scholarly journals The effect of frequency in the electrical stimulation of chondrocytes

2020 ◽  
Vol 14 (1) ◽  
pp. 6-18
Author(s):  
Juan Jairo Vaca González ◽  
Juan Felipe Escobar Huertas ◽  
Diego Alexander Garzón Alvarado
Keyword(s):  
Electrical Stimulation ◽  
Electric Fields ◽  
Relevant Information ◽  
Cartilage Explants ◽  
Promising Tool ◽  
Cartilage Injuries ◽  
Molecular Synthesis ◽  
Materials Used ◽  
Regenerative Therapies ◽  
Stimulation Of

Electrical stimulation is a non-invasive therapy used to stimulate chondrocyte dynamics: proliferation, migration, morphology and molecular synthesis. Some studies have evidenced the role of frequency in the generation of electric fields; however, the electrical stimulation sensed by chondrocytes when the frequency varies is not well-documented. Accordingly, a computational model was implemented to assess the frequency dependence of electric fields that stimulate chondrocytes. Cells were modelled in three different scenarios: monolayer cultures, cartilage explants and scaffolds. Chondrocytes were stimulated with 100 Vp-p at frequencies of 0.001, 1, 10, 50, 100 and 1000 kHz. Results showed that frequency is a relevant factor when considering the stimulation of biological samples, since electric fields increased as frequencies were higher. Moreover, chondrocytes experienced different electric fields in both cytoplasm and extracellular environment. This model provides relevant information about the electrical parameters to stimulate cells; in fact, it could enhance experimental procedures, predicting the stimulation that improves chondrocyte dynamics. Electric fields are a promising tool to maintain either well-structured chondrocytes or biomimetic materials used in regenerative therapies such as autologous implantation to treat hyaline cartilage injuries.

scholarly journals Establishment of a New Device for Electrical Stimulation of Non-Degenerative Cartilage Cells In Vitro

2021 ◽  
Vol 22 (1) ◽  
pp. 394
Author(s):  
Simone Krueger ◽  
Alexander Riess ◽  
Anika Jonitz-Heincke ◽  
Alina Weizel ◽  
Anika Seyfarth ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Electric Fields ◽  
Cartilage Tissue ◽  
Type I ◽  
Dependent Manner ◽  
New Device ◽  
Alternating Electric Fields ◽  
Cartilage Cells ◽  
Stimulation Of

In cell-based therapies for cartilage lesions, the main problem is still the formation of fibrous cartilage, caused by underlying de-differentiation processes ex vivo. Biophysical stimulation is a promising approach to optimize cell-based procedures and to adapt them more closely to physiological conditions. The occurrence of mechano-electrical transduction phenomena within cartilage tissue is physiological and based on streaming and diffusion potentials. The application of exogenous electric fields can be used to mimic endogenous fields and, thus, support the differentiation of chondrocytes in vitro. For this purpose, we have developed a new device for electrical stimulation of chondrocytes, which operates on the basis of capacitive coupling of alternating electric fields. The reusable and sterilizable stimulation device allows the simultaneous use of 12 cavities with independently applicable fields using only one main supply. The first parameter settings for the stimulation of human non-degenerative chondrocytes, seeded on collagen type I elastin-based scaffolds, were derived from numerical electric field simulations. Our first results suggest that applied alternating electric fields induce chondrogenic re-differentiation at the gene and especially at the protein level of human de-differentiated chondrocytes in a frequency-dependent manner. In future studies, further parameter optimizations will be performed to improve the differentiation capacity of human cartilage cells.

Electrical stimulation of cell growth and neurogenesis using conductive and nonconductive microfibrous scaffolds

2019 ◽  
Vol 11 (6) ◽  
pp. 264-279
Author(s):  
Simon Grossemy ◽  
Peggy P Y Chan ◽  
Pauline M Doran
Keyword(s):  
Electrical Stimulation ◽  
Cell Growth ◽  
Electric Fields ◽  
Neural Differentiation ◽  
Culture Medium ◽  
Sheet Resistivity ◽  
Differentiation Markers ◽  
Cytotoxic Effects ◽  
Neurite Development ◽  
Stimulation Of

Abstract The effect of exogenous electrical stimulation on cell viability, attachment, growth, and neurogenesis was examined using PC12 cells in microfibrous viscose-rayon scaffolds immersed in culture medium. The scaffolds were applied either in their nonconductive state or after coating the fibres with 200 nm of gold to give a scaffold sheet resistivity of (13 ± 1.3) Ω square−1. The cells were treated for 12 days using direct current electrical stimulation of 2 h per day. No cytotoxic effects were observed when up to 500 mV (8.3 mV mm−1) was applied to the scaffolds without gold, or when up to 100 mV (1.7 mV mm−1) was applied to the scaffolds with gold. Compared with unstimulated cells, whereas electrical stimulation significantly enhanced cell growth and attachment in the nonconductive scaffolds without gold, similar effects were not found for the conductive scaffolds with gold. Neural differentiation in the presence of nerve growth factor was improved by electrical stimulation in both scaffolds; however, neurite development and the expression of key differentiation markers were greater in the nonconductive scaffolds without gold than in the scaffolds with gold. Application of the same current to scaffolds with and without gold led to much higher levels of neurogenesis in the scaffolds without gold. This work demonstrates that substantial benefits in terms of cell growth and neural differentiation can be obtained using electric fields exerted across nonconductive microfibrous scaffolds, and that this approach to electrical stimulation can be more effective than when the stimulus is applied to cells on conductive scaffolds.

scholarly journals Multi-channel transorbital electrical stimulation for effective stimulation of posterior retina

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sangjun Lee ◽  
Jimin Park ◽  
Jinuk Kwon ◽  
Dong Hwan Kim ◽  
Chang-Hwan Im
Keyword(s):  
Electrical Stimulation ◽  
Electric Field ◽  
Electric Fields ◽  
Anterior Part ◽  
Posterior Part ◽  
Human Head ◽  
Electrical Current ◽  
Field Analysis ◽  
Head Model ◽  
Stimulation Of

AbstractTransorbital electrical stimulation (tES) has been studied as a new noninvasive method for treating intractable eye diseases by delivering weak electrical current to the eye through a pair of electrodes attached to the skin around the eye. Studies have reported that the therapeutic effect of tES is determined by the effective stimulation of retinal cells that are densely distributed in the posterior part of the retina. However, in conventional tES with a pair of electrodes, a greater portion of the electric field is delivered to the anterior part of the retina. In this study, to address this issue, a new electrode montage with multiple electrodes was proposed for the effective delivery of electric fields to the posterior retina. Electric field analysis based on the finite element method was performed with a realistic human head model, and optimal injection currents were determined using constrained convex optimization. The resultant electric field distributions showed that the proposed multi-channel tES enables a more effective stimulation of the posterior retina than the conventional tES with a pair of electrodes.

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