Direct-Write Patterning of Biomimetic Lipid Membranes In Situ with FluidFM

A platform for light-controlled formation of free-stranding lipid membranes

Journal of The Royal Society Interface ◽

10.1098/rsif.2019.0740 ◽

2020 ◽

Vol 17 (163) ◽

pp. 20190740 ◽

Cited By ~ 1

Author(s):

Nikolay V. Ryzhkov ◽

Ekaterina V. Skorb

Keyword(s):

Lipid Bilayers ◽

Lipid Membranes ◽

Science And Technology Studies ◽

Separation Distance ◽

Layer By Layer ◽

Net Charge ◽

Novel Approach ◽

Layer Deposition ◽

Transmembrane Channels

The engineering of artificial cells is one of the most significant scientific challenges. Thus, controlled fabrication and in situ monitoring of biomimetic nanoscale objects are among the central issues in current science and technology. Studies of transmembrane channels and cell mechanics often require the formation of lipid bilayers (LBs), their modification and their transfer to a particular place. We present here a novel approach for remotely controlled manipulation of LBs. Layer-by-layer deposition of polyethyleneimine and poly(sodium 4-styrenesulfonate) on a nanostructured TiO 2 photoanode was performed to obtain a surface with the desired net charge and to enhance photocatalytic performance. The LB was deposited on top of a multi-layer positive polymer cushion by the dispersion of negative vesicles. The separation distance between the electrostatically linked polyelectrolyte cushion and the LB can be adjusted by changing the environmental pH, as zwitter-ionic lipid molecules undergo pH-triggered charge-shifting. Protons were generated remotely by photoanodic water decomposition on the TiO 2 surface under 365 nm illumination. The resulting pH gradient was characterized by scanning vibrating electrode and scanning ion-selective electrode techniques. The light-induced reversible detachment of the LB from the polymer-cushioned photoactive substrate was found to correlate with suggested impedance models.

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Insights into IgM-mediated complement activation based on in situ structures of IgM-C1-C4b

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1901841116 ◽

2019 ◽

pp. 201901841 ◽

Cited By ~ 14

Author(s):

Thomas H. Sharp ◽

Aimee L. Boyle ◽

Christoph A. Diebolder ◽

Alexander Kros ◽

Abraham J. Koster ◽

...

Keyword(s):

Immune Responses ◽

Complement Activation ◽

Lipid Membranes ◽

Product Release ◽

Limiting Step ◽

Microbial Infections ◽

Life Threatening ◽

Normal Human ◽

Conformational Rearrangements

Antigen binding by serum Ig-M (IgM) protects against microbial infections and helps to prevent autoimmunity, but causes life-threatening diseases when mistargeted. How antigen-bound IgM activates complement-immune responses remains unclear. We present cryoelectron tomography structures of IgM, C1, and C4b complexes formed on antigen-bearing lipid membranes by normal human serum at 4 °C. The IgM-C1-C4b complexes revealed C4b product release as the temperature-limiting step in complement activation. Both IgM hexamers and pentamers adopted hexagonal, dome-shaped structures with Fab pairs, dimerized by hinge domains, bound to surface antigens that support a platform of Fc regions. C1 binds IgM through widely spread C1q-collagen helices, with C1r proteases pointing outward and C1s bending downward and interacting with surface-attached C4b, which further interacts with the adjacent IgM-Fab2and globular C1q-recognition unit. Based on these data, we present mechanistic models for antibody-mediated, C1q-transmitted activation of C1 and for C4b deposition, while further conformational rearrangements are required to form C3 convertases.

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Laser Direct Write and Gas Immersion Laser Doping Fabrication of SiC Diodes

MRS Proceedings ◽

10.1557/proc-815-j3.4 ◽

2004 ◽

Vol 815 ◽

Cited By ~ 2

Author(s):

Z. Tian ◽

N.R. Quick ◽

A. Kar

Keyword(s):

Ohmic Contacts ◽

Wafer Surface ◽

Direct Write ◽

Laser Doping ◽

Sensing Applications ◽

P Type ◽

Sic Wafer ◽

Laser Direct Write ◽

Defect Densities

AbstractLaboratory prototype SiC diodes are fabricated using a combination of gas immersion laser doping (GILD) and laser direct write (LDW) in situ metallization in a commercial SiC wafer. Trimethylaluminum (TMA) and nitrogen are the precursors used to produce p-type and n-type SiC, respectively. Using these techniques, a 150 nm p-type doped junction is fabricated in semiinsulating 6H-SiC and n-doped 4H-SiC wafers. Ohmic contacts are created by laser direct metallization producing carbon rich conductive phases in these doped materials. Alternatively an excimer laser can be used to create silicon rich Schottky contacts. The geometry of the diodes can be vertical or planar to the wafer surface and the laser processes are thought to reduce defect densities in the irradiated areas. These laser-processed diodes are intended for use in high temperature, high voltage and high frequency switching and sensing applications.

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Hydrogel for in Situ Encapsulation of Multiple Black Lipid Membranes

Biophysical Journal ◽

10.1016/j.bpj.2009.12.3292 ◽

2010 ◽

Vol 98 (3) ◽

pp. 604a ◽

Cited By ~ 1

Author(s):

Sania N. Ibragimova ◽

Karin B. Stibius ◽

Piotr P. Szewczykowski ◽

Mark Perry ◽

Henrik Bohr ◽

...

Keyword(s):

Lipid Membranes ◽

Black Lipid Membranes

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Building with ions: towards direct write of platinum nanostructures using in situ liquid cell helium ion microscopy

Nanoscale ◽

10.1039/c7nr04417h ◽

2017 ◽

Vol 9 (35) ◽

pp. 12949-12956 ◽

Cited By ~ 7

Author(s):

Anton V. Ievlev ◽

Jacek Jakowski ◽

Matthew J. Burch ◽

Vighter Iberi ◽

Holland Hysmith ◽

...

Keyword(s):

Ion Beam ◽

Direct Write ◽

High Chemical ◽

Liquid Precursor ◽

Helium Ion ◽

Liquid Cell ◽

Chemical Purity ◽

Ion Microscopy

Direct write with liquid precursor using an helium ion beam, allows fabrication of nanostructures with sub-15 nm resolution and high chemical purity.

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In situ manufacture of magnetic tunnel junctions by a direct-write process

Applied Physics Letters ◽

10.1063/1.4880728 ◽

2014 ◽

Vol 104 (22) ◽

pp. 222401 ◽

Cited By ~ 4

Author(s):

Barry N. Costanzi ◽

Anastasia V. Riazanova ◽

E. Dan Dahlberg ◽

Lyubov M. Belova

Keyword(s):

Tunnel Junctions ◽

Magnetic Tunnel Junctions ◽

Direct Write

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Laser Direct-Write Of Alkaline Microbatteries

MRS Proceedings ◽

10.1557/proc-758-ll3.8 ◽

2002 ◽

Vol 758 ◽

Author(s):

Craig B. Arnold ◽

Alberto Piqué

Keyword(s):

Laser Wavelength ◽

Open Circuit ◽

Constant Current ◽

Direct Write ◽

Ambient Conditions ◽

Forward Transfer ◽

Alkaline Cell ◽

Processing Material ◽

Laser Direct Write

ABSTRACTWe are developing a laser engineering approach to fabricate and optimize various types of alkaline microbatteries. Microbattery cells are produced using a laser forward transfer process that is compatible with the materials required to make the anode, cathode, separator and current collectors. The use of an ultraviolet transfer laser (wavelength = 355 nm, 30 ns FWHM) enables other operations such as surface processing, trimming and micromachining of the transferred materials and substrate and is performed in situ. Such multi-capability for adding, removing and processing material is unique to this direct-write technique and provides the ability to laser pattern complicated structures needed for fabricating complete microbattery assemblies. In this paper, we demonstrate the production of planar zinc-silver oxide alkaline cell by laser direct-write under ambient conditions. The microbattery cells exhibit 1.5–1.6 V open circuit potentials, as expected for the battery chemistry and show flat discharge behavior under constant current loads.

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