Piconewton Level Loading and Sub-Cellular Deformation of Bone Cells Using a Novel Stokesian Fluid Stimulus Probe (SFSP)

2011 ◽  
Author(s):  
Danielle Wu ◽  
Peter Ganatos ◽  
Sheldon Weinbaum ◽  
David C. Spray
Keyword(s):  
Fluid Flow ◽  
Bone Cells ◽  
Cell Process ◽  
Cellular Polarity ◽  
Attachment Sites ◽  
Tensile Forces ◽  
Stimulus Probe ◽  
Level Loading

A new quantifiable in vitro force probe, the Stokesian Fluid Stimulus Probe (SFSP), is developed to hydrodynamically stimulate local regions of the osteocyte whereby neither antibody decoration nor probe membrane perturbation is necessary. Osteocytes are imbedded in hard mineralized matrix where single-cell, in vivo experimentation is extremely challenging. Whole bone tissue loading induces cyclic fluid flow throughout the bone porosity to hydrodynamically load osteocytic networks within the lacunar-canalicular-system (LCS). A theoretical model has been developed to describe the fluid flow through the dynamic and structurally complex microenvironment surrounding the osteocytic network within the LCS. The model predicts tensile forces of 1–10pN to occur at discrete attachment sites connecting the osteocyte cell process to canalicular wall projections during physiological loading1. Our new force probe’s design and implementation has successfully 1) reproduced in vivo level forces at subcellular precision to assess cellular polarity in vitro and 2) demonstrated that cellular signaling is initiated at integrin attachment sites along the cell process.

scholarly journals A fluid–structure interaction model to characterize bone cell stimulation in parallel-plate flow chamber systems

2013 ◽  
Vol 10 (81) ◽  
pp. 20120900 ◽  
Author(s):  
T. J. Vaughan ◽  
M. G. Haugh ◽  
L. M. McNamara
Keyword(s):  
Shear Stress ◽  
Fluid Flow ◽  
Parallel Plate ◽  
Bone Cells ◽  
Mechanical Stimulus ◽  
Flow Chamber ◽  
Parallel Plate Flow Chamber ◽  
Structure Interaction

Bone continuously adapts its internal structure to accommodate the functional demands of its mechanical environment and strain-induced flow of interstitial fluid is believed to be the primary mediator of mechanical stimuli to bone cells in vivo. In vitro investigations have shown that bone cells produce important biochemical signals in response to fluid flow applied using parallel-plate flow chamber (PPFC) systems. However, the exact mechanical stimulus experienced by the cells within these systems remains unclear. To fully understand this behaviour represents a most challenging multi-physics problem involving the interaction between deformable cellular structures and adjacent fluid flows. In this study, we use a fluid–structure interaction computational approach to investigate the nature of the mechanical stimulus being applied to a single osteoblast cell under fluid flow within a PPFC system. The analysis decouples the contribution of pressure and shear stress on cellular deformation and for the first time highlights that cell strain under flow is dominated by the pressure in the PPFC system rather than the applied shear stress. Furthermore, it was found that strains imparted on the cell membrane were relatively low whereas significant strain amplification occurred at the cell–substrate interface. These results suggest that strain transfer through focal attachments at the base of the cell are the primary mediators of mechanical signals to the cell under flow in a PPFC system. Such information is vital in order to correctly interpret biological responses of bone cells under in vitro stimulation and elucidate the mechanisms associated with mechanotransduction in vivo .

Fluid-Structure Interaction Modelling Predicts That Strain Transfer Through Focal Attachments of Osteoblast Cells are the Primary Mediators of Mechanical Stimulation Under Fluid Flow

2013 ◽  
Author(s):  
T. J. Vaughan ◽  
M. G. Haugh ◽  
L. M. McNamara
Keyword(s):  
Fluid Flow ◽  
Mechanical Stimulation ◽  
Interstitial Fluid ◽  
Bone Cells ◽  
Mechanical Stimulus ◽  
Mechanical Stimuli ◽  
Interstitial Fluid Flow ◽  
Interaction Modelling

Bone continuously adapts its internal structure to accommodate the functional demands of its mechanical environment. It has been proposed that indirect strain-induced flow of interstitial fluid surrounding bone cells may be the primary mediator of mechanical stimuli in-vivo [1]. Due to the practical difficulties in ascertaining whether interstitial fluid flow is indeed the primary mediator of mechanical stimuli in the in vivo environment, much of the evidence supporting this theory has been established through in vitro investigations that have observed cellular activity in response to fluid flow imposed by perfusion chambers [2]. While such in vitro experiments have identified key mechanisms involved in the mechanotransduction process, the exact mechanical stimulus being imparted to cells within a monolayer is unknown [3]. Furthermoreit is not clear whether the mechanical stimulation is comparable between different experimental systems or, more importantly, is representative of physiological loading conditions experienced by bone cells in vivo.

scholarly journals O23: CHARACTERISING PATIENT-DERIVED COLORECTAL CANCER TISSUE-ORIGINATED ORGANOIDAL SPHEROIDS FOR HIGH-THROUGHPUT MICROFLUIDIC APPLICATIONS

2021 ◽  
Vol 108 (Supplement_1) ◽  
Author(s):  
MI Khot ◽  
M Levenstein ◽  
R Coppo ◽  
J Kondo ◽  
M Inoue ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fluid Flow ◽  
High Throughput ◽  
Microfluidic Devices ◽  
In Vitro Models ◽  
Fluorescent Imaging ◽  
Cancer Tissue ◽  
Cell Models

Abstract Introduction Three-dimensional (3D) cell models have gained reputation as better representations of in vivo cancers as compared to monolayered cultures. Recently, patient tumour tissue-derived organoids have advanced the scope of complex in vitro models, by allowing patient-specific tumour cultures to be generated for developing new medicines and patient-tailored treatments. Integrating 3D cell and organoid culturing into microfluidics, can streamline traditional protocols and allow complex and precise high-throughput experiments to be performed with ease. Method Patient-derived colorectal cancer tissue-originated organoidal spheroids (CTOS) cultures were acquired from Kyoto University, Japan. CTOS were cultured in Matrigel and stem-cell media. CTOS were treated with 5-fluorouracil and cytotoxicity evaluated via fluorescent imaging and ATP assay. CTOS were embedded, sectioned and subjected to H&E staining and immunofluorescence for ABCG2 and Ki67 proteins. HT29 colorectal cancer spheroids were produced on microfluidic devices using cell suspensions and subjected to 5-fluorouracil treatment via fluid flow. Cytotoxicity was evaluated through fluorescent imaging and LDH assay. Result 5-fluorouracil dose-dependent reduction in cell viability was observed in CTOS cultures (p<0.01). Colorectal CTOS cultures retained the histology, tissue architecture and protein expression of the colonic epithelial structure. Uniform 3D HT29 spheroids were generated in the microfluidic devices. 5-fluorouracil treatment of spheroids and cytotoxic analysis was achieved conveniently through fluid flow. Conclusion Patient-derived CTOS are better complex models of in vivo cancers than 3D cell models and can improve the clinical translation of novel treatments. Microfluidics can streamline high-throughput screening and reduce the practical difficulties of conventional organoid and 3D cell culturing. Take-home message Organoids are the most advanced in vitro models of clinical cancers. Microfluidics can streamline and improve traditional laboratory experiments.

scholarly journals Matrix Vesicles: Role in Bone Mineralization and Potential Use as Therapeutics

2021 ◽  
Vol 14 (4) ◽  
pp. 289
Author(s):  
Sana Ansari ◽  
Bregje W. M. de de Wildt ◽  
Michelle A. M. Vis ◽  
Carolina E. de de Korte ◽  
Keita Ito ◽  
...  
Keyword(s):  
Bone Formation ◽  
Bone Regeneration ◽  
Bone Cells ◽  
Bone Mineralization ◽  
Recipient Cell ◽  
Organic Matrix ◽  
Matrix Vesicles ◽  
Matrix Mineralization

Bone is a complex organ maintained by three main cell types: osteoblasts, osteoclasts, and osteocytes. During bone formation, osteoblasts deposit a mineralized organic matrix. Evidence shows that bone cells release extracellular vesicles (EVs): nano-sized bilayer vesicles, which are involved in intercellular communication by delivering their cargoes through protein–ligand interactions or fusion to the plasma membrane of the recipient cell. Osteoblasts shed a subset of EVs known as matrix vesicles (MtVs), which contain phosphatases, calcium, and inorganic phosphate. These vesicles are believed to have a major role in matrix mineralization, and they feature bone-targeting and osteo-inductive properties. Understanding their contribution in bone formation and mineralization could help to target bone pathologies or bone regeneration using novel approaches such as stimulating MtV secretion in vivo, or the administration of in vitro or biomimetically produced MtVs. This review attempts to discuss the role of MtVs in biomineralization and their potential application for bone pathologies and bone regeneration.

TRENDS AND CHALLENGES OF CARTILAGE TISSUE ENGINEERING

2009 ◽  
Vol 21 (03) ◽  
pp. 149-155 ◽  
Author(s):  
Hsu-Wei Fang
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Growth Factors ◽  
Bone Cells ◽  
Cartilage Tissue Engineering ◽  
Bioactive Molecules ◽  
In Vivo Studies ◽  
Cartilage Tissue

Cartilage injuries may be caused by trauma, biomechanical imbalance, or degenerative changes of joint. Unfortunately, cartilage has limited capability to spontaneous repair once damaged and may lead to progressive damage and degeneration. Cartilage tissue-engineering techniques have emerged as the potential clinical strategies. An ideal tissue-engineering approach to cartilage repair should offer good integration into both the host cartilage and the subchondral bone. Cells, scaffolds, and growth factors make up the tissue engineering triad. One of the major challenges for cartilage tissue engineering is cell source and cell numbers. Due to the limitations of proliferation for mature chondrocytes, current studies have alternated to use stem cells as a potential source. In the recent years, a lot of novel biomaterials has been continuously developed and investigated in various in vitro and in vivo studies for cartilage tissue engineering. Moreover, stimulatory factors such as bioactive molecules have been explored to induce or enhance cartilage formation. Growth factors and other additives could be added into culture media in vitro, transferred into cells, or incorporated into scaffolds for in vivo delivery to promote cellular differentiation and tissue regeneration.Based on the current development of cartilage tissue engineering, there exist challenges to overcome. How to manipulate the interactions between cells, scaffold, and signals to achieve the moderation of implanted composite differentiate into moderate stem cells to differentiate into hyaline cartilage to perform the optimum physiological and biomechanical functions without negative side effects remains the target to pursue.

scholarly journals Protocol of Co-Culture of Human Osteoblasts and Osteoclasts to Test Biomaterials for Bone Tissue Engineering

2022 ◽  
Vol 5 (1) ◽  
pp. 8
Author(s):  
Giorgia Borciani ◽  
Giorgia Montalbano ◽  
Nicola Baldini ◽  
Chiara Vitale-Brovarone ◽  
Gabriela Ciapetti
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Bone Cells ◽  
Bone Cell ◽  
Seeding Density ◽  
Bone Homeostasis ◽  
Bone Microenvironment

New biomaterials and scaffolds for bone tissue engineering (BTE) applications require to be tested in a bone microenvironment reliable model. On this assumption, the in vitro laboratory protocols with bone cells represent worthy experimental systems improving our knowledge about bone homeostasis, reducing the costs of experimentation. To this day, several models of the bone microenvironment are reported in the literature, but few delineate a protocol for testing new biomaterials using bone cells. Herein we propose a clear protocol to set up an indirect co-culture system of human-derived osteoblasts and osteoclast precursors, providing well-defined criteria such as the cell seeding density, cell:cell ratio, the culture medium, and the proofs of differentiation. The material to be tested may be easily introduced in the system and the cell response analyzed. The physical separation of osteoblasts and osteoclasts allows distinguishing the effects of the material onto the two cell types and to evaluate the correlation between material and cell behavior, cell morphology, and adhesion. The whole protocol requires about 4 to 6 weeks with an intermediate level of expertise. The system is an in vitro model of the bone remodeling system useful in testing innovative materials for bone regeneration, and potentially exploitable in different application fields. The use of human primary cells represents a close replica of the bone cell cooperation in vivo and may be employed as a feasible system to test materials and scaffolds for bone substitution and regeneration.

In Vitro Experimental Investigation of the Integrity of the Stem–Cement Interface

2013 ◽  
Vol 647 ◽  
pp. 53-56
Author(s):  
Hong Yu Zhang ◽  
Leigh Fleming ◽  
Liam Blunt
Keyword(s):  
Experimental Investigation ◽  
Fluid Flow ◽  
Hip Replacement ◽  
Hip Prosthesis ◽  
Vitro Experiment ◽  
Cement Interface ◽  
In Vitro Experiment ◽  
Mechanical Bonding

The rationale behind failure of cemented total hip replacement is still far from being well understood in a mechanical and molecular perspective. In the present study, the integrity of the stem–cement interface was investigated through an in vitro experiment monitoring fluid flow along this interface. The results indicated that a good mechanical bonding formed at the stem–cement interface before debonding of this interface was induced by physiological loadings during the in vivo service of the hip prosthesis.

scholarly journals Increased Bone Mass in Mice Lacking the Adipokine Apelin

Endocrinology ◽  
2013 ◽  
Vol 154 (6) ◽  
pp. 2069-2080 ◽  
Author(s):  
Lalita Wattanachanya ◽  
Wei-Dar Lu ◽  
Ramendra K. Kundu ◽  
Liping Wang ◽  
Marcia J. Abbott ◽  
...  
Keyword(s):  
Bone Mass ◽  
Bone Cells ◽  
Physiological Role ◽  
In Vitro Study ◽  
Maximum Effect ◽  
Dependent Manner ◽  
Primary Mouse ◽  
Skeletal Homeostasis

Abstract Adipose tissue plays an important role in skeletal homeostasis, and there is interest in identifying adipokines that influence bone mass. One such adipokine may be apelin, a ligand for the Gi-G protein-coupled receptor APJ, which has been reported to enhance mitogenesis and suppress apoptosis in MC3T3-E1 cells and primary human osteoblasts (OBs). However, it is unclear whether apelin plays a physiological role in regulating skeletal homeostasis in vivo. In this study, we compared the skeletal phenotypes of apelin knockout (APKO) and wild-type mice and investigated the direct effects of apelin on bone cells in vitro. The increased fractional cancellous bone volume at the distal femur was observed in APKO mice of both genders at 12 weeks of age and persisted until the age of 20. Cortical bone perimeter at the femoral midshaft was significantly increased in males and females at both time points. Dynamic histomorphometry revealed that APKO mice had increased rates of bone formation and mineral apposition, with evidences of accelerated OB proliferation and differentiation, without significant alteration in osteoclast activity. An in vitro study showed that apelin increased proliferation of primary mouse OBs as well as suppressed apoptosis in a dose-dependent manner with the maximum effect at 5nM. However, it had no effect on the formation of mineralized nodules. We did not observed significantly altered in osteoclast parameters in vitro. Taken together, the increased bone mass in mice lacking apelin suggested complex direct and paracrine/endocrine effects of apelin on bone, possibly via modulating insulin sensitivity. These results indicate that apelin functions as a physiologically significant antianabolic factor in bone in vivo.

Fabrication of amorphous strontium polyphosphate microparticles that induce mineralization of bone cells in vitro and in vivo

2017 ◽  
Vol 50 ◽  
pp. 89-101 ◽  
Author(s):  
Werner E.G. Müller ◽  
Emad Tolba ◽  
Maximilian Ackermann ◽  
Meik Neufurth ◽  
Shunfeng Wang ◽  
...  
Keyword(s):  
Bone Cells

In vivo and in vitro study of enamel fluid flow in human premolars

2020 ◽  
Vol 117 ◽  
pp. 104795 ◽  
Author(s):  
Rathirach Tanapitchpong ◽  
Ekachai Chunhacheevachaloke ◽  
Orapin Ajcharanukul
Keyword(s):  
Fluid Flow ◽  
In Vitro Study ◽  
Vitro Study
Sign in / Sign up

Export Citation Format

Share Document