| 1. |
- Ahemaiti, Aikeremu, 1984, et al.
(författare)
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A multifunctional pipette for localized drug administration to brain slices
- 2013
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Ingår i: Journal of Neuroscience Methods. - : Elsevier BV. - 0165-0270 .- 1872-678X. ; 219:2, s. 292-296
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a superfusion method utilizing an open-volume microfluidic device for administration of pharmacologically active substances to selected areas in brain slices with high spatio-temporal resolution. The method consists of a hydrodynamically confined flow of the active chemical compound, which locally stimulates neurons in brain slices, applied in conjunction with electrophysiological recording techniques to analyze the response. The microfluidic device, which is a novel free-standing multifunctional pipette, allows diverse superfusion experiments, such as testing the effects of different concentrations of drugs or drug candidates on neurons in different cell layers with high positional accuracy, affecting only a small number of cells. We demonstrate herein the use of the method with electrophysiological recordings of pyramidal cells in hippocampal and prefrontal cortex brain slices from rats, determine the dependence of electric responses on the distance of the superfusion device from the recording site, document a multifold gain in solution exchange time as compared to whole slice perfusion, and show that the device is able to store and deliver up to four solutions in a series. Localized solution delivery by means of open-volume microfluidic technology also reduces reagent consumption and tissue culture expenses significantly, while allowing more data to be collected from a single tissue slice, thus reducing the number of laboratory animals to be sacrificed for a study. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
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| 3. |
- Ainla, Alar, 1982, et al.
(författare)
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A Microfluidic Pipette for Single-Cell Pharmacology
- 2010
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 82:11, s. 4529-4536
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Tidskriftsartikel (refereegranskat)abstract
- We report on a free-standing microfluidic pipette made in poly(dimethylsiloxane) having a circulating liquid tip that generates a self-con-fining volume in front of the outlet channels. The method is flexible and scalable as the geometry and the size of the recirculation zone is defined by pressure, channel number, and geometry. The pipette is capable of carrying out a variety of complex fluid processing operations, such as mixing, multiplexing, or gradient generation at selected cells in cell and tissue cultures. Using an uptake assay, we show that it is possible to generate dose response curves in situ from adherent Chinese hamster ovary cells expressing proton-activated human transient receptor potential vanilloid (hTRPV1) receptors. Using confined superfusion and cell stimulation, we could activate hTRPV1 receptors in single cells, measure the response by a patch-clamp pipette, and induce membrane bleb formation by exposing selected groups of cells to formaldehyde/dithiothreitol-containing solutions, respectively. In short, the microfluidic pipette allows for complex, contamination-free multiple-compound delivery for pharmacological screening of intact adherent cells.
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| 4. |
- Ainla, Alar, 1982, et al.
(författare)
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A multi-purpose microfluidic pipette for single-cell analysis
- 2010
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Ingår i: 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2010, MicroTAS 2010; Groningen; Netherlands; 3 October 2010 through 7 October 2010. - 9781618390622 ; 2, s. 932-934
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Konferensbidrag (refereegranskat)abstract
- We report a multi-purpose microfluidic pipette, with a recirculating liquid tip. This device, made in poly(dimethylsiloxane), enables contamination-free manipulation and chemical stimulation of selected single cells in cell collectives or tissue slices. The pipette is capable of carrying out a variety of complex fluid processing functionalities, such as mixing, multiplexing, or gradient generation. The concept is flexible and scalable as the geometry and the size of the recirculation zone is defined by pressure, channel number, and geometry. We have applied the pipette in a fluorescence uptake assay, electrophysiology studies and for chemical induction of membrane protrusion from biological cells.
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| 5. |
- Ainla, Alar, 1982, et al.
(författare)
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A multifunctional pipette
- 2012
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Ingår i: Lab on a Chip - Miniaturisation for Chemistry and Biology. - : Royal Society of Chemistry (RSC). - 1473-0189 .- 1473-0197. ; 12:7, s. 1255-1261
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Tidskriftsartikel (refereegranskat)abstract
- Microfluidics has emerged as a powerful laboratory toolbox for biologists, allowing manipulation and analysis of processes at a cellular and sub-cellular level, through utilization of microfabricated features at size-scales relevant to that of a single cell. In the majority of microfluidic devices, sample processing and analysis occur within closed microchannels, imposing restrictions on sample preparation and use. We present an optimized non-contact open-volume microfluidic tool to overcome these and other restrictions, through the use of a hydrodynamically confined microflow pipette, serving as a multifunctional solution handling and dispensing tool. The geometries of the tool have been optimised for use in optical microscopy, with integrated solution reservoirs to reduce reagent use, contamination risks and cleaning requirements. Device performance was characterised using both epifluorescence and total internal reflection fluorescence (TIRF) microscopy, resulting in similar to 200 ms and similar to 130 ms exchange times at similar to 100 nm and similar to 30 mm distances to the surface respectively.
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| 6. |
- Ainla, Alar, 1982, et al.
(författare)
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Hydrodynamic Flow Confinement Technology in Microfluidic Perfusion Devices
- 2012
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Ingår i: Micromachines. - : MDPI AG. - 2072-666X. ; 3:2, s. 442-461
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Forskningsöversikt (refereegranskat)abstract
- Hydrodynamically confined flow device technology is a young research area with high practical application potential in surface processing, assay development, and in various areas of single cell research. Several variants have been developed, and most recently, theoretical and conceptual studies, as well as fully developed automated systems, were presented. In this article we review concepts, fabrication strategies, and application areas of hydrodynamically confined flow (HCF) devices.
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| 7. |
- Ainla, Alar, 1982, et al.
(författare)
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Lab on a Biomembrane
- 2014
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Ingår i: Biophysical Journal. - 0006-3495 .- 1542-0086. ; 106:2, s. 209A-209A
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Ainla, Alar, 1982, et al.
(författare)
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Lab on a Biomembrane: Rapid prototyping and manipulation of 2D fluidic lipid bilayers circuits
- 2013
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Lipid bilayer membranes are among the most ubiquitous structures in the living world, with intricate structural features and a multitude of biological functions. It is attractive to recreate these structures in the laboratory, as this allows mimicking and studying the properties of biomembranes and their constituents, and to specifically exploit the intrinsic two-dimensional fluidity. Even though diverse strategies for membrane fabrication have been reported, the development of related applications and technologies has been hindered by the unavailability of both versatile and simple methods. Here we report a rapid prototyping technology for two-dimensional fluidic devices, based on in-situ generated circuits of phospholipid films. In this "lab on a molecularly thin membrane'', various chemical and physical operations, such as writing, erasing, functionalization, and molecular transport, can be applied to user-defined regions of a membrane circuit. This concept is an enabling technology for research on molecular membranes and their technological use.
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| 9. |
- Ainla, Alar, 1982, et al.
(författare)
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Single-cell electroporation using a multifunctional pipette
- 2012
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Ingår i: Lab on a Chip - Miniaturisation for Chemistry and Biology. - : Royal Society of Chemistry (RSC). - 1473-0189 .- 1473-0197. ; 12:22, s. 4605-4609
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Tidskriftsartikel (refereegranskat)abstract
- We present here a novel platform combination, using a multifunctional pipette to individually electroporate single-cells and to locally deliver an analyte, while in their culture environment. We demonstrate a method to fabricate low-resistance metallic electrodes into a PDMS pipette, followed by characterization of its effectiveness, benefits and limits in comparison with an external carbon microelectrode.
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| 10. |
- Balasubramaniam, S., et al.
(författare)
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A review of experimental opportunities for molecular communication
- 2013
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Ingår i: Nano Communication Networks. - : Elsevier BV. - 1878-7789. ; 4:2, s. 43-52
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Tidskriftsartikel (refereegranskat)abstract
- The growth of nanotechnology has led to miniature devices that are able to perform limited functionalities in hard to access areas. Example nanodevice applications in the healthcare domain include early detection of harmful diseases. The current field of molecular communication is aiming to increase the functionalities of nanodevices, by enabling communication to be performed. Since its first introduction, communication researchers have been proposing various solutions that could possibly realize molecular communications (e.g., molecular diffusion and bacteria nanonetworks). These solutions have largely been limited to theoretical simulation modeling. However, to fully realize a future for real deployments and developments of molecular communication, a strong synergy will be required with molecular biologists. The aim of this paper is to create this link, and at the same time provide guidance for current molecular communication researchers of possible real developments of molecular communication based on the current state-of-the-art experimental work. In particular, we present a review on bacteria communication and membrane nanotubes, as well as neuronal networks. We also discuss possible applications in the future focusing in particular on Body Area NanoNetworks (BAN2). © 2013 Elsevier Ltd.
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