Microfluidic Emulsion Generation and Trapping Enabling Droplet-Interfaced Bilayer Lipid Membrane Arrays

2009 ◽  
Author(s):  
C. Shao ◽  
D. L. DeVoe
Keyword(s):  
Lipid Bilayers ◽  
Single Molecule ◽  
Protein Interactions ◽  
Lipid Membranes ◽  
High Throughput Screening ◽  
Lipid Membrane ◽  
Bilayer Lipid Membrane ◽  
Single Molecule Level ◽  
Bilayer Lipid ◽  
Ion Translocation

Freestanding bilayer lipid membranes provide an exceptional platform for measurements of lipid/protein interactions and ion translocation events at the single molecule level. For drug screening applications, large arrays of individual bilayer supports are required. However, an effective method for generating, stabilizing, and monitoring arrays of lipid bilayers remains elusive. Here we investigate a novel approach towards the facile generation of bilayer arrays for high throughput screening. The approach takes advantage of fundamental microfluidic capabilities by combining an emulsion generator with droplet-interfaced membrane formation, allowing for fully-automated production of membrane arrays whose density is, in principle, unlimited.

Self-Healing Bilayer Lipid Membranes Formed Over Synthetic Substrates

2008 ◽  
Author(s):  
M. Austin Creasy ◽  
Donald J. Leo
Keyword(s):  
Self Assembly ◽  
Lipid Membranes ◽  
Lipid Membrane ◽  
Bilayer Lipid Membrane ◽  
Unique Property ◽  
Bilayer Lipid Membranes ◽  
Self Healing ◽  
Electrical Field ◽  
Bilayer Lipid ◽  
Recent Experimental Study

Biological systems demonstrate autonomous healing of damage and are an inspiration for developing self-healing materials. Our recent experimental study has demonstrated that a bilayer lipid membrane (BLM), also called a black lipid membrane, has the ability to self-heal after mechanical failure. These molecules have a unique property that they spontaneously self assembly into organized structures in an aqueous medium. The BLM forms an impervious barrier to ions and fluid between two volumes and strength of the barrier is dependent on the pressure and electrical field applied to the membrane. A BLM formed over an aperture on a silicon substrate is shown to self-heal for 5 pressurization failure cycles.

Single molecule measurements within individual membrane-bound ion channels using a polymer-based bilayer lipid membrane chip

Lab on a Chip ◽  
2008 ◽  
Vol 8 (4) ◽  
pp. 602 ◽  
Author(s):  
Louis P. Hromada ◽  
Brian J. Nablo ◽  
John J. Kasianowicz ◽  
Michael A. Gaitan ◽  
Don L. DeVoe
Keyword(s):  
Ion Channels ◽  
Single Molecule ◽  
Lipid Membrane ◽  
Bilayer Lipid Membrane ◽  
Bilayer Lipid ◽  
Membrane Bound

scholarly journals The amphoteric cartilage surface tested in the pH Range from 2.0 to 9.0

2022 ◽  
Vol 3 (1) ◽  
pp. 01-04
Author(s):  
Zenon Pawlak ◽  
Michal Sojka
Keyword(s):  
Friction Coefficient ◽  
Surface Energy ◽  
Lipid Bilayers ◽  
Lipid Membrane ◽  
Bilayer Lipid Membrane ◽  
Bell Curve ◽  
Bilayer Lipid ◽  
Charged Surfaces ◽  
Pin On Disc ◽  
Novel Concept

Background: Phospholipids adsorbed to negatively-charged proteoglycan matrix form phospholipid (membrane), have negatively charged surface (-PO4-) and are hydrophilic. Strong adsorption and strong cohesion are necessary for phospholipids to provide a good lubricant. The surface energy of spherical lipid bilayers have "bell-curve" shaped has amphoteric character and lowest surface energy at a pH 7.4 ± 1 of the natural joint. Objectives: The amphoteric character of the natural surface of the articular cartilage was determined by measuring the surface energy of the model spherical bilayer lipid membrane. It was found that the friction (f) vs. pH 2.0 to 9.0 of the pair (cartilage/cartilage) has the amphoteric character by exposing "bell-curve" shaped with an isoelectric point (IEP). Methods: The friction coefficient (f) was measured with the sliding pin-on-disc tribotester the friction between two surfaces (cartilage/cartilage) pair. The method of interfacial tension measurements of the spherical lipid bilayer model vs the pH over the range 0.2 to 9.0 was used. Results: The dependence of friction coefficient between two cartilage surfaces on the pH over the range 2.0 to 9.0 is demonstrated by a “bell - curve” in Fig. 2(A). The surface energy of a model spherical bilayer lipid membrane vs. the pH has the character of a “bell - curve” with an (IEP) is shown in Fig. 2(B). Conclusion: The amphoteric effect on friction between the bovine cartilage/cartilage contacts has been found to be highly sensitive to the pH of an aqueous solution. In this paper we demonstrate experimentally that the pH sensitivity of cartilage to friction provides a novel concept in joint lubrication on charged surfaces. The change in friction was consistently related to the change of charge density of an amphoteric surface.

scholarly journals De Novo Design of a Nanopore for DNA Detection that Incorporates a β-Hairpin Peptide

2021 ◽  
Author(s):  
Keisuke Shimizu ◽  
Batsaikhan Mijiddorj ◽  
Masataka Usami ◽  
Shuhei Yoshida ◽  
Shiori Akayama ◽  
...  
Keyword(s):  
Single Molecule ◽  
Protein Design ◽  
Lipid Membrane ◽  
De Novo ◽  
Three Dimensional ◽  
Bilayer Lipid Membrane ◽  
De Novo Design ◽  
Dimensional Structure ◽  
Practical Applications ◽  
Single Molecule Level

Abstract The amino acid sequence of a protein encodes information on its three-dimensional structure and specific functionality. De novo protein design has emerged as a method to manipulate the primary structure for the development of artificial proteins and peptides with desired functionality. This paper describes the de novo design of a pore-forming peptide that has a β-hairpin structure and assembles to form a stable nanopore in a bilayer lipid membrane. This large synthetic nanopore is an entirely artificial device with practical applications. This peptide, named SV28, forms nanopore structures ranging from 1.6 to 6.2 nm in diameter assembled from 7 to 18 monomers. The nanopore formed with a diameter of 5 nm is able to detect long double-stranded DNA (dsDNA) with 1 kbp length. Moreover, the larger sized nanopore can discriminate and human telomeric DNA (G-quadruplex, G4). The blocking current signals allowed us to investigate the translocation behavior of dsDNA or G4 structure at the single molecule level. Such de novo design of peptide sequences has the potential to create novel nanopores, which would be applicable in molecular transporter between across lipid membrane.

De Novo Design of a Nanopore for DNA Detection Incorporating a β-hairpin Peptide

2020 ◽  
Author(s):  
Keisuke Shimizu ◽  
Batsaikhan Mijiddorj ◽  
Shuhei Yoshida ◽  
Shiori Akayama ◽  
Yoshio Hamada ◽  
...  
Keyword(s):  
Single Molecule ◽  
Protein Design ◽  
Lipid Membrane ◽  
De Novo ◽  
Three Dimensional ◽  
Bilayer Lipid Membrane ◽  
De Novo Design ◽  
Dimensional Structure ◽  
Practical Applications ◽  
Single Molecule Level

The amino acid sequence of a protein encodes information on its three-dimensional structure and specific functionality. De novo protein design has emerged as a method to manipulate the primary structure for the development of artificial proteins and peptides with desired functionality. This paper describes the de novo design of a pore-forming peptide that has a β-hairpin structure and assembles to form a stable nanopore in a bilayer lipid membrane. This large synthetic nanopore is an entirely artificial device with practical applications. This peptide, named SV28, forms nanopore structures ranging from 1.6 to 6.2 nm in diameter assembled from 7 to 18 monomers. The nanopore formed with a diameter of 5 nm is able to detect long double-stranded DNA (dsDNA) with 1 kbp length, and measurement of current signals allowed us to investigate the translocation behavior of dsDNA at the single molecule level. Such de novo design of peptide sequences has the potential to create assembled structure in lipid membrane such as novel nanopores, which would also be applicable in molecular transporter between inside and outside of lipid membrane.

Failure Characteristics of Bilayer Lipid Membranes (BLMs) Formed over a Single Pore

2007 ◽  
Vol 1061 ◽  
Author(s):  
David Hopkinson ◽  
Donald J. Leo
Keyword(s):  
Lipid Membranes ◽  
Lipid Membrane ◽  
Bilayer Lipid Membrane ◽  
Maximum Pressure ◽  
Pressure Curve ◽  
Failure Characteristics ◽  
Test Fixture ◽  
Failure Pressure ◽  
Bilayer Lipid ◽  
Experimental Pressure

ABSTRACTA new methodology has been developed to measure the maximum pressure that can be withstood by a bilayer lipid membrane (BLM) formed over porous substrates. A custom test fixture was fabricated to pressurize BLMs in very fine increasing increments until they fail. This experiment was performed on 1-Stearoyl-2-Oleoyl-sn-Glycero-3-Phosphatidylocholine (SOPC) BLMs formed over polycarbonate substrates with a single pore ranging from 5 to 20 microns in diameter. Failure pressure was found to be inversely proportional to pore diameter. The same set of experiments was repeated for BLMs that were formed from a mixture of SOPC and 50 mol% cholesterol (CHOL). The presence of cholesterol was found to increase the failure pressure of the BLMs by 56% on average. A model of the characteristic pressure curve from this experiment was developed based on the pressurization and flow of fluid through a porous substrate. The model was found to accurately fit the experimental pressure curves.

scholarly journals De Novo Design of a Nanopore for DNA Detection Incorporating a β-hairpin Peptide

2020 ◽  
Author(s):  
Keisuke Shimizu ◽  
Batsaikhan Mijiddorj ◽  
Shuhei Yoshida ◽  
Shiori Akayama ◽  
Yoshio Hamada ◽  
...  
Keyword(s):  
Single Molecule ◽  
Protein Design ◽  
Lipid Membrane ◽  
De Novo ◽  
Three Dimensional ◽  
Bilayer Lipid Membrane ◽  
De Novo Design ◽  
Dimensional Structure ◽  
Practical Applications ◽  
Single Molecule Level

The amino acid sequence of a protein encodes information on its three-dimensional structure and specific functionality. De novo protein design has emerged as a method to manipulate the primary structure for the development of artificial proteins and peptides with desired functionality. This paper describes the de novo design of a pore-forming peptide that has a β-hairpin structure and assembles to form a stable nanopore in a bilayer lipid membrane. This large synthetic nanopore is an entirely artificial device with practical applications. This peptide, named SV28, forms nanopore structures ranging from 1.6 to 6.2 nm in diameter assembled from 7 to 18 monomers. The nanopore formed with a diameter of 5 nm is able to detect long double-stranded DNA (dsDNA) with 1 kbp length, and measurement of current signals allowed us to investigate the translocation behavior of dsDNA at the single molecule level. Such de novo design of peptide sequences has the potential to create assembled structure in lipid membrane such as novel nanopores, which would also be applicable in molecular transporter between inside and outside of lipid membrane.

De Novo Design of a Nanopore for DNA Detection Incorporating a β-hairpin Peptide

2020 ◽  
Author(s):  
Keisuke Shimizu ◽  
Batsaikhan Mijiddorj ◽  
Shuhei Yoshida ◽  
Shiori Akayama ◽  
Yoshio Hamada ◽  
...  
Keyword(s):  
Single Molecule ◽  
Protein Design ◽  
Lipid Membrane ◽  
De Novo ◽  
Three Dimensional ◽  
Bilayer Lipid Membrane ◽  
De Novo Design ◽  
Dimensional Structure ◽  
Practical Applications ◽  
Single Molecule Level

The amino acid sequence of a protein encodes information on its three-dimensional structure and specific functionality. De novo protein design has emerged as a method to manipulate the primary structure for the development of artificial proteins and peptides with desired functionality. This paper describes the de novo design of a pore-forming peptide that has a β-hairpin structure and assembles to form a stable nanopore in a bilayer lipid membrane. This large synthetic nanopore is an entirely artificial device with practical applications. This peptide, named SV28, forms nanopore structures ranging from 1.6 to 6.2 nm in diameter assembled from 7 to 18 monomers. The nanopore formed with a diameter of 5 nm is able to detect long double-stranded DNA (dsDNA) with 1 kbp length, and measurement of current signals allowed us to investigate the translocation behavior of dsDNA at the single molecule level. Such de novo design of peptide sequences has the potential to create assembled structure in lipid membrane such as novel nanopores, which would also be applicable in molecular transporter between inside and outside of lipid membrane.

Evaluating the Failure Pressure of Bilayer Lipid Membranes by a Controllable Electromagnetic Test Fixture

Aerospace ◽  
2006 ◽  
Author(s):  
David P. Hopkinson ◽  
Raffaella De Vita ◽  
Donald J. Leo
Keyword(s):  
Internal Pressure ◽  
Lipid Membranes ◽  
Fluid Transport ◽  
Lipid Membrane ◽  
Bilayer Lipid Membrane ◽  
Test Fixture ◽  
Failure Pressure ◽  
Bilayer Lipid ◽  
Electromagnetic Test ◽  
Series Of Experiments

The motion of plants is the inspiration for a new biomimetic actuator that uses fluid transport across a bilayer lipid membrane (BLM) to create internal pressure and cause displacement in the actuator. In order for the actuator to be viable the BLM must be able to withstand this internal pressure without failing. In a previous study, BLMs were formed over a porous polycarbonate substrate and a hydrostatic pressure was applied to the BLM and gradually increased until failure. This test was performed over different pore sizes to measure the failure pressure of the BLM as a function of pore radius. To improve this series of experiments, a new test fixture has been developed that will allow for a more precise measurement of the failure pressure as well as an expanded range of failure pressures. It is computer controlled, using an electromagnetic actuator to pressurize the BLMs and a pressure transducer to monitor pressure. The design scheme for this test fixture and some preliminary results will be presented.

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