Nanofluidic Networks Based on Surfactant Membrane Technology

Karlsson, Anders; Karlsson, Mattias; Karlsson, Roger; Sott, Kristin; Lundqvist, Anders; Tokarz, Michal; Orwar, Owe

doi:10.1021/ac0340206

Cited by 52 publications

(56 citation statements)

References 26 publications

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“…In fact, the compression might be strong enough for even the largest DNA molecule to fit completely inside the detection volume, which would give a linear relation between the mean peak intensity and the number of base pairs. Given the membrane tension of Ϸ1 ϫ 10 Ϫ6 J͞m 2 in our system (15,21), Brochard-Wyart et al predict that the transition from the blob behavior (in an unperturbed channel) to the compressed globule occurs for a polymer size of Ϸ150 persistence lengths, or 22 kbp given that P ϭ 150 bp at our ionic strength. Thus, the theory predicts that the two smallest DNA sizes we have studied should attain a blob-like conformation in an unperturbed tube, with X174 and p⌬-DNA containing one and two blobs, respectively (Table 1), i.e., these coils are only slightly elongated.…”

Section: Resultsmentioning

confidence: 90%

“…The cross-linked gel acts as a salt bridge, preventing bulk solvent f low, but allowing electric current to pass. (EG & G Canada, Vaudreuil, Canada) and is described in detail elsewhere (15). The detector is coupled to a data acquisition card (NI PCI-6024E, National Instruments, Austin TX) on a personal computer running in-house-built LABVIEW 7.1 data collection software counting the number of incident photons with a bin size of 5 ms.…”

Section: Methodsmentioning

confidence: 99%

“…Such lipidbased networks can be prepared with designed connectivity, geometry, topology, and dimensionality, and their contents and surface properties can be controlled as described (15)(16)(17)(18)(19)(20)(21). These in vitro-fabricated networks are of the same amphiphilic and self-assembling nature as nanotubes found in vivo, and with similar dimensions regarding both radii (50-150 nm) (1) and lengths (up to tens of m).…”

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confidence: 99%

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Single-file electrophoretic transport and counting of individual DNA molecules in surfactant nanotubes

Tokarz

Åkerman

Olofsson

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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We demonstrate a complete nanotube electrophoresis system (nanotube radii in the range of 50 to 150 nm) based on lipid membranes, comprising DNA injection, single-molecule transport, and single-molecule detection. Using gel-capped electrodes, electrophoretic single-file transport of fluorescently labeled dsDNA molecules is observed inside nanotubes. The strong confinement to a channel of molecular dimensions ensures a detection efficiency close to unity and identification of DNA size from its linear relation to the integrated peak intensity. In addition to constituting a nanotechnological device for identification and quantification of single macromolecules or biopolymers, this system provides a method to study their conformational dynamics, reaction kinetics, and transport in cell-like environments.electrophoresis ͉ lipid ͉ conformation C ontrolled transport, interrogation, and manipulation of single molecules in integrated nanoscale devices would provide new tools for fundamental studies of molecular properties, development of ultrasensitive biochemical assays, and new models for studies of transport and reaction phenomena in confined biological systems. For example, it was recently shown that lipid bilayer nanotubes Ϸ50-200 nm in diameter are involved in mediated transport of water-soluble and membrane-bound components between cells (1). Such observations do not only raise important questions about transport mechanisms for macromolecules and organelles in spaces comparable to the size of the cargo itself, but also about how such strong confinement affects diffusion, conformation, and chemical reactions of enclosed molecules and particles (2-4). Furthermore, along with previous understanding of sorting and routing of individual molecules, e.g., in the Golgi-endoplasmic reticulum network (5, 6), these observations point out clearly that what has been an engineering dream for decades, i.e., to create manmade devices that can operate with single molecules in a controlled fashion, is a reality in biology and therefore can be a reality in the world of engineering provided that we procure sufficient knowledge and tools to emulate these systems. However, experimental systems for controlled confinement and transport of materials dissolved in fluids approaching the theoretical size limit, i.e., where the ratio of channel inner diameter and dimensions of the cargo are close to unity, have been difficult to make in combination with transport control. This difficulty is mainly because these systems have been fabricated by using solid-state materials and processing technologies used in the computer industry that are limited in terms of the smallest accessible length scales, topologies, materials properties, complexity of fabrication, and their necessary integration to large-scale instrumentation to drive fluid flow. Nonetheless, powerful micro͞nanofluidic protocols for polymer transport in solid-state nanochannels and pores (7-12) as well as in polydimethylsiloxane channels of a few micrometers in diameter (13, 14) have be...

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Section: Resultsmentioning

confidence: 90%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Single-file electrophoretic transport and counting of individual DNA molecules in surfactant nanotubes

Tokarz

Åkerman

Olofsson

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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“…Single-molecule transport and spectroscopy have been reported 66 , and fundamental properties and the dynamics of lipid nanotubes 38,42,67 , which have an important role in intercellular transport and communication 5 , have been investigated. Limitations come partly from the properties of the soft-matter materials used to build these networks and partly from restrictions on experimental conditions.…”

Section: Applications and Limitationsmentioning

confidence: 99%

Generation of phospholipid vesicle-nanotube networks and transport of molecules therein

et al. 2011

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We describe micromanipulation and microinjection procedures for the fabrication of soft-matter networks consisting of lipid bilayer nanotubes and surface-immobilized vesicles. these biomimetic membrane systems feature unique structural flexibility and expandability and, unlike solid-state microfluidic and nanofluidic devices prepared by top-down fabrication, they allow network designs with dynamic control over individual containers and interconnecting conduits. the fabrication is founded on self-assembly of phospholipid molecules, followed by micromanipulation operations, such as membrane electroporation and microinjection, to effect shape transformations of the membrane and create a series of interconnected compartments. size and geometry of the network can be chosen according to its desired function. Membrane composition is controlled mainly during the self-assembly step, whereas the interior contents of individual containers is defined through a sequence of microneedle injections. networks cannot be fabricated with other currently available methods of giant unilamellar vesicle preparation (large unilamellar vesicle fusion or electroformation). Described in detail are also three transport modes, which are suitable for moving water-soluble or membranebound small molecules, polymers, Dna, proteins and nanoparticles within the networks. the fabrication protocol requires ~90 min, provided all necessary preparations are made in advance. the transport studies require an additional 60-120 min, depending on the transport regime. 20,29 . Once a needle is inside a GUV, the bilayer tightly seals around the tip. The adhesion of the membrane is typically strong enough to allow the pulling of lipid material from the membrane, thereby instantly forming an open nanoconduit between the vesicle and the capillary. The flexible lipid nanotubes created in this way can be expanded at the needle-connected end by means of positive injection pressure, to an extent that a new vesicle is formed (Fig. 1, stage IV). Constant subsequent injection of fluid from the needle allows the 'daughter' vesicle to grow to a size appropriate for deposition onto the substrate (Fig. 1, stage V). Iteration of this pulling and vesiclegeneration process enables the building of whole networks of interconnected containers, in which size, geometry and individual contents can be controlled. If a new needle with different internal solution is used for the generation of each new vesicle, a network with differentiated contents can be created. The composition of the internal volume of each newly created vesicle is determined by the size ratio of mother and daughter vesicles 30 .As the nanoconduits are open on both ends and thus truly interconnect the individual containers, exchange of internal solution, and chemical compounds dissolved therein, is possible. Different regimes of exchange of matter have been investigated by us. In particular, the transport of small molecules and nanoparticles by diffusion [31][32][33] , by membrane tension-driven (Marangoni) flow 3...

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“…Our lab and other groups have developed concepts and protocols for producing nanoscale devices and networks based on spontaneous and forced shape transitions in lipid bilayer membranes or other soft materials (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). The networks consist of surface-immobilized vesicles (~5-50-µm diam) conjugated by nanotubes (50 -150-nm radius).…”

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confidence: 99%

Chemical Analysis in Nanoscale Surfactant Networks

Karlsson¹,

Ewing²,

Dommersnes³

et al. 2006

Anal. Chem.

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A lthough the "hard matter" physical sciences (e.g., microelectronics) and the "soft matter" biological sciences (e.g. cell biology and molecular biology) are two distinct areas of research, they are now progressively being combined to create new systems and devices with applications in analytical chemistry. Miniaturization is one of the important factors here: A major goal is to create devices that can operate with high sensitivity and resolution on length scales and time frames relevant to single-molecule studies. Using top-down strategies to fabricate ultrasmall structures is technologically challenging. Therefore, new bottom-up methods of nanoscale fabrication based on self-assembly and self-organization of biological or biomimetic materials are constantly being developed (1-6). The type of nanoscale engineering described in this article has, at least partly, been derived from our growing understanding of living cells, where many nanomechanical and chemical operations are based on controlled shape transitions in surfactant bilayer membranes that also carry proteins to support important functions. Biological cells have a staggering ability to parallel-process multiple chemical reactions and physical (e.g., transport) processes in nanometer-sized systems and to perform a great number of tasks based on single-molecule processes. Thus, nature has solved many engineering problems on small length scales and achieved truly nanoscale, complex chemical devices that can be used for computational, biophysical, synthetic, and analytical applications (7-11). The philosophy behind the work reviewed here is to produce human-made, biomimetic systems that imitate some key features of small biological systems with the overall goal of providing micro-and nanoscale devices that can perform complex chemical operations.

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Nanofluidic Networks Based on Surfactant Membrane Technology

Cited by 52 publications

References 26 publications

Single-file electrophoretic transport and counting of individual DNA molecules in surfactant nanotubes

Single-file electrophoretic transport and counting of individual DNA molecules in surfactant nanotubes

Generation of phospholipid vesicle-nanotube networks and transport of molecules therein

Chemical Analysis in Nanoscale Surfactant Networks

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