Validation of a new fluidic device for mechanical stimulation and characterization of microspheres: A first step towards cartilage characterization

Petitjean, Noémie; Dusfour, Gilles; Cañadas, Patrick; Maumus, Marie; Valorge, P.; Dević, Slobodan; Berthelot, Jade; Belamie, Emmanuel; Royer, Pascale; Jørgensen, Christian; Noël, Danièle; Floc’h, Simon Le

doi:10.1016/j.msec.2020.111800

Cited by 2 publications

(14 citation statements)

References 19 publications

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“…All displacements were normalized to micropellet diameter, calculated from the area of the micropellet before applying pressure. As described in a previous study [21], the displacement elds only depend on the ratio of the pressure to the Young's modulus and on the Poisson's ratio. The mean value of the Poisson's ratio of 0.45 was used, as identi ed for 21 days micropellets.…”

Section: Deformation Of Micropellets Caused By Loadingmentioning

confidence: 67%

“…A home-made device, previously validated [21], was used to stimulate the micropellets. Brie y, this is a uidic system, which consists of a 3D-printed tank with 6 conical wells for the concomitant stimulation of 6 micropellets.…”

Section: Mechanical Stimulations 221 Mechanical Loading Devicementioning

confidence: 99%

“…Gene expression was analyzed using the comparative Ct method (2 −ΔΔCt ) after normalization to the housekeeping gene RSP9 and comparison with the nonstimulated control group. An axisymmetric nite element model has previously been created with the software LMGC90 [21]. The numerical model simulates the sinking of a micropellet, represented by half a disk meshed by the software GMSH with 1760 triangles and employing a Neo-Hookean hyperelastic law, in the cone [23].…”

Section: Rt-qpcrmentioning

confidence: 99%

“…Besides generating square signals, we previously reported that constant and cyclical pressure signals can be reliably generated by our device [21]. We therefore evaluated the impact of different types of stimulation signals on chondrocyte gene expression on 21-days micropellets (Fig.…”

Section: Only Dynamic Signals Can Upregulate Chondrocyte Marker Expre...mentioning

confidence: 99%

“…The objective of this study was to mechanically stimulate cartilage micropellets by using a home-made device that has been previously validated for cell-free biomaterial-based microspheres [21]. First, we evaluated the impact of different signal parameters of biomechanical stimulation on the deformation of micropellets and on the expression of ECM-related chondrocyte genes.…”

Section: Introductionmentioning

confidence: 99%

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Complex deformation of cartilage micropellets following mechanical stimulation promotes chondrocyte gene expression

Petitjean

Cañadas

Jørgensen

et al. 2023

Preprint

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Background Articular cartilage (AC)‘s main function is to resist to a stressful mechanical environment and chondrocytes are responding to mechanical stress for the development and homeostasis of this tissue. However, current knowledge on processes involved in response to mechanical stimulation is still limited. These mechanisms are commonly investigated in engineered cartilage models where the chondrocytes are included in an exogeneous biomaterial different from their natural extracellular matrix. The aim of the present study is to better understand the impact of mechanical stimulation on mesenchymal stromal cells (MSCs) derived chondrocytes generated in their own extracellular matrix. Methods A fluidic custom-made device was used for the mechanical stimulation of cartilage micropellets obtained from human MSCs by culture in a chondrogenic medium for 21 days. Six micropellets were positioned into the conical wells of the device chamber and stimulated with different signals of positive pressure (amplitude, frequency and duration). A camera was used to record the sinking of each micropellet into their cone and micropellet deformation was analyzed using a finite element model. Micropellets were harvested at different time points after stimulation for RT-qPCR and histology analysis. Results Moderate micropellet deformation was observed during stimulation with square pressure signals as mean Von Mises strains between 6.39% and 14.35% were estimated for amplitudes of 1.75 to 14 kPa superimposed on a base pressure of 50% of the amplitude. The compression, tension and shear observed during deformation did not alter micropellet microstructure as shown by histological staining. A rapid and transient increase in the expression of chondrocyte markers (SOX9, AGG and COL2B) was measured after a single 30-min stimulation with a square pressure signal of 3.5 kPa amplitude superimposed on a minimum pressure of 1.75 kPa, at 1 Hz. A small change of 1% of cyclical deformations when using a square pressure signal instead of a constant pressure signal induced a great fold change of 2 to 3 of chondrogenic gene expression. Moreover, the expression of fibrocartilage (COL I) or hypertrophic cartilage (COL X, MMP13 and ADAMTS5) was not significantly regulated, except for COL X. ConclusionsOur data demonstrate the interest of fluidic-based compression to stimulate mechanically the growth of cartilage micropellets and set the basis for further investigation of chondrocyte mechanobiology and cartilage-like tissue growth.

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Section: Deformation Of Micropellets Caused By Loadingmentioning

confidence: 67%

Section: Mechanical Stimulations 221 Mechanical Loading Devicementioning

confidence: 99%

Section: Rt-qpcrmentioning

confidence: 99%

Section: Only Dynamic Signals Can Upregulate Chondrocyte Marker Expre...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Complex deformation of cartilage micropellets following mechanical stimulation promotes chondrocyte gene expression

Petitjean

Cañadas

Jørgensen

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

Complex deformation of cartilage micropellets following mechanical stimulation promotes chondrocyte gene expression

Petitjean,

Canadas,

Jorgensen

et al. 2023

Stem Cell Res Ther

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Background Articular cartilage (AC)’s main function is to resist to a stressful mechanical environment, and chondrocytes are responding to mechanical stress for the development and homeostasis of this tissue. However, current knowledge on processes involved in response to mechanical stimulation is still limited. These mechanisms are commonly investigated in engineered cartilage models where the chondrocytes are included in an exogeneous biomaterial different from their natural extracellular matrix. The aim of the present study is to better understand the impact of mechanical stimulation on mesenchymal stromal cells (MSCs)-derived chondrocytes generated in their own extracellular matrix. Methods A fluidic custom-made device was used for the mechanical stimulation of cartilage micropellets obtained from human MSCs by culture in a chondrogenic medium for 21 days. Six micropellets were positioned into the conical wells of the device chamber and stimulated with different signals of positive pressure (amplitude, frequency and duration). A camera was used to record the sinking of each micropellet into their cone, and micropellet deformation was analyzed using a finite element model. Micropellets were harvested at different time points after stimulation for RT-qPCR and histology analysis. Results Moderate micropellet deformation was observed during stimulation with square pressure signals as mean von Mises strains between 6.39 and 14.35% were estimated for amplitudes of 1.75–14 kPa superimposed on a base pressure of 50% of the amplitude. The compression, tension and shear observed during deformation did not alter micropellet microstructure as shown by histological staining. A rapid and transient increase in the expression of chondrocyte markers (SOX9, AGG and COL2B) was measured after a single 30-min stimulation with a square pressure signal of 3.5 kPa amplitude superimposed on a minimum pressure of 1.75 kPa, at 1 Hz. A small change of 1% of cyclical deformations when using a square pressure signal instead of a constant pressure signal induced a fold change of 2 to 3 of chondrogenic gene expression. Moreover, the expression of fibrocartilage (COL I) or hypertrophic cartilage (COL X, MMP13 and ADAMTS5) was not significantly regulated, except for COL X. Conclusions Our data demonstrate that the dynamic deformation of cartilage micropellets by fluidic-based compression modulates the expression of chondrocyte genes responsible for the production of a cartilage-like extracellular matrix. This lays the foundations for further investigating the chondrocyte mechanobiology and the cartilage growth under mechanical stimulation.

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Validation of a new fluidic device for mechanical stimulation and characterization of microspheres: A first step towards cartilage characterization

Abstract: Highlights-A new device was validated to mechanically stimulate and characterize microspheres.-Six microspheres (size 900-1500µm) can be stimulated with various pressure signals.-Biomaterials of various mechanical properties can be stimulated and characterized.

Cited by 2 publications

References 19 publications

Complex deformation of cartilage micropellets following mechanical stimulation promotes chondrocyte gene expression

Complex deformation of cartilage micropellets following mechanical stimulation promotes chondrocyte gene expression

Complex deformation of cartilage micropellets following mechanical stimulation promotes chondrocyte gene expression

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