scholarly journals A Novel Toolkit for Characterizing the Mechanical and Electrical Properties of Engineered Neural Tissues

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 51 ◽  
Author(s):  
Meghan Robinson ◽  
Karolina Valente ◽  
Stephanie Willerth
Keyword(s):  
Elastic Modulus ◽  
Electrical Properties ◽  
Elastic Moduli ◽  
Direct Method ◽  
Hydrogel Scaffolds ◽  
Force Microscopy ◽  
Mechanical And Electrical Properties ◽  
Atomic Force ◽  
Neural Tissues ◽  
Electrical Signaling

We have designed and validated a set of robust and non-toxic protocols for directly evaluating the properties of engineered neural tissue. These protocols characterize the mechanical properties of engineered neural tissues and measure their electrophysical activity. The protocols obtain elastic moduli of very soft fibrin hydrogel scaffolds and voltage readings from motor neuron cultures. Neurons require soft substrates to differentiate and mature, however measuring the elastic moduli of soft substrates remains difficult to accurately measure using standard protocols such as atomic force microscopy or shear rheology. Here we validate a direct method for acquiring elastic modulus of fibrin using a modified Hertz model for thin films. In this method, spherical indenters are positioned on top of the fibrin samples, generating an indentation depth that is then correlated with elastic modulus. Neurons function by transmitting electrical signals to one another and being able to assess the development of electrical signaling serves is an important verification step when engineering neural tissues. We then validated a protocol wherein the electrical activity of motor neural cultures is measured directly by a voltage sensitive dye and a microplate reader without causing damage to the cells. These protocols provide a non-destructive method for characterizing the mechanical and electrical properties of living spinal cord tissues using novel biosensing methods.

scholarly journals Mechanical and electrical properties of CdTe tetrapods studied by atomic force microscopy

2007 ◽  
Vol 127 (18) ◽  
pp. 184704 ◽  
Author(s):  
Liang Fang ◽  
Jeong Young Park ◽  
Yi Cui ◽  
Paul Alivisatos ◽  
Joshua Shcrier ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Electrical Properties ◽  
Force Microscopy ◽  
Mechanical And Electrical Properties ◽  
Atomic Force

scholarly journals A Universal Model for the Log-Normal Distribution of Elasticity in Polymeric Gels and Its Relevance to Mechanical Signature of Biological Tissues

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Arnaud Millet
Keyword(s):  
Elastic Modulus ◽  
Normal Distribution ◽  
Biological Tissues ◽  
Force Microscopy ◽  
Polymeric Gels ◽  
Atomic Force ◽  
Clear Explanation ◽  
Log Normal ◽  
Log Normal Distribution

The mechanosensitivity of cells has recently been identified as a process that could greatly influence a cell’s fate. To understand the interaction between cells and their surrounding extracellular matrix, the characterization of the mechanical properties of natural polymeric gels is needed. Atomic force microscopy (AFM) is one of the leading tools used to characterize mechanically biological tissues. It appears that the elasticity (elastic modulus) values obtained by AFM presents a log-normal distribution. Despite its ubiquity, the log-normal distribution concerning the elastic modulus of biological tissues does not have a clear explanation. In this paper, we propose a physical mechanism based on the weak universality of critical exponents in the percolation process leading to gelation. Following this, we discuss the relevance of this model for mechanical signatures of biological tissues.

Characterization of Gelatin Composite with Low Content Hydroxyapatite and the Influence on Mesenchymal Stem Cell Culture

2016 ◽  
Vol 675-676 ◽  
pp. 473-476 ◽  
Author(s):  
Junjira Tanum ◽  
Suruk Udomsom ◽  
Wassanai Wattanutchariya ◽  
Pat Sooksaen ◽  
Fahsai Kantawong
Keyword(s):  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Human Mscs ◽  
Natural Bone Mineral ◽  
Hydrogel Scaffolds ◽  
Force Microscopy ◽  
Adhesion Ability ◽  
Atomic Force ◽  
Nanocrystalline Hydroxyapatite ◽  
Composition And Structure

In tussue engineering, hydrogel-based scaffold is one of the most common method for bone tissue engineering. Gelatin is a common material for scaffold, whereas hydroxyapatite (HA) has a similar composition and structure to natural bone mineral. HA can also increase cell adhesion ability of the scaffold. This research focuses on the fabrication of hydrogel scaffolds using gelatin composite with nanocrystalline hydroxyapatite (nHA). Then the mechanical and physical caharacteristics of the scaffold is investigetad. Low contents nHA is introduced into gelatin in order to modulate mesenchymal stem cell (MSC) behavior. There are three types of scaffolds which contain various HA content. The gelatin is crosslinked with glutaraldehyde before freeze-drying. The Young’s modulus of the surface is investigated using Atomic force microscopy (AFM). The pore size is investigated using scanning electron microscope (SEM). Human MSCs are culture on the scaffold for 3 weeks. The result shows the sucesse in cell cultivation. However, the human MSCs cultured on the fabricated hydrogels do not show any lineage-specific differentiation.

Preparation and Research on the Lateral Elastic Modulus of the MnO2 Nanowires

2013 ◽  
Vol 662 ◽  
pp. 84-87
Author(s):  
Yong Jiang ◽  
Jian Cheng Deng ◽  
Yan Huai Ding ◽  
Jiu Ren Yin ◽  
Ping Zhang
Keyword(s):  
Elastic Modulus ◽  
Crystal Form ◽  
Bending Test ◽  
X Ray Diffraction ◽  
Nanowire Diameter ◽  
X Ray ◽  
Three Point Bending ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mno2 Nanowires

MnO2 nanowires with large aspect ratio were successfully synthesized via a hydrothermal method. In this method, Mn(NO3)2 was as a source of manganese and NH4NO3 as an oxidant. The structure and morphology of the MnO2 nanowires were characterized by X ray diffraction (XRD) and scanning electron microscope (SEM). Their lateral elastic modulus was characterized via a nanoscale three-point bending test by atomic force microscopy (AFM) equipped with picoforce. The results indicate that the crystal form of MnO2 was β-MnO2. The elastic modulus of the nanowires decreased with the increase in nanowire diameter. This elastic modulus was in the range of 33.36-77.84GPa as the diameter ranged from 240 to 185nm.

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