Development of Hybrid Electromagnetic and Mechanical Stimulation System for Enhancement of Nerve Axonal Extension

2016 ◽  
Author(s):  
Kazuya Matsumoto ◽  
Yusuke Morita ◽  
Eiji Nakamachi
Keyword(s):  
Magnetic Field ◽  
Nerve Cell ◽  
Mechanical Stimulation ◽  
Small Error ◽  
Cyclic Stretch ◽  
Nerve Tissue ◽  
Enhancement Effect ◽  
Axonal Extension ◽  
Stimulation System

Recently, the electromagnetic and mechanical stimulation have been recognized as the effective extracellular environmental factor to enhance the defected peripheral nerve tissue regeneration. We designed and fabricated a bioreactor device, which can load the uniform AC magnetic field (ACMF) and the uniform tensile strain to stimulate PC12 nerve cell. For ACMF stimulation system, we used the pole piece structure to enable the uniform ACMF and in-situ microscopic observation. We confirmed the uniformity of magnetic field in the experiments. Further, the uniform strain in the stretch stimulation device was confirmed, even a slightly deviation from the designed strain was observed. It was a negligible small error. Next, we validated the effectiveness of PC12 axonal extension enhancement by two stimulation methodologies, ACMF and the cyclic stretch, under individual and combined stimulation conditions. ACMF showed a best enhancement effect on axonal extension, such as 70 μm at 96 h culture period, which rate is larger than the case of control. On the other hand, the stretch stimulation caused the exfoliation of cells. Hybrid stimulation succeeded to inhibit the exfoliation. However, the extensional rate was less than the case of ACMF. These results can be used to fabricate a bioreactor of nerve cell regeneration.

Cellular Automaton and Finite Element Hybrid Simulation to Predict Axonal Extension Enhancement of Nerve Cell Under Mechanical Stimulation

2018 ◽  
Author(s):  
Shota Takeda ◽  
Yoshihiro Tomita ◽  
Eiji Nakamachi
Keyword(s):  
Finite Element ◽  
Cellular Automaton ◽  
Nerve Cell ◽  
Cell Body ◽  
Mechanical Stimulation ◽  
Morphological Evolution ◽  
Treatment Method ◽  
Cyclic Stretch ◽  
Nerve Network ◽  
Axonal Extension

In the clinical application, the mechanical stimulation against the damaged brain tissue is adopted as the kinesitherapy for the nerve regeneration. Nevertheless, the fundamental mechanism to repair the damaged nerve cell has not been revealed yet. Recently, the cyclic stretch stimulation has been reported as the efficacious treatment method to enhance the axonal extension for regenerative therapy of injured nerve cell. Therefore, we try to develop a new cellular automaton (CA) finite element (FE) hybrid method to predict the axonal extension and nerve network generation, which can evaluate the effect of stretch stimulation on the cell body, axon and dendrites. In the FE results, the stress concentration occurred at the junction of the axon and cell body. The maximum stress value in the axon was 8.2 kPa which is about twice as large as that of the cell body. CA adopted to predict the morphological evolution of nerve cells under the mechanical stimulation. It was confirmed that the stress affects to accelerate the axonal extension as experimentally suggested. As a result, our CAFE can be employed to simulate the axonal extension and generation of nerve network system under the condition of extra cellular mechanical stimulation.

Development of Stretch Stimulation Device for Three-Dimensional Culture of PC12 Cells

2018 ◽  
Author(s):  
Madoka Imura ◽  
Ryota Sakiyama ◽  
Koji Yamamoto ◽  
Yusuke Morita ◽  
Eiji Nakamachi
Keyword(s):  
Pc12 Cells ◽  
Three Dimensional ◽  
Collagen Gel ◽  
3D Cell Culture ◽  
Cyclic Stretch ◽  
Uniform Strain ◽  
Enhancement Effect ◽  
Environmental Stimulation ◽  
Axonal Extension

Enhancement of nerve axonal extension by using the extracellular environmental stimulation were reported. In this study, we focused on the stretch stimulation, and developed a 3D cell culture system to mimic the in vivo extracellular matrices and investigated the fundamental mechanism of axonal extension enhancement. Firstly, we fabricated the stretch stimulation device. The rat phenocromocytoma cells (PC12), the nerve-like cells, embedded in the collagen gel were poured into the stretch chamber. It was set in the stretch stimulation device, which could load the strain to the collagen gel. Secondly, we determined the structure of the stretch chamber to implement the uniform strain distribution in the culture region. Using the finite element (FE) analyses, we confirmed that the uniform strain is assigned in a region of 2.7 × 3.0 × 0.5 mm in the culture region, which is the candidate for the observation region. Thirdly, PC12 cells axonal extension under uniaxial cyclic stretch stimulation (4% strain, 1 Hz) of 24 hours was carried out. After 96 hours’ culture, we observed the 3D morphology of PC12 cells by the multiphoton excitation fluorescence microscope (MPM). Finally, we confirmed the availability of our stretch stimulation device and the enhancement effect of axonal extension.

Tuning the Magnetic Alignment of Cellulose Nanocrystals from Perpendicular to Parallel Using Lepidocrocite Nanoparticles

2019 ◽  
Author(s):  
Valentina Guccini ◽  
Sugam Kumar ◽  
Yulia Trushkina ◽  
Gergely Nagy ◽  
Christina Schütz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Cellulose Nanocrystals ◽  
Small Angle Neutron Scattering ◽  
Lower Amount ◽  
Magnetic Alignment ◽  
Polarized Optical Microscopy ◽  
Parallel Orientation ◽  
Weak Magnetic Fields

The magnetic alignment of cellulose nanocrystals (CNC) and lepidocrocite nanorods (LpN), pristine and in hybrid suspensions has been investigated using contrast-matched small-angle neutron scattering (SANS) under in situ magnetic fields (0 – 6.8 T) and polarized optical microscopy. The pristine CNC (diamagnetic) and pristine LpN (paramagnetic) align perpendicular and parallel to the direction of field, respectively. The alignment of both the nanoparticles in their hybrid suspensions depends on the relative amount of the two components (CNC and LpN) and strength of the applied magnetic field. In the presence of 10 wt% LpN and fields < 1.0 T, the CNC align parallel to the field. In the hybrid containing lower amount of LpN (1 wt%), the ordering of CNC is partially frustrated in all range of magnetic field. At the same time, the LpN shows both perpendicular and parallel orientation, in the presence of CNC. This study highlights that the natural perpendicular ordering of CNC can be switched to parallel by weak magnetic fields and the incorporation of paramagnetic nanoparticle as LpN, as well it gives a method to influence the orientation of LpN.<br>

Aligned Packaging of in-situ Grown CsPbBr3 Nanorods within Polystyrene Nanofibers for Enhanced Polarized Luminescence Properties

2021 ◽  
Author(s):  
Hui Fu ◽  
Huilin Hou ◽  
Zhi Fang ◽  
Chaoyi Chen ◽  
Weiyou Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Luminescence Properties ◽  
Polarized Luminescence

In the present work, we report the strategy for aligned packaging of in-situ grown CsPbBr3 nanorods (NR) within polystyrene (PS) nanofibers (CsPbBr3 NR@PS) based on magnetic field assisted electrospinning for...

A magnetic field in situ measurement method of the heating film in atomic sen

2021 ◽  
pp. 1-1
Author(s):  
Xiaoyang Liang ◽  
Xinxiu Zhou ◽  
Die Hu ◽  
Wenfeng Wu ◽  
Yuchen Jia
Keyword(s):  
Magnetic Field ◽  
Measurement Method ◽  
In Situ Measurement

scholarly journals Titan's exosphere and its interaction with Saturn's magnetosphere

2008 ◽  
Vol 367 (1889) ◽  
pp. 743-752 ◽  
Author(s):  
Iannis Dandouras ◽  
Philippe Garnier ◽  
Donald G Mitchell ◽  
Edmond C Roelof ◽  
Pontus C Brandt ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Remote Sensing ◽  
Charge Exchange ◽  
Mass Spectrometer ◽  
Upper Atmosphere ◽  
Neutral Atoms ◽  
Energetic Ions ◽  
Imaging Instrument ◽  
Singly Charged

Titan's nitrogen-rich atmosphere is directly bombarded by energetic ions, due to its lack of a significant intrinsic magnetic field. Singly charged energetic ions from Saturn's magnetosphere undergo charge-exchange collisions with neutral atoms in Titan's upper atmosphere, or exosphere, being transformed into energetic neutral atoms (ENAs). The ion and neutral camera, one of the three sensors that comprise the magnetosphere imaging instrument (MIMI) on the Cassini/Huygens mission to Saturn and Titan, images these ENAs like photons, and measures their fluxes and energies. These remote-sensing measurements, combined with the in situ measurements performed in the upper thermosphere and in the exosphere by the ion and neutral mass spectrometer instrument, provide a powerful diagnostic of Titan's exosphere and its interaction with the Kronian magnetosphere. These observations are analysed and some of the exospheric features they reveal are modelled.

scholarly journals On the Fluctuation Induced Excess Conductivity in Stainless Steel Sheathed MgB2 Tapes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Suchitra Rajput ◽  
Sujeet Chaudhary
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Stainless Steel ◽  
Coherence Length ◽  
Three Dimensional ◽  
Excess Conductivity ◽  
Scaling Functions ◽  
Critical Fluctuations ◽  
Scaling Models

We report on the analyses of fluctuation induced excess conductivity in the - behavior in the in situ prepared MgB2 tapes. The scaling functions for critical fluctuations are employed to investigate the excess conductivity of these tapes around transition. Two scaling models for excess conductivity in the absence of magnetic field, namely, first, Aslamazov and Larkin model, second, Lawrence and Doniach model, have been employed for the study. Fitting the experimental - data with these models indicates the three-dimensional nature of conduction of the carriers as opposed to the 2D character exhibited by the HTSCs. The estimated amplitude of coherence length from the fitted model is ~21 Å.

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