scholarly journals Clearing and Labeling Techniques for Large-Scale Biological Tissues

2016 ◽  
Vol 39 (6) ◽  
pp. 439-446 ◽  
Author(s):  
Jinyoung Seo ◽  
Minjin Choe ◽  
Sung-Yon Kim
Keyword(s):  
Large Scale ◽  
Biological Tissues

scholarly journals Small-scale demixing in confluent biological tissues

Soft Matter ◽  
2020 ◽  
Vol 16 (13) ◽  
pp. 3325-3337 ◽  
Author(s):  
Preeti Sahu ◽  
Daniel M. Sussman ◽  
Matthias Rübsam ◽  
Aaron F. Mertz ◽  
Valerie Horsley ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Cell Shape ◽  
Large Scale ◽  
Biological Tissues ◽  
Small Scale

While interfacial tension in confluent cellular mixtures leads to large-scale demixing, cell shape disparity leads to robust small-scale demixing that is observed in experiments and can be explained via neighbor exchange barriers at an interface.

scholarly journals Highly Infectious Prions Generated by a Single Round of Microplate-Based Protein Misfolding Cyclic Amplification

mBio ◽  
2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohammed Moudjou ◽  
Pierre Sibille ◽  
Guillaume Fichet ◽  
Fabienne Reine ◽  
Jérôme Chapuis ◽  
...  
Keyword(s):  
High Throughput ◽  
Protein Misfolding ◽  
Large Scale ◽  
Biological Tissues ◽  
Protein Misfolding Cyclic Amplification ◽  
Bodily Fluids ◽  
Sensitive Tool ◽  
Jakob Disease ◽  
Laboratory Bioassays

ABSTRACTMeasurements of the presence of prions in biological tissues or fluids rely more and more on cell-free assays. Although protein misfolding cyclic amplification (PMCA) has emerged as a valuable, sensitive tool, it is currently hampered by its lack of robustness and rapidity for high-throughput purposes. Here, we made a number of improvements making it possible to amplify the maximum levels of scrapie prions in a single 48-h round and in a microplate format. The amplification rates and the infectious titer of the PMCA-formed prions appeared similar to those derived from thein vivolaboratory bioassays. This enhanced technique also amplified efficiently prions from different species, including those responsible for human variant Creutzfeldt-Jakob disease. This new format should help in developing ultrasensitive, high-throughput prion assays for cognitive, diagnostic, and therapeutic applications.IMPORTANCEThe method developed here allows large-scale, fast, and reliable cell-free amplification of subinfectious levels of prions from different species. The sensitivity and rapidity achieved approach or equal those of other recently developed prion-seeded conversion assays. Our simplified assay may be amenable to high-throughput, automated purposes and serve in a complementary manner with other recently developed assays for urgently needed antemortem diagnostic tests, by using bodily fluids containing small amounts of prion infectivity. Such a combination of assays is of paramount importance to reduce the transfusion risk in the human population and to identify asymptomatic carriers of variant Creutzfeldt-Jakob disease.

scholarly journals Mesoscale substrate curvature overrules nanoscale contact guidance to direct bone marrow stromal cell migration

2018 ◽  
Vol 15 (145) ◽  
pp. 20180162 ◽  
Author(s):  
Maike Werner ◽  
Nicholas A. Kurniawan ◽  
Gabriela Korus ◽  
Carlijn V. C. Bouten ◽  
Ansgar Petersen
Keyword(s):  
Bone Marrow ◽  
Cellular Response ◽  
Large Scale ◽  
Biological Tissues ◽  
Collagen Fibrils ◽  
Contact Guidance ◽  
Cylinder Axis ◽  
Cylinder Diameter ◽  
Substrate Curvature ◽  
And Migration

The intrinsic architecture of biological tissues and of implanted biomaterials provides cells with large-scale geometrical cues. To understand how cells are able to sense and respond to complex structural environments, a deeper insight into the cellular response to multi-scale and conflicting geometrical cues is needed. In this study, we subjected human bone marrow stromal cells (hBMSCs) to mesoscale cylindrical surfaces (diameter 250–5000 µm) and nanoscale collagen fibrils (diameter 100–200 nm) that were aligned perpendicular to the cylinder axis. On flat surfaces and at low substrate curvatures (cylinder diameter d > 1000 µm), cell alignment and migration were governed by the nanoscale collagen fibrils, consistent with the contact guidance effect. With increasing surface curvature (decreasing cylinder diameter, d < 1000 µm), cells increasingly aligned and migrated along the cylinder axis, i.e. the direction of zero curvature. An increase in phosphorylated myosin light chain levels was observed with increasing substrate curvature, suggesting a link between substrate-induced cell bending and the F-actin–myosin machinery. Taken together, this work demonstrates that geometrical cues of up to 10× cell size can play a dominant role in directing hBMSC alignment and migration and that the effect of nanoscale contact guidance can even be overruled by mesoscale curvature guidance.

scholarly journals Cellular maps of gastrointestinal organs: getting the most from tissue clearing

2020 ◽  
Vol 319 (1) ◽  
pp. G1-G10
Author(s):  
Cambrian Y. Liu ◽  
D. Brent Polk
Keyword(s):  
Large Scale ◽  
Alimentary Tract ◽  
Three Dimensional ◽  
Short Review ◽  
Biological Tissues ◽  
Tissue Clearing ◽  
Relative Paucity ◽  
Whole Mount ◽  
Chemical Concepts ◽  
The Impact

The development of modern methods to induce optical transparency (“clearing”) in biological tissues has enabled the three-dimensional (3D) reconstruction of intact organs at cellular resolution. New capabilities in visualization of rare cellular events, long-range interactions, and irregular structures will facilitate novel studies in the alimentary tract and gastrointestinal systems. The tubular geometry of the alimentary tract facilitates large-scale cellular reconstruction of cleared tissue without specialized microscopy setups. However, with the rapid pace of development of clearing agents and current relative paucity of research groups in the gastrointestinal field using these techniques, it can be daunting to incorporate tissue clearing into experimental workflows. Here, we give some advice and describe our own experience bringing tissue clearing and whole mount reconstruction into our laboratory’s investigations. We present a brief overview of the chemical concepts that underpin tissue clearing, what sorts of questions whole mount imaging can answer, how to choose a clearing agent, an example of how to clear and image alimentary tissue, and what to do after obtaining the image. This short review will encourage other gastrointestinal researchers to consider how utilizing tissue clearing and creating 3D “maps” of tissue might deepen the impact of their studies.

scholarly journals A minimal-length approach unifies rigidity in underconstrained materials

2019 ◽  
Vol 116 (14) ◽  
pp. 6560-6568 ◽  
Author(s):  
Matthias Merkel ◽  
Karsten Baumgarten ◽  
Brian P. Tighe ◽  
M. Lisa Manning
Keyword(s):  
Shear Modulus ◽  
Material Properties ◽  
First Principles ◽  
Large Scale ◽  
Biological Tissues ◽  
Minimal Length ◽  
Imaging Data ◽  
Poynting Effect ◽  
2D And 3D ◽  
Local Geometric Structure

We present an approach to understand geometric-incompatibility–induced rigidity in underconstrained materials, including subisostatic 2D spring networks and 2D and 3D vertex models for dense biological tissues. We show that in all these models a geometric criterion, represented by a minimal lengthℓ¯min, determines the onset of prestresses and rigidity. This allows us to predict not only the correct scalings for the elastic material properties, but also the precise magnitudes for bulk modulus and shear modulus discontinuities at the rigidity transition as well as the magnitude of the Poynting effect. We also predict from first principles that the ratio of the excess shear modulus to the shear stress should be inversely proportional to the critical strain with a prefactor of 3. We propose that this factor of 3 is a general hallmark of geometrically induced rigidity in underconstrained materials and could be used to distinguish this effect from nonlinear mechanics of single components in experiments. Finally, our results may lay important foundations for ways to estimateℓ¯minfrom measurements of local geometric structure and thus help develop methods to characterize large-scale mechanical properties from imaging data.

scholarly journals CMU Array: A 3D Nano-Printed, Customizable Ultra-High-Density Microelectrode Array Platform

2019 ◽  
Author(s):  
Mohammad Sadeq Saleh ◽  
Sandra M. Ritchie ◽  
Mark A. Nicholas ◽  
Rriddhiman Bezbaruah ◽  
Jay W. Reddy ◽  
...  
Keyword(s):  
Large Scale ◽  
Microelectrode Array ◽  
Printed Circuit Boards ◽  
Biological Tissues ◽  
Circuit Boards ◽  
Clinical Neuroscience ◽  
Printed Circuit ◽  
Computer Interfaces ◽  
3D Printed ◽  
Technological Limitations

AbstractMicroelectrode arrays (MEAs) provide the means to record electrophysiological activity fundamental to both basic and clinical neuroscience (e.g. brain-computer interfaces). Despite recent advances, current MEAs have significant limitations – including low recording density, fragility, expense, and the inability to optimize the probe to individualized study or patient needs. Here we address the technological limitations through the utilization of the newest developments in 3D nanoparticle printing.1 Our ‘CMU Arrays’ possess previously impossible electrode densities (> 6000 channels/cm2) with tip diameters as small as 10 μm. Most importantly, the probes are entirely customizable owing to the adaptive manufacturing process. Any combination of individual shank lengths, impedances, and layouts are possible. This is achieved in part via our new multi-layer, multi material, custom 3D-printed circuit boards, a fabrication advancement in itself. This device design enables new experimental avenues of targeted, large-scale recording of electrical signals from a variety of biological tissues.

scholarly journals Opto-E-Dura: a Soft, Stretchable ECoG Array for Multimodal, Multi-scale Neuroscience

2020 ◽  
Author(s):  
Aline F. Renz ◽  
Jihyun Lee ◽  
Klas Tybrandt ◽  
Maciej Brzezinski ◽  
Dayra A. Lorenzo ◽  
...  
Keyword(s):  
Brain Function ◽  
Large Scale ◽  
Spatial Scales ◽  
Biological Tissues ◽  
Great Promise ◽  
Wide Field ◽  
Electrode Arrays ◽  
Spatial And Temporal Scales ◽  
Multi Scale ◽  
The Brain

AbstractSoft, stretchable materials hold great promise for the fabrication of biomedical devices due to their capacity to integrate gracefully with and conform to biological tissues. Conformal devices are of particular interest in the development of brain interfaces where rigid structures can lead to tissue damage and loss of signal quality over the lifetime of the implant. Interfaces to study brain function and dysfunction increasingly require multimodal access in order to facilitate measurement of diverse physiological signals that span the disparate temporal and spatial scales of brain dynamics. Here we present the Opto-e-Dura, a soft, stretchable, 16-channel electrocorticography array that is optically transparent. We demonstrate its compatibility with diverse optical and electrical readouts enabling multimodal studies that bridge spatial and temporal scales. The device is chronically stable for weeks, compatible with wide-field and 2-photon calcium imaging and permits the repeated insertion of penetrating multi-electrode arrays. As the variety of sensors and effectors realizable on soft, stretchable substrates expands, similar devices that provide large-scale, multimodal access to the brain will continue to improve fundamental understanding of brain function.

scholarly journals Microfluidic device integrating a network of hyper-elastic valves for automated glucose stimulation and insulin secretion collection from a single pancreatic islet

2021 ◽  
Author(s):  
Clement Quintard ◽  
Emily Tubbs ◽  
Jean-Luc Achard ◽  
Fabrice Navarro ◽  
Xavier Gidrol ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Pancreatic Islet ◽  
Large Scale ◽  
Biological Tissues ◽  
Microfluidic Platforms ◽  
User Friendliness ◽  
Glucose Stimulation ◽  
Automated Control ◽  
Microphysiological Systems ◽  
Hyper Elastic

Advances in microphysiological systems have prompted the need for robust and reliable cell culture devices. While microfluidic technology has made significant progress, devices often lack user-friendliness and are not designed to be industrialized on a large scale. Pancreatic islets are often being studied using microfluidic platforms in which the monitoring of fluxes is generally very limited, especially because the integration of valves to direct the flow is difficult to achieve. Considering these constraints, we present a thermoplastic manufactured microfluidic chip with an automated control of fluxes for the stimulation and secretion collection of pancreatic islet. The islet was directed toward precise locations through passive hydrodynamic trapping and both dynamic glucose stimulation and insulin harvesting were done automatically via a network of large deformation valves, directing the reagents and the pancreatic islet toward different pathways. This device we developed enables monitoring of insulin secretion from a single islet and can be adapted for the study of a wide variety of biological tissues and secretomes.

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