstrate that the microrobots exhibit both unidirectional and bidirectional pH-tactic behaviors, which are also observed in free-swimming bacteria. From trajectory analysis, we find that the swimming direction and speed biases are two major factors that contribute to their tactic drift motion. The motion analysis of microrobots also sheds light on the propulsion dynamics of the flagellated bacteria as bioactuators. It is expected that similar driving mechanisms are shared among pH-taxis, chemotaxis, and thermotaxis. By identifying the mechanism that drives the tactic behavior of bacteria-propelled microsystems, this study opens up an avenue towards improving the control of biohybrid microsystems. Furthermore, assuming that it is possible to tune the preferred pH of bioactuators by genetic engineering, these biohybrid microsystems could potentially be applied to sense the pH gradient induced by cancerous cells in stagnant fluids inside human body and realize targeted drug delivery.
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Affiliation(s)
- Jiang Zhuang
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Rika Wright Carlsen
- 1] Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA [2] Department of Engineering, Robert Morris University, Pittsburgh, PA 15108, USA
| | - Metin Sitti
- 1] Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA [2] Max Planck Institute for Intelligent Systems, Stuttgart 70569, Germany
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74
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Zhang H, Lohcharoenkal W, Sun J, Li X, Wang L, Wu N, Rojanasakul Y, Liu Y. Microfluidic gradient device for studying mesothelial cell migration and the effect of chronic carbon nanotube exposure. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2015; 25:075010. [PMID: 26937070 PMCID: PMC4770811 DOI: 10.1088/0960-1317/25/7/075010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cell migration is one of the crucial steps in many physiological and pathological processes, including cancer development. Our recent studies have shown that carbon nanotubes (CNTs), similarly to asbestos, can induce accelerated cell growth and invasiveness that contribute to their mesothelioma pathogenicity. Malignant mesothelioma is a very aggressive tumor that develops from cells of the mesothelium, and is most commonly caused by exposure to asbestos. CNTs have a similar structure and mode of exposure to asbestos. This has raised a concern regarding the potential carcinogenicity of CNTs, especially in the pleural area which is a key target for asbestos-related diseases. In this paper, a static microfluidic gradient device was applied to study the migration of human pleural mesothelial cells which had been through a long-term exposure (4 months) to subcytotoxic concentration (0.02 μg cm-2) of single-walled CNTs (SWCNTs). Multiple migration signatures of these cells were investigated using the microfluidic gradient device for the first time. During the migration study, we observed that cell morphologies changed from flattened shapes to spindle shapes prior to their migration after their sensing of the chemical gradient. The migration of chronically SWCNT-exposed mesothelial cells was evaluated under different fetal bovine serum (FBS) concentration gradients, and the migration speeds and number of migrating cells were extracted and compared. The results showed that chronically SWCNT-exposed mesothelial cells are more sensitive to the gradient compared to non-SWCNT-exposed cells. The method described here allows simultaneous detection of cell morphology and migration under chemical gradient conditions, and also allows for real-time monitoring of cell motility that resembles in vivo cell migration. This platform would be much needed for supporting the development of more physiologically relevant cell models for better assessment and characterization of the mesothelioma hazard posed by nanomaterials.
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Affiliation(s)
- Hanyuan Zhang
- Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA
| | - Warangkana Lohcharoenkal
- Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506, USA
| | - Jianbo Sun
- Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA
| | - Xiang Li
- Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA
| | - Liying Wang
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
| | - Nianqiang Wu
- Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506, USA
| | - Yon Rojanasakul
- Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506, USA
| | - Yuxin Liu
- Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA
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75
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Li D, Choi H, Cho S, Jeong S, Jin Z, Lee C, Ko SY, Park JO, Park S. A hybrid actuated microrobot using an electromagnetic field and flagellated bacteria for tumor-targeting therapy. Biotechnol Bioeng 2015; 112:1623-31. [DOI: 10.1002/bit.25555] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 01/09/2015] [Accepted: 01/18/2015] [Indexed: 12/28/2022]
Affiliation(s)
- Donghai Li
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
| | - Hyunchul Choi
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
| | - Sunghoon Cho
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
| | - Semi Jeong
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
| | - Zhen Jin
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
| | - Cheong Lee
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
| | - Seong Young Ko
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
| | - Jong-Oh Park
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
| | - Sukho Park
- School of Mechanical Engineering; Chonnam National University; Gwangju 500-757 Republic of Korea
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76
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Vogus DR, Mansard V, Rapp MV, Squires TM. Measuring concentration fields in microfluidic channels in situ with a Fabry-Perot interferometer. LAB ON A CHIP 2015; 15:1689-1696. [PMID: 25661262 DOI: 10.1039/c5lc00095e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recent advancements in microfluidic technology have allowed for the generation and control of complex chemical gradients; however, few general techniques can measure these spatio-temporal concentration profiles without fluorescent labeling. Here we describe a Fabry-Perot interferometric technique, capable of measuring concentration profiles in situ, without any chemical label, by tracking Fringes of Equal Chromatic Order (FECO). The technique has a sensitivity of 10(-5) RIU, which can be used to track local solute changes of ~0.05% (w/w). The technique is spatially resolved (1 μm) and easily measures evolving concentration fields with ~20 Hz rate. Here, we demonstrate by measuring the binary diffusion coefficients of various solutes and solvents (and their concentration-dependence) in both free solution and in polyethylene glycol diacrylate (PEG-DA) hydrogels.
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Affiliation(s)
- Douglas R Vogus
- Department of Chemical Engineering University of California, Santa Barbara, USA.
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77
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Kim H, Ali J, Phuyal K, Park S, Kim MJ. Investigation of bacterial chemotaxis using a simple three-point microfluidic system. BIOCHIP JOURNAL 2015. [DOI: 10.1007/s13206-014-9107-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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78
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Wang X, Atencia J, Ford RM. Quantitative analysis of chemotaxis towards toluene by Pseudomonas putida in a convection-free microfluidic device. Biotechnol Bioeng 2015; 112:896-904. [PMID: 25408100 DOI: 10.1002/bit.25497] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 11/01/2014] [Accepted: 11/12/2014] [Indexed: 01/06/2023]
Abstract
Chemotaxis has been shown to be beneficial for the migration of soil-inhabiting bacteria towards industrial chemical pollutants, which they degrade. Many studies have demonstrated the importance of this microbial property under various circumstances; however, few quantitative analyses have been undertaken to measure the two essential parameters that characterize the chemotaxis of bioremediation bacteria: the chemotactic sensitivity coefficient χ(0) and the chemotactic receptor constant K(c). The main challenge to determine these parameters is that χ(0) and K(c) are coupled together in non-linear mathematical models used to evaluate them. In this study we developed a method to accurately measure these parameters for Pseudomonas putida in the presence of toluene, an important pollutant in groundwater contamination. Our approach uses a multilayer microfluidic device to expose bacteria to a convection-free linear chemical gradient of toluene that is stable over time. The bacterial distribution within the gradient is measured in terms of fluorescence intensity, and is then used to fit the parameters Kc and χ(0) with mathematical models. Critically, bacterial distributions under chemical gradients at two different concentrations were used to solve for both parameters independently. To validate the approach, the chemotaxis parameters of Escherichia coli strains towards α-methylaspartate were experimentally derived and were found to be consistent with published results from related work.
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Affiliation(s)
- Xiaopu Wang
- Departmentof Chemical Engineering, School of Engineering Applied Science, University of Virginia, Charlottesville, Virginia, 22904
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79
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Somaweera H, Haputhanthri SO, Ibraguimov A, Pappas D. On-chip gradient generation in 256 microfluidic cell cultures: simulation and experimental validation. Analyst 2015; 140:5029-38. [DOI: 10.1039/c5an00481k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A microfluidic diffusion diluter was used to create a stable concentration gradient for dose response studies.
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Affiliation(s)
- Himali Somaweera
- Department of Chemistry and Biochemistry
- Texas Tech University
- Lubbock
- USA
| | | | - Akif Ibraguimov
- Department of Mathematics and Statistics
- Texas Tech University
- Lubbock
- USA
| | - Dimitri Pappas
- Department of Chemistry and Biochemistry
- Texas Tech University
- Lubbock
- USA
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80
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Abstract
Microfluidics has significantly contributed to the expansion of the frontiers of microbial ecology over the past decade by allowing researchers to observe the behaviors of microbes in highly controlled microenvironments, across scales from a single cell to mixed communities. Spatially and temporally varying distributions of organisms and chemical cues that mimic natural microbial habitats can now be established by exploiting physics at the micrometer scale and by incorporating structures with specific geometries and materials. In this article, we review applications of microfluidics that have resulted in insightful discoveries on fundamental aspects of microbial life, ranging from growth and sensing to cell-cell interactions and population dynamics. We anticipate that this flexible multidisciplinary technology will continue to facilitate discoveries regarding the ecology of microorganisms and help uncover strategies to control microbial processes such as biofilm formation and antibiotic resistance.
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Affiliation(s)
- Roberto Rusconi
- Ralph M. Parsons Laboratory, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; , ,
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81
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Shen C, Xu P, Huang Z, Cai D, Liu SJ, Du W. Bacterial chemotaxis on SlipChip. LAB ON A CHIP 2014; 14:3074-80. [PMID: 24968180 DOI: 10.1039/c4lc00213j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This paper describes a simple and reusable microfluidic SlipChip device for studying bacterial chemotaxis based on free interface diffusion. The device consists of two glass plates with reconfigurable microwells and ducts, which can set up 20 parallel chemotaxis units as duplicates. In each unit, three nanoliter microwells and connecting ducts were assembled for pipette loading of a chemoeffector solution, bacterial suspension, and 1X PBS buffer solution. By a simple slipping operation, three microwells were disconnected from other units and interconnected by the ducts, which allowed the formation of diffusion concentration gradients of the chemoeffector for inducing cell migration from the cell microwell towards the other two microwells. The migration of cells in the microwells was monitored and accurately counted to evaluate chemotaxis. Moreover, the migrated cells were easily collected by pipetting for further studies after a slip step to reconnect the chemoeffector microwells. The performance of the device was characterized by comparing chemotaxis of two Escherichia coli species, using aspartic acid as the attractant and nitrate sulfate as the repellent. It also enables the separation of bacterial species from a mixture, based on the difference of chemotactic abilities, and collection of the cells with strong chemotactic phenomena for further studies off the chip.
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Affiliation(s)
- Chaohua Shen
- Department of Chemistry, Renmin University of China, 100872 Beijing, China
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82
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Chung HH, Chan CK, Khire TS, Marsh GA, Clark A, Waugh RE, McGrath JL. Highly permeable silicon membranes for shear free chemotaxis and rapid cell labeling. LAB ON A CHIP 2014; 14:2456-68. [PMID: 24850320 PMCID: PMC4540053 DOI: 10.1039/c4lc00326h] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Microfluidic systems are powerful tools for cell biology studies because they enable the precise addition and removal of solutes in small volumes. However, the fluid forces inherent in the use of microfluidics for cell cultures are sometimes undesirable. An important example is chemotaxis systems where fluid flow creates well-defined and steady chemotactic gradients but also pushes cells downstream. Here we demonstrate a chemotaxis system in which two chambers are separated by a molecularly thin (15 nm), transparent, and nanoporous silicon membrane. One chamber is a microfluidic channel that carries a flow-generated gradient while the other chamber is a shear-free environment for cell observation. The molecularly thin membranes provide effectively no resistance to molecular diffusion between the two chambers, making them ideal elements for creating flow-free chambers in microfluidic systems. Analytical and computational flow models that account for membrane and chamber geometry, predict shear reduction of more than five orders of magnitude. This prediction is confirmed by observing the pure diffusion of nanoparticles in the cell-hosting chamber despite high input flow (Q = 10 μL min(-1); vavg ~ 45 mm min(-1)) in the flow chamber only 15 nm away. Using total internal reflection fluorescence (TIRF) microscopy, we show that a flow-generated molecular gradient will pass through the membrane into the quiescent cell chamber. Finally we demonstrate that our device allows us to expose migrating neutrophils to a chemotactic gradient or fluorescent label without any influence from flow.
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Affiliation(s)
- Henry H Chung
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA.
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83
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Xu H, Ferreira MM, Heilshorn SC. Small-molecule axon-polarization studies enabled by a shear-free microfluidic gradient generator. LAB ON A CHIP 2014; 14:2047-56. [PMID: 24781157 PMCID: PMC4528973 DOI: 10.1039/c4lc00162a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A deep understanding of the mechanisms behind neurite polarization and axon path-finding is important for interpreting how the human body guides neurite growth during development and response to injury. Further, it is of great clinical importance to identify diffusible chemical cues that promote neurite regeneration for nervous tissue repair. Despite the fast development of various types of concentration gradient generators, it has been challenging to fabricate neuron-friendly (i.e. shear-free and biocompatible for neuron growth and maturation) devices to create stable gradients, particularly for fast diffusing small molecules, which typically require high flow and shear rates. Here we present a finite element analysis for a polydimethylsiloxane/polyethylene glycol diacrylate (PDMS/PEG-DA) based gradient generator, describe the microfabrication process, and validate its use for neuronal axon polarization studies. This device provides a totally shear-free, biocompatible microenvironment with a linear and stable concentration gradient of small molecules such as forskolin. The gradient profile in this device can be customized by changing the composition or width of the PEG-DA barriers during direct UV photo-patterning within a permanently bonded PDMS device. Primary rat cortical neurons (embryonic E18) exposed to soluble forskolin gradients for 72 h exhibited statistically significant polarization and guidance of their axons. This device provides a useful platform for both chemotaxis and directional guidance studies, particularly for shear sensitive and non-adhesive cell cultures, while allowing fast new device design prototyping at a low cost.
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Affiliation(s)
- Hui Xu
- Department of Materials Science and Engineering, Stanford Cardiovascular Institute, Stanford University, 476 Lomita Mall, McCullough Building, Stanford, CA 94305-4045, USA.
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84
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Zhuang J, Wei G, Wright Carlsen R, Edwards MR, Marculescu R, Bogdan P, Sitti M. Analytical modeling and experimental characterization of chemotaxis in Serratia marcescens. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:052704. [PMID: 25353826 DOI: 10.1103/physreve.89.052704] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Indexed: 06/04/2023]
Abstract
This paper presents a modeling and experimental framework to characterize the chemotaxis of Serratia marcescens (S. marcescens) relying on two-dimensional and three-dimensional tracking of individual bacteria. Previous studies mainly characterized bacterial chemotaxis based on population density analysis. Instead, this study focuses on single-cell tracking and measuring the chemotactic drift velocity V(C) from the biased tumble rate of individual bacteria on exposure to a concentration gradient of l-aspartate. The chemotactic response of S. marcescens is quantified over a range of concentration gradients (10^{-3} to 5 mM/mm) and average concentrations (0.5 × 10(-3) to 2.5 mM). Through the analysis of a large number of bacterial swimming trajectories, the tumble rate is found to have a significant bias with respect to the swimming direction. We also verify the relative gradient sensing mechanism in the chemotaxis of S. marcescens by measuring the change of V(C) with the average concentration and the gradient. The applied full pathway model with fitted parameters matches the experimental data. Finally, we show that our measurements based on individual bacteria lead to the determination of the motility coefficient μ (7.25 × 10(-6) cm(2)/s) of a population. The experimental characterization and simulation results for the chemotaxis of this bacterial species contribute towards using S. marcescens in chemically controlled biohybrid systems.
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Affiliation(s)
- Jiang Zhuang
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Guopeng Wei
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Rika Wright Carlsen
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Matthew R Edwards
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Radu Marculescu
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Paul Bogdan
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA
| | - Metin Sitti
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA and Max-Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
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85
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Somaweera H, Ibragimov A, Pappas D. Generation of a chemical gradient across an array of 256 cell cultures in a single chip. Analyst 2014; 138:5566-71. [PMID: 23939026 DOI: 10.1039/c3an00946g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A microfluidic diffusion diluter to create stable chemical gradients across an array of cell cultures was demonstrated. The device enabled concentration based studies to be conducted at 256 different concentrations across individual, low shear cell cultures. A gradient of staurosporine on cells stained with Mitotracker Deep Red (MTDR) showed a concentration-based effect on cell apoptosis across the cell culture array.
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Affiliation(s)
- Himali Somaweera
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA.
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86
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Shao Y, Fu J. Integrated micro/nanoengineered functional biomaterials for cell mechanics and mechanobiology: a materials perspective. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:1494-533. [PMID: 24339188 PMCID: PMC4076293 DOI: 10.1002/adma.201304431] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/11/2013] [Indexed: 04/14/2023]
Abstract
The rapid development of micro/nanoengineered functional biomaterials in the last two decades has empowered materials scientists and bioengineers to precisely control different aspects of the in vitro cell microenvironment. Following a philosophy of reductionism, many studies using synthetic functional biomaterials have revealed instructive roles of individual extracellular biophysical and biochemical cues in regulating cellular behaviors. Development of integrated micro/nanoengineered functional biomaterials to study complex and emergent biological phenomena has also thrived rapidly in recent years, revealing adaptive and integrated cellular behaviors closely relevant to human physiological and pathological conditions. Working at the interface between materials science and engineering, biology, and medicine, we are now at the beginning of a great exploration using micro/nanoengineered functional biomaterials for both fundamental biology study and clinical and biomedical applications such as regenerative medicine and drug screening. In this review, an overview of state of the art micro/nanoengineered functional biomaterials that can control precisely individual aspects of cell-microenvironment interactions is presented and they are highlighted them as well-controlled platforms for mechanistic studies of mechano-sensitive and -responsive cellular behaviors and integrative biology research. The recent exciting trend where micro/nanoengineered biomaterials are integrated into miniaturized biological and biomimetic systems for dynamic multiparametric microenvironmental control of emergent and integrated cellular behaviors is also discussed. The impact of integrated micro/nanoengineered functional biomaterials for future in vitro studies of regenerative medicine, cell biology, as well as human development and disease models are discussed.
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Affiliation(s)
- Yue Shao
- Integrated Biosystems and Biomechanics Laboratory, Department of Mechanical Engineering, University of Michigan, Ann Arbor, 48109 (USA)
| | - Jianping Fu
- Integrated Biosystems and Biomechanics Laboratory, Department of Mechanical Engineering, University of Michigan, Ann Arbor, 48109 (USA). Department of Biomedical Engineering, University of Michigan, Ann Arbor, 48109 (USA)
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87
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McLaughlin LM, Xu H, Carden SE, Fisher S, Reyes M, Heilshorn SC, Monack DM. A microfluidic-based genetic screen to identify microbial virulence factors that inhibit dendritic cell migration. Integr Biol (Camb) 2014; 6:438-49. [PMID: 24599496 DOI: 10.1039/c3ib40177d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Microbial pathogens are able to modulate host cells and evade the immune system by multiple mechanisms. For example, Salmonella injects effector proteins into host cells and evades the host immune system in part by inhibiting dendritic cell (DC) migration. The identification of microbial factors that modulate normal host functions should lead to the development of new classes of therapeutics that target these pathways. Current screening methods to identify either host or pathogen genes involved in modulating migration towards a chemical signal are limited because they do not employ stable, precisely controlled chemical gradients. Here, we develop a positive selection microfluidic-based genetic screen that allows us to identify Salmonella virulence factors that manipulate DC migration within stable, linear chemokine gradients. Our screen identified 7 Salmonella effectors (SseF, SifA, SspH2, SlrP, PipB2, SpiC and SseI) that inhibit DC chemotaxis toward CCL19. This method is widely applicable for identifying novel microbial factors that influence normal host cell chemotaxis as well as revealing new mammalian genes involved in directed cell migration.
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88
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Wang Z, Lee I, Jeon TJ, Kim SM. Micro-/nanofluidic device for tunable generation of a concentration gradient: application to Caenorhabditis elegans chemotaxis. Anal Bioanal Chem 2014; 406:2679-86. [DOI: 10.1007/s00216-014-7663-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/22/2014] [Accepted: 01/23/2014] [Indexed: 12/24/2022]
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89
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Swimming characterization of Serratia marcescens for bio-hybrid micro-robotics. JOURNAL OF MICRO-BIO ROBOTICS 2014. [DOI: 10.1007/s12213-014-0072-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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90
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Hwang H, Kim EK, Park J, Suh PG, Cho YK. RhoA and Rac1 play independent roles in lysophosphatidic acid-induced ovarian cancer chemotaxis. Integr Biol (Camb) 2014; 6:267-76. [PMID: 24469268 DOI: 10.1039/c3ib40183a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Lysophosphatidic acid (LPA), which is a bioactive phospholipid existing at high level in ascites and plasma of ovarian cancer patients, is known to be involved in cell survival, proliferation, adhesion, and migration. Small guanosine triphosphatases (GTPases) such as RhoA and Rac1 are intracellular signaling molecules which affect morphology and chemotactic behavior of cells. In this research, we first investigated roles of RhoA and Rac1 in the LPA-induced chemotaxis of SKOV3 human ovarian cancer cells using a multilevel microfluidic platform. The multilevel microfluidic device was fabricated by a rapid prototyping method based on soft lithography using multi-layered adhesive tapes. This platform allows us to conduct the on-chip chemotaxis assays in conventional biology laboratories without any huge and expensive equipment for fabrication and fluidic manipulation. Based on image-based analysis of single cell trajectories in the microfluidic device, the chemotaxis of SKOV3 cells could be quantitatively analyzed in two independent parameters-migration speed and directional persistence. Inhibition of the RhoA/ROCK pathways reduced the directional persistence, not the migration speed, of the cells, while only the migration speed was decreased when the activity of Rac1/PAK pathways was suppressed. These results suggest that RhoA and Rac1 signaling pathways potentially play independent roles in the chemotactic migration of SKOV3 ovarian cancer cells in the linear and stable LPA concentration gradient. Our microfluidic platform would provide a rapid, low cost, easy-to-use, and versatile way for research of cancer cell migration which is crucial for tumor metastasis.
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Affiliation(s)
- Hyundoo Hwang
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea.
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91
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The Migration of Cancer Cells in Gradually Varying Chemical Gradients and Mechanical Constraints. MICROMACHINES 2014. [DOI: 10.3390/mi5010013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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92
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Sip CG, Bhattacharjee N, Folch A. Microfluidic transwell inserts for generation of tissue culture-friendly gradients in well plates. LAB ON A CHIP 2014; 14:302-14. [PMID: 24225908 PMCID: PMC4362725 DOI: 10.1039/c3lc51052b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Gradients of biochemical molecules play a key role in many physiological processes such as axon growth, tissue morphogenesis, and trans-epithelium nutrient transport, as well as in pathophysiological phenomena such as wound healing, immune response, bacterial invasion, and cancer metastasis. In this paper, we report a microfluidic transwell insert for generating quantifiable concentration gradients in a user-friendly and modular format that is compatible with conventional cell cultures and with tissue explant cultures. The device is simply inserted into a standard 6-well plate, where it hangs self-supported at a distance of ~250 μm above the cell culture surface. The gradient is created by small microflows from the device, through an integrated track-etched porous membrane, into the cell culture well. The microfluidic transwell can deliver stable, quantifiable gradients over a large area with extremely low fluid shear stress to dissociated cells or tissue explants cultured independently on the surface of a 6-well plate. We used finite-element modeling to describe the porous membrane flow and molecular transport and to predict gradients generated by the device. Using the device, we applied a gradient of the chemotactic peptide N-formyl-met-leu-phe (fMLP) to a large population of HL-60 cells (a neutrophil cell line) and directly observed the migration with time-lapse microscopy. On quantification of the chemotactic response with an automated tracking algorithm, we found 74% of the cells moving towards the gradient. Additionally, the modular design and low fluid shear stress made it possible to apply gradients of growth factors and second messengers to mouse retinal explant cultures. With a simplified interface and well-defined gradients, the microfluidic transwell device has potential for broad applications to gradient-sensing biology.
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Affiliation(s)
- Christopher G Sip
- Bioengineering, University of Washington, William H. Foege Building, 1705 NE Pacific St. Campus Box 355061, Seattle, Washington, USA.
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93
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Hamon M, Hong JW. New tools and new biology: recent miniaturized systems for molecular and cellular biology. Mol Cells 2013; 36:485-506. [PMID: 24305843 PMCID: PMC3887968 DOI: 10.1007/s10059-013-0333-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 11/14/2013] [Indexed: 01/09/2023] Open
Abstract
Recent advances in applied physics and chemistry have led to the development of novel microfluidic systems. Microfluidic systems allow minute amounts of reagents to be processed using μm-scale channels and offer several advantages over conventional analytical devices for use in biological sciences: faster, more accurate and more reproducible analytical performance, reduced cell and reagent consumption, portability, and integration of functional components in a single chip. In this review, we introduce how microfluidics has been applied to biological sciences. We first present an overview of the fabrication of microfluidic systems and describe the distinct technologies available for biological research. We then present examples of microsystems used in biological sciences, focusing on applications in molecular and cellular biology.
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Affiliation(s)
- Morgan Hamon
- Materials Research and Education Center, Department of Mechanical Engineering, Auburn University, Auburn, AL 36849,
USA
| | - Jong Wook Hong
- Materials Research and Education Center, Department of Mechanical Engineering, Auburn University, Auburn, AL 36849,
USA
- College of Pharmacy, Seoul National University, Seoul 151-741,
Korea
- Department of Bionano Engineering, Hanyang University, Ansan 426-791,
Korea
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94
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Park D, Park SJ, Cho S, Lee Y, Lee YK, Min JJ, Park BJ, Ko SY, Park JO, Park S. Motility analysis of bacteria-based microrobot (bacteriobot) using chemical gradient microchamber. Biotechnol Bioeng 2013; 111:134-43. [DOI: 10.1002/bit.25007] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 07/08/2013] [Accepted: 07/15/2013] [Indexed: 01/04/2023]
Affiliation(s)
- Daechul Park
- School of Mechanical Systems Engineering; Chonnam National University; Gwangju 500-757 Korea
| | - Sung Jun Park
- School of Mechanical Systems Engineering; Chonnam National University; Gwangju 500-757 Korea
| | - Sunghoon Cho
- School of Mechanical Systems Engineering; Chonnam National University; Gwangju 500-757 Korea
| | - Yeonkyung Lee
- School of Mechanical Systems Engineering; Chonnam National University; Gwangju 500-757 Korea
| | - Yu Kyung Lee
- School of Mechanical Systems Engineering; Chonnam National University; Gwangju 500-757 Korea
| | - Jung-Joon Min
- Department of Nuclear Medicine; Chonnam National University Medical School; Gwangju Korea
| | - Bang Ju Park
- College of BioNano Technology; Gachon University; Gyeonggi-do Korea
| | - Seong Young Ko
- School of Mechanical Systems Engineering; Chonnam National University; Gwangju 500-757 Korea
| | - Jong-Oh Park
- School of Mechanical Systems Engineering; Chonnam National University; Gwangju 500-757 Korea
| | - Sukho Park
- School of Mechanical Systems Engineering; Chonnam National University; Gwangju 500-757 Korea
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95
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Tandon N, Marolt D, Cimetta E, Vunjak-Novakovic G. Bioreactor engineering of stem cell environments. Biotechnol Adv 2013; 31:1020-31. [PMID: 23531529 DOI: 10.1016/j.biotechadv.2013.03.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Revised: 12/02/2012] [Accepted: 03/11/2013] [Indexed: 12/31/2022]
Abstract
Stem cells hold promise to revolutionize modern medicine by the development of new therapies, disease models and drug screening systems. Standard cell culture systems have limited biological relevance because they do not recapitulate the complex 3-dimensional interactions and biophysical cues that characterize the in vivo environment. In this review, we discuss the current advances in engineering stem cell environments using novel biomaterials and bioreactor technologies. We also reflect on the challenges the field is currently facing with regard to the translation of stem cell based therapies into the clinic.
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Affiliation(s)
- Nina Tandon
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
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96
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Xu H, Heilshorn SC. Microfluidic investigation of BDNF-enhanced neural stem cell chemotaxis in CXCL12 gradients. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:585-95. [PMID: 23109183 PMCID: PMC3984949 DOI: 10.1002/smll.201202208] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Indexed: 05/24/2023]
Abstract
In vivo studies have suggested that gradients of CXCL12 (aka stromal cell-derived factor 1α) may be critical for neural stem cell (NSC) migration during brain development and neural tissue regeneration. However, traditional in vitro chemotaxis tools are limited by unstable concentration gradients and the inability to decouple cell migration directionality and speed. These limitations have restricted the reproducible and quantitative analysis of neuronal migration, which is required for mechanism-based studies. Using a microfluidic gradient generator, nestin and Sox-2 positive human embryonic NSC chemotaxis is quantified within a linear and stable CXCL12 gradient. While untreated NSCs are not able to chemotax within CXCL12 gradients, pre-treatment of the cells with brain-derived neurotrophic factor (BDNF) results in significant chemotactic, directional migration. BDNF pre-treatment has no effect on cell migration speed, which averages about 1 μm min(-1). Quantitative analysis determines that CXCL12 concentrations above 9.0 nM are above the minimum activation threshold, while concentrations below 14.7 nM are below the saturation threshold. Interestingly, although inhibitor studies with AMD 3100 revealed that CXCL12 chemotaxis requires receptor CXCR4 activation, BDNF pre-treatment is found to have no profound effects on the mRNA levels or surface presentation of CXCR4 or the putative CXCR7 scavenger receptor. The microfluidic study of NSC migration within stable chemokine concentration profiles provides quantitative analysis as well as new insight into the migratory mechanism underlying BDNF-induced chemotaxis towards CXCL12.
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97
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Cimetta E, Sirabella D, Yeager K, Davidson K, Simon J, Moon RT, Vunjak-Novakovic G. Microfluidic bioreactor for dynamic regulation of early mesodermal commitment in human pluripotent stem cells. LAB ON A CHIP 2013; 13:355-64. [PMID: 23232509 PMCID: PMC3535552 DOI: 10.1039/c2lc40836h] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
During development and regeneration, tissues emerge from coordinated sequences of stem cell renewal, specialization and assembly that are orchestrated by cascades of regulatory signals. The complex and dynamic in vivo milieu cannot be replicated using standard in vitro techniques. Microscale technologies now offer potential for conducting highly controllable and sophisticated experiments at biologically relevant scales, with real-time insights into cellular responses. We developed a microbioreactor providing time sequences of space-resolved gradients of multiple molecular factors in three-dimensional (3D) cell culture settings, along with a versatile, high-throughput operation and imaging compatibility. A single microbioreactor yields up to 120 data points, corresponding to 15 replicates of a gradient with 8 concentration levels. Embryoid bodies (EBs) obtained from human embryonic and induced pluripotent stem cells (hESC, hiPSC) were exposed to concentration gradients of Wnt3a, Activin A, BMP4 and their inhibitors, to get new insights into the early-stage fate specification and mesodermal lineage commitment. We were able to evaluate the initiation of mesodermal induction by measuring and correlating the gene expression profiles to the concentration gradients of mesoderm-inducing morphogens. We propose that the microbioreactor systems combining spatial and temporal gradients of molecular and physical factors to hESC and hiPSC cultures can form a basis for predictable in vitro models of development and disease.
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Affiliation(s)
- Elisa Cimetta
- Columbia University, Department of Biomedical Engineering, Vanderbilt Clinic, New York, NY 10032, USA.
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98
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Park ES, Difeo MA, Rand JM, Crane MM, Lu H. Sequentially pulsed fluid delivery to establish soluble gradients within a scalable microfluidic chamber array. BIOMICROFLUIDICS 2013; 7:11804. [PMID: 24403986 PMCID: PMC3555978 DOI: 10.1063/1.4774313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 12/17/2012] [Indexed: 05/23/2023]
Abstract
This work presents a microfluidic chamber array that generates soluble gradients using sequentially pulsed fluid delivery (SPFD). SPFD produces stable gradients by delivering flow pulses to either side of a chamber. The pulses on each side contain different signal concentrations, and they alternate in sequence, providing the driving force to establish a gradient via diffusion. The device, herein, is significant because it demonstrates the potential to simultaneously meet four important needs that can accelerate and enhance the study of cellular responses to signal gradients. These needs are (i) a scalable chamber array, (ii) low complexity fabrication, (iii) a non-shearing microenvironment, and (iv) gradients with low (near zero) background concentrations. The ability to meet all four needs distinguishes the SPFD device from flow-based and diffusion-based designs, which can only achieve a subset of such needs. Gradients are characterized using fluorescence measurements, which reveal the ability to change the curvature of concentration profiles by simple adjustments to pulsing sequence and flow rate. Preliminary experiments with MDA-MB-231 cancer cells demonstrate cell viability and indicate migrational and morphological responses to a fetal bovine serum gradient. Improved and expanded versions of this technology could form the basis of high-throughput screening tools to study cell migration, development, and cancer.
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Affiliation(s)
- Edward S Park
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Michael A Difeo
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Jacqueline M Rand
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Matthew M Crane
- The Parker H. Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA ; Interdisciplinary Program of Bioengineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA ; The Parker H. Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA ; Interdisciplinary Program of Bioengineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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99
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Wu X, Xu C, Tripp RA, Huang YW, Zhao Y. Detection and differentiation of foodborne pathogenic bacteria in mung bean sprouts using field deployable label-free SERS devices. Analyst 2013; 138:3005-12. [DOI: 10.1039/c3an00186e] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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100
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Weibull E, Matsui S, Sakai M, Andersson Svahn H, Ohashi T. Microfluidic device for generating a stepwise concentration gradient on a microwell slide for cell analysis. BIOMICROFLUIDICS 2013; 7:64115. [PMID: 24396549 PMCID: PMC3874052 DOI: 10.1063/1.4846435] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 11/28/2013] [Indexed: 05/04/2023]
Abstract
Understanding biomolecular gradients and their role in biological processes is essential for fully comprehending the underlying mechanisms of cells in living tissue. Conventional in vitro gradient-generating methods are unpredictable and difficult to characterize, owing to temporal and spatial fluctuations. The field of microfluidics enables complex user-defined gradients to be generated based on a detailed understanding of fluidic behavior at the μm-scale. By using microfluidic gradients created by flow, it is possible to develop rapid and dynamic stepwise concentration gradients. However, cells exposed to stepwise gradients can be perturbed by signals from neighboring cells exposed to another concentration. Hence, there is a need for a device that generates a stepwise gradient at discrete and isolated locations. Here, we present a microfluidic device for generating a stepwise concentration gradient, which utilizes a microwell slide's pre-defined compartmentalized structure to physically separate different reagent concentrations. The gradient was generated due to flow resistance in the microchannel configuration of the device, which was designed using hydraulic analogy and theoretically verified by computational fluidic dynamics simulations. The device had two reagent channels and two dilutant channels, leading to eight chambers, each containing 4 microwells. A dose-dependency assay was performed using bovine aortic endothelial cells treated with saponin. High reproducibility between experiments was confirmed by evaluating the number of living cells in a live-dead assay. Our device generates a fully mixed fluid profile using a simple microchannel configuration and could be used in various gradient studies, e.g., screening for cytostatics or antibiotics.
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Affiliation(s)
- Emilie Weibull
- Division of Proteomics and Nanobiotechnology, Science for Life Laboratory, KTH-Royal Institute of Technology, 171 65 Stockholm, Sweden
| | - Shunsuke Matsui
- Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Manabu Sakai
- Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Helene Andersson Svahn
- Division of Proteomics and Nanobiotechnology, Science for Life Laboratory, KTH-Royal Institute of Technology, 171 65 Stockholm, Sweden
| | - Toshiro Ohashi
- Faculty of Engineering, Hokkaido University, Sapporo Hokkaido 060-8628, Japan
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