Devices and Techniques for in Vitro Mechanical Stimulation of Bone Cells

2001 ◽  
pp. 723-744 ◽  
Keyword(s):  
Mechanical Stimulation ◽  
Bone Cells ◽  
Stimulation Of

scholarly journals A Novel Bioreactor for the Mechanical Stimulation of Clinically Relevant Scaffolds for Muscle Tissue Engineering Purposes

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 474
Author(s):  
Silvia Todros ◽  
Silvia Spadoni ◽  
Edoardo Maghin ◽  
Martina Piccoli ◽  
Piero G. Pavan
Keyword(s):  
Mechanical Stimulation ◽  
Strain Range ◽  
Tensile Tests ◽  
Muscular Tissue ◽  
Fe Model ◽  
Mechanical Stimuli ◽  
Physiological Strain ◽  
Cellular Alignment ◽  
Stimulation Of

Muscular tissue regeneration may be enhanced in vitro by means of mechanical stimulation, inducing cellular alignment and the growth of functional fibers. In this work, a novel bioreactor is designed for the radial stimulation of porcine-derived diaphragmatic scaffolds aiming at the development of clinically relevant tissue patches. A Finite Element (FE) model of the bioreactor membrane is developed, considering two different methods for gripping muscular tissue patch during the stimulation, i.e., suturing and clamping with pliers. Tensile tests are carried out on fresh and decellularized samples of porcine diaphragmatic tissue, and a fiber-reinforced hyperelastic constitutive model is assumed to describe the mechanical behavior of tissue patches. Numerical analyses are carried out by applying pressure to the bioreactor membrane and evaluating tissue strain during the stimulation phase. The bioreactor designed in this work allows one to mechanically stimulate tissue patches in a radial direction by uniformly applying up to 30% strain. This can be achieved by adopting pliers for tissue clamping. Contrarily, the use of sutures is not advisable, since high strain levels are reached in suturing points, exceeding the physiological strain range and possibly leading to tissue laceration. FE analysis allows the optimization of the bioreactor configuration in order to ensure an efficient transduction of mechanical stimuli while preventing tissue damage.

scholarly journals Mechanical stimulation of human dermal fibroblasts regulates pro-inflammatory cytokines: potential insight into soft tissue manual therapies

2020 ◽  
Author(s):  
Aric Anloague ◽  
Aaron Mahoney ◽  
Oladipupo Ogunbekun ◽  
William R. Thompson ◽  
Bryan Larsen ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Inflammatory Cytokines ◽  
Mechanical Stimulation ◽  
Mechanical Strain ◽  
Dermal Fibroblasts ◽  
Manual Therapies ◽  
Human Dermal Fibroblasts ◽  
Stimulation Of ◽  
Pro Inflammatory Cytokines

Abstract Objective Soft tissue manual therapies are commonly utilized by osteopathic physicians, chiropractors, physical therapists and massage therapists. These techniques are predicated on subjecting tissues to biophysical mechanical stimulation but the cellular and molecular mechanism(s) mediating these effects are poorly understood. A series of previous studies established an in vitro model system for examining mechanical stimulation of dermal fibroblasts and established that repetitive strain, intended to mimic overuse injury, induces the secretion of numerous pro-inflammatory cytokines. Moreover, mechanical strain intended to mimic soft tissue manual therapy reduces strain-induced secretion of pro-inflammatory cytokines. Here, we sought to partially confirm and extend these reports and provide independent corroboration of prior results. Results Using cultures of primary human dermal fibroblasts, we confirm mechanical forces intended to mimic repetitive motion strain increases levels of IL-6 and that mechanical strain intended to mimic therapeutic soft tissue stimulation reduces IL-6 levels. We also extend the prior work, reporting that therapy-like mechanical stimulation reduces levels of IL-8. Although there are important limitations to this experimental model, these findings provide supportive evidence that therapeutic soft tissue massage may reduce inflammation. Future work is required to address these open questions and advance the mechanistic understanding of therapeutic soft tissue stimulation.

Multiscale Modeling of Trabecular Bone Marrow: Understanding the Micromechanical Environment of Mesenchymal Stem Cells During Osteoporosis

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
T. J. Vaughan ◽  
M. Voisin ◽  
G. L. Niebur ◽  
L. M. McNamara
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Trabecular Bone ◽  
Mechanical Stimulation ◽  
Cell Level ◽  
Mechanical Environment ◽  
Stimulation Of

Mechanical loading directs the differentiation of mesenchymal stem cells (MSCs) in vitro and it has been hypothesized that the mechanical environment plays a role in directing the cellular fate of MSCs in vivo. However, the complex multicellular composition of trabecular bone marrow means that the precise nature of mechanical stimulation that MSCs experience in their native environment is not fully understood. In this study, we developed a multiscale model that discretely represents the cellular constituents of trabecular bone marrow and applied this model to characterize mechanical stimulation of MCSs in vivo. We predicted that cell-level strains in certain locations of the trabecular marrow microenvironment were greater in magnitude (maximum ε12 = ∼24,000 με) than levels that have been found to result in osteogenic differentiation of MSCs in vitro (>8000 με), which may indicate that the native mechanical environment of MSCs could direct cellular fate in vivo. The results also showed that cell–cell adhesions could play an important role in mediating mechanical stimulation within the MSC population in vivo. The model was applied to investigate how changes that occur during osteoporosis affected mechanical stimulation in the cellular microenvironment of trabecular bone marrow. Specifically, a reduced bone volume (BV) resulted in an overall increase in bone deformation, leading to greater cell-level mechanical stimulation in trabecular bone marrow (maximum ε12 = ∼48,000 με). An increased marrow adipocyte content resulted in slightly lower levels of stimulation within the adjacent cell population due to a shielding effect caused by the more compliant behavior of adipocytes (maximum ε12 = ∼41,000 με). Despite this reduction, stimulation levels in trabecular bone marrow during osteoporosis remained much higher than those predicted to occur under healthy conditions. It was found that compensatory mechanobiological responses that occur during osteoporosis, such as increased trabecular stiffness and axial alignment of trabeculae, would be effective in returning MSC stimulation in trabecular marrow to normal levels. These results have provided novel insight into the mechanical stimulation of the trabecular marrow MSC population in both healthy and osteoporotic bone, and could inform the design three-dimensional (3D) in vitro bioreactor strategies techniques, which seek to emulate physiological conditions.

Mechanical stimulation of neurites generates an inward current in putative aortic baroreceptor neurons in vitro

1997 ◽  
Vol 757 (1) ◽  
pp. 149-154 ◽  
Author(s):  
J.Thomas Cunningham ◽  
Ruth E Wachtel ◽  
François M Abboud
Keyword(s):  
Mechanical Stimulation ◽  
Inward Current ◽  
Stimulation Of

scholarly journals Mechanically stimulated ATP release from murine bone cells is regulated by a balance of injury and repair

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Nicholas Mikolajewicz ◽  
Elizabeth A Zimmermann ◽  
Bettina M Willie ◽  
Svetlana V Komarova
Keyword(s):  
Mechanical Stimulation ◽  
Cell Injury ◽  
Bone Cells ◽  
Atp Release ◽  
Membrane Repair ◽  
Membrane Injury ◽  
Vesicular Release ◽  
Injury And Repair

Bone cells sense and actively adapt to physical perturbations to prevent critical damage. ATP release is among the earliest cellular responses to mechanical stimulation. Mechanical stimulation of a single murine osteoblast led to the release of 70 ± 24 amole ATP, which stimulated calcium responses in neighboring cells. Osteoblasts contained ATP-rich vesicles that were released upon mechanical stimulation. Surprisingly, interventions that promoted vesicular release reduced ATP release, while inhibitors of vesicular release potentiated ATP release. Searching for an alternative ATP release route, we found that mechanical stresses induced reversible cell membrane injury in vitro and in vivo. Ca2+/PLC/PKC-dependent vesicular exocytosis facilitated membrane repair, thereby minimizing cell injury and reducing ATP release. Priming cellular repair machinery prior to mechanical stimulation reduced subsequent membrane injury and ATP release, linking cellular mechanosensitivity to prior mechanical exposure. Thus, our findings position ATP release as an integrated readout of membrane injury and repair.

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