scholarly journals Molecular motor-driven filament transport across three-dimensional, polymeric micro-junctions

2021 ◽  
Author(s):  
Cordula Reuther ◽  
Sönke Steenhusen ◽  
Christoph Meinecke ◽  
pradheebha surendiran ◽  
Aseem Salhotra ◽  
...  
Keyword(s):  
Molecular Motors ◽  
Molecular Motor ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Transport Systems ◽  
Focal Volume ◽  
Lab On Chip ◽  
Glass Substrates ◽  
Organic Hybrid ◽  
On Chip

Abstract Molecular motor-driven filament systems have been extensively explored for biomedical and nanotechnological applications such as lab-on-chip molecular detection or network-based biocomputation. In these applications, filament transport conventionally occurs in two dimensions (2D), often guided along open, topographically and/or chemically structured channels which are coated by molecular motors. However, at crossing points of different channels the filament direction is less well determined and, though crucial to many applications, reliable guiding across the junction can often not be guaranteed. We here present a three-dimensional (3D) approach that eliminates the possibility for filaments to take wrong turns at junctions by spatially separating the channels crossing each other. Specifically, 3D junctions with tunnels and overpasses were manufactured on glass substrates by two-photon polymerization, a 3D fabrication technology where a tightly focused, femtosecond-pulsed laser is scanned in a layer-to-layer fashion across a photo-polymerizable inorganic-organic hybrid polymer (ORMOCER®) with µm resolution. Solidification of the polymer was confined to the focal volume, enabling the manufacturing of arbitrary 3D microstructures according to CAD data. Successful realization of the 3D junction design was verified by optical and electron microscopy. Most importantly, we demonstrated the reliable transport of filaments, namely microtubules propelled by kinesin-1 motors, across these 3D junctions without junction errors. Our results open up new possibilities for 3D functional elements in biomolecular transport systems, in particular their implementation in biocomputational networks.

A Dynamic Escape Problem of Molecular Motors

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Dean Culver ◽  
Bryan Glaz ◽  
Samuel Stanton
Keyword(s):  
Molecular Motors ◽  
Binding Sites ◽  
Molecular Motor ◽  
Myosin Ii ◽  
Three Dimensional ◽  
Production Capacity ◽  
Force Production ◽  
Actin Binding ◽  
Three Dimensional Model ◽  
Thermal Agitation

Abstract Animal skeletal muscle exhibits very interesting behavior at near-stall forces (when the muscle is loaded so strongly that it can barely contract). Near this physical limit, the myosin II proteins may be unable to reach advantageous actin binding sites through simple attractive forces. It has been shown that the advantageous utilization of thermal agitation is a likely source for an increased force-production capacity and reach in myosin-V (a processing motor protein), and here we explore the dynamics of a molecular motor without hand-over-hand motion including Brownian motion to show how local elastic energy well boundaries may be overcome. We revisit a spatially two-dimensional mechanical model to illustrate how thermal agitation can be harvested for useful mechanical work in molecular machinery inspired by this biomechanical phenomenon without rate functions or empirically inspired spatial potential functions. Additionally, the model accommodates variable lattice spacing, and it paves the way for a full three-dimensional model of cross-bridge interactions where myosin II may be azimuthally misaligned with actin binding sites. With potential energy sources based entirely on realizable components, this model lends itself to the design of artificial, molecular-scale motors.

Fabrication of three-dimensional microstructures based on singled-layered SU-8 for lab-on-chip applications

2006 ◽  
Vol 127 (2) ◽  
pp. 228-234 ◽  
Author(s):  
Hui Yu ◽  
Oluwaseyi Balogun ◽  
Biao Li ◽  
T.W. Murray ◽  
Xin Zhang
Keyword(s):  
Three Dimensional ◽  
Lab On Chip ◽  
On Chip

Three-dimensional integrated circuits for lab-on-chip dielectrophoresis of nanometer scale particles

2007 ◽  
Author(s):  
Samuel J. Dickerson ◽  
Arnaldo J. Noyola ◽  
Steven P. Levitan ◽  
Donald M. Chiarulli
Keyword(s):  
Integrated Circuits ◽  
Three Dimensional ◽  
Nanometer Scale ◽  
Lab On Chip ◽  
On Chip

scholarly journals Fabrication of Three-Dimensional Microvalves of Internal Nested Structures Inside Fused Silica

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 43
Author(s):  
Chao Shan ◽  
Qing Yang ◽  
Hao Bian ◽  
Xun Hou ◽  
Feng Chen
Keyword(s):  
Three Dimensional ◽  
Fused Silica ◽  
Wet Etching ◽  
Hard Material ◽  
The Novel ◽  
Lab On Chip ◽  
Step Process ◽  
Spherical Structure ◽  
Nested Structures ◽  
On Chip

Nested structures inside the hard material play a pivotal role in the microfluidics systems, such as the microvalve and the micropump. In this article, we demonstrate a novel and facile method of fabricating nested structures inside the fused silica with a two-step process femtosecond laser wet etching (FLWE) process. Inside fused silica, a spherical structure was made with a diameter of nearly 80 µm in a square chamber. In addition, we designed a simple microvalve with this sphere controlling the current’s flow. The novel microvalve structure can be easily integrated into the functional microfluidics systems and will be widely applied in the Lab-on-chip (LOC) system.

Three-dimensional microfluidic structure embedded in photostructurable glass by femtosecond laser for lab-on-chip applications

2004 ◽  
Vol 79 (4-6) ◽  
pp. 815-817 ◽  
Author(s):  
K. Sugioka ◽  
M. Masuda ◽  
T. Hongo ◽  
Y. Cheng ◽  
K. Shihoyama ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Three Dimensional ◽  
Lab On Chip ◽  
On Chip ◽  
Photostructurable Glass ◽  
Microfluidic Structure

Three-Dimensional Microfluidic Focusing With Surface Charge Patterning

2005 ◽  
Author(s):  
Jeffrey T. Coleman ◽  
David Sinton
Keyword(s):  
Surface Charge ◽  
Three Dimensional ◽  
Memory Storage ◽  
Surface Patch ◽  
Hydrodynamic Focusing ◽  
Cross Sectional ◽  
Lab On Chip ◽  
Surface Patches ◽  
Sectional Surface ◽  
On Chip

Electrokinetically-driven flow circulations resulting from heterogeneous surface patches have previously been employed to improve mixing in microchannels. Here, numerical simulations demonstrate local in-channel hydrodynamic focusing through the use of strategically-patterned surface charge. Presented first is the case of a single straight channel with an axially-localized cross-sectional surface patch (ring). The surface patch exhibits a zeta potential equal in magnitude to the native microchannel surface but opposite in sign. The unsteady species transport in the presence of the electrokinetically-induced circulations is modelled, and a mean residence time is quantified. In general, residence times indicate the potential application of these circulations to microfluidic-based memory storage. Next, an improved focusing process for pinched-injection is demonstrated that exploits non-uniform surface patches. Lastly, surface patches are applied to enhance stream focusing in the microfluidic cross geometry. It is demonstrated that with this technique three-dimensional hydrodynamic focusing can be achieved in a single planar microfluidic structure. In one case, the microfluidic fluid stream was constrained to the centre of the channel and focused to 12% of its original cross-sectional area. Extensions of this work are discussed, as are the microfabrication and surface modification processes required for lab-on-chip implementation of these numerically simulated processes.

Analysis and Simulation of a Micro Hydrocyclone Device for Particle Liquid Separation

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
P. Bagdi ◽  
P. Bhardwaj ◽  
A. K. Sen
Keyword(s):  
Stokes Equations ◽  
Separation Efficiency ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Group Model ◽  
Operational Parameters ◽  
Lab On Chip ◽  
Dimensional Group ◽  
Simulation Results ◽  
On Chip

This paper presents a three-dimensional simulation of a micro hydrocyclone for the separation of micron sized particles from liquid in a particulated sample. A theoretical analysis is performed to demonstrate the working principle of the micro hydrocyclone and develop design models. The geometry of the proposed device is designed based on the Bradley model, since it offers a lower cut-size, thus making it suitable for microfluidics applications. The operational parameters of the hydrocyclone are derived from a dimensional group model. The particle separation process inside the micro hydrocyclone is simulated by solving fluid flows using Navier-Stokes equations and particle dynamics using the Lagrangian approach in a Eulerean fluid. First, the numerical model is validated by comparing the simulation results with the experimental results for a macroscale hydrocyclone reported in the literature. Then, the micro hydrocyclone is simulated and the simulation results are presented and discussed in the context of the functioning of the micro hydrocyclone. Finally, the effects of inlet velocity, vortex finder diameter, particle size, and density on the separation efficiency are investigated. The proposed device can be easily integrated with micro-environments; thus, is suitable for lab-on-chip and microsystems development.

scholarly journals Innovative 3D Microfluidic Tools for On-Chip Fluids and Particles Manipulation: From Design to Experimental Validation

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 104
Author(s):  
Sofia Zoupanou ◽  
Maria Serena Chiriacò ◽  
Iolena Tarantini ◽  
Francesco Ferrara
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Liquid Composition ◽  
Fluorescent Nanoparticles ◽  
Lab On Chip ◽  
Essential Components ◽  
3D Architecture ◽  
Low Efficiency ◽  
On Chip ◽  
Good Transparency

Micromixers are essential components in lab-on-a-chip devices, of which the low efficiency can limit many bio-application studies. Effective mixing with automation capabilities is still a crucial requirement. In this paper, we present a method to fabricate a three-dimensional (3D) poly(methyl methacrylate) (PMMA) fluidic mixer by combining computer-aided design (CAD), micromilling technology, and experimental application via manipulating fluids and nanoparticles. The entire platform consists of three microfabricated layers with a bottom reservoir-shaped microchannel, a central serpentine channel, and a through-hole for interconnection and an upper layer containing inlets and outlet. The sealing process of the three layers and the high-precision and customizable methods used for fabrication ensure the realization of the monolithic 3D architecture. This provides buried running channels able to perform passive chaotic mixing and dilution functions, thanks to a portion of the pathway in common between the reservoir and serpentine layers. The possibility to plug-and-play micropumping systems allows us to easily demonstrate the feasibility and working features of our device for tracking the mixing and dilution performances of the micromixer by using colored fluids and fluorescent nanoparticles as the proof of concept. Exploiting the good transparency of the PMMA, spatial liquid composition and better control over reaction variables are possible, and the real-time monitoring of experiments under a fluorescence microscope is also allowed. The tools shown in this paper are easily integrable in more complex lab-on-chip platforms.

scholarly journals Processivity of molecular motors under vectorial loads

2020 ◽  
Author(s):  
Hamid Khataee ◽  
Zoltan Neufeld ◽  
Mohammed Mahamdeh
Keyword(s):  
Molecular Motors ◽  
Molecular Motor ◽  
Average Distance ◽  
Three Dimensional ◽  
Transition Rates ◽  
Spatial Organisation ◽  
Load Dependence ◽  
Detachment Rate ◽  
Kinetic Transition ◽  
Load Angle

AbstractMolecular motors are cellular machines that drive the spatial organisation of the cells by transporting cargoes along intracellular filaments. Although the mechanical properties of single molecular motors are relatively well characterised, it remains elusive how the three-dimensional geometry of a load imposed on a motor affects its processivity, i.e., the average distance that a motor moves per interaction with a filament. Here, we theoretically explore this question for a single kinesin molecular motor by analysing the load-dependence of the stepping and detachment processes. We find that the processivity of kinesin increases with lowering the load angle between kinesin and microtubule filament, due to the deceleration of the detachment rate. When the load angle is large, the processivity is predicted to enhance with accelerating the stepping rate, through an optimal distribution of the load over the kinetic transition rates underlying a mechanical step of the motor. These results provide new insights into understanding of the design of potential synthetic biomolecular machines that can travel long distances with high velocities.

Laser Scanning Confocal Microscopy and Three-Dimesnsional Reconstruction of the Mitotic Spindles of Unequally Dividing Embryonic Cells

1990 ◽  
Vol 48 (3) ◽  
pp. 166-167
Author(s):  
J. Holy ◽  
G. Schatten
Keyword(s):  
Confocal Microscopy ◽  
Mitotic Spindle ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Two Dimensions ◽  
Embryonic Cells ◽  
Mitotic Spindles ◽  
Cleavage Division ◽  
Scanning Confocal Microscopy

One of the classic limitations of light microscopy has been the fact that three dimensional biological events could only be visualized in two dimensions. Recently, this shortcoming has been overcome by combining the technologies of laser scanning confocal microscopy (LSCM) and computer processing of microscopical data by volume rendering methods. We have employed these techniques to examine morphogenetic events characterizing early development of sea urchin embryos. Specifically, the fourth cleavage division was examined because it is at this point that the first morphological signs of cell differentiation appear, manifested in the production of macromeres and micromeres by unequally dividing vegetal blastomeres.The mitotic spindle within vegetal blastomeres undergoing unequal cleavage are highly polarized and develop specialized, flattened asters toward the micromere pole. In order to reconstruct the three-dimensional features of these spindles, both isolated spindles and intact, extracted embryos were fluorescently labeled with antibodies directed against either centrosomes or tubulin.

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