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1.
Journal of Medical Biomechanics ; (6): E402-E407, 2023.
Article in Chinese | WPRIM | ID: wpr-987965

ABSTRACT

The peripheral vestibular organs are sensors for linear acceleration (gravity and head tilt) and rotation,and turn them into nerve signals that travel to the central nervous system to regulate physiological functions, which play an important role in regulating body stability, ocular movement, autonomic nerve activity, arterial pressure, body temperature, as well as muscle and bone metabolism. The effect of gravity on these functions can be attributed to high plasticity of the vestibular system. In this review, changes in vestibular-related physiological functions induced by the hypergravity and microgravity were introduced, including arterial pressure,muscle and bone metabolism, feeding behavior and body temperature, with the aim to better understand the physiological function of vestibular in adaption to special gravity environment.

2.
Journal of Medical Biomechanics ; (6): E465-E471, 2021.
Article in Chinese | WPRIM | ID: wpr-904425

ABSTRACT

Prosthetic loosening and periprosthetic inflammation, as serious complications after joint replacement surgery, often require the secondary surgery for repair, which is easy to adversely affect the physical/mental health and economic status of patients.Studies have shown that the functional phenotype expressed by macrophages by different stimuli, namely macrophage polarization state, prolonged M1 polarization can lead to the continuation of long-term inflammation, while timely and effective M2 macrophage phenotype will lead to enhanced osteogenesis and tissue remodeling cytokine secretion and subsequent osseointegration, which play a crucial role in the development and outcome of prosthetic loosening and periprosthetic inflammation.The local micro-environment of extracellular matrix (ECM) is an important factor in the activation, migration, proliferation and fusion of macrophages. Researchers have deeply understood it mainly through the crosstalk between surface properties of biomaterials and macrophages. As an effector cell, macro-phages can perform complex spatiotemporal cellular functional responses by sensing the physical and chemical environment (surface topography, wettability, chemical composition, biological proteins) represented by surface properties of biomaterials.This paper summarizes the recent findings on macrophage polarization and material surface properties.

3.
Journal of Medical Biomechanics ; (6): E035-E042, 2020.
Article in Chinese | WPRIM | ID: wpr-804507

ABSTRACT

Objective To investigate the effect of microgravity on MC3T3-E1 osteoblast differentiation. Methods The differential miRNA and mRNA expression profiling of MC3T3-E1 cells during exposure to microgravity were established by RNA transcriptome sequencing technology (RNA-seq). The RNA sequencing results were validated using quantitative real-time polymerase chain reaction (q-PCR). Bioinformatic analyses were applied for further study of these differentially expressed miRNAs and mRNAs. Results Compared with control (CON) group, A total of 1 912 coding transcripts and 160 miRNAs were detected along with osteogenic differentiation in simulated microgravity (SMG) group. Bioinformatic analysis revealed 10 core regulatory genes including 7 mRNAs and 3 miRNAs. Based on the analysis and verification, one miRNA, miR-9_6666-5p, was identified, which might play an important role in osteogenic differentiation process under microgravity. Conclusions The process of osteoblast differentiation was repressed under microgravity which might be related to the changed expression profile of miRNA/mRNA. The research findings can contribute to the better understanding of the molecular mechanisms of mRNA and miRNAs in osteogenic differentiation and bone formation under the microgravity condition.

4.
Chinese Journal of Orthopaedics ; (12): 362-371, 2020.
Article in Chinese | WPRIM | ID: wpr-868978

ABSTRACT

Objective:To establish a hypergravity loading model with a high-acceleration centrifugal loading device and to investigate the effects of different hypergravity loading and icariin on osteoblast adhesion and cytoskeleton.Methods:MC3T3-E1 cells were seeded in the dishes of cell culture at a density of 2×10 5/cm 2. And the experiment was divided into 6 groups: control group (without icariin and loading); simple administration group (only icariin); 10 G loading group (only loading); 10 G administration group (with icariin and loading); 40 G loading group (only loading); 40 G administration group (with icariin and loading). The experimental loading group was loaded with MC3T3-E1 cells using a high-acceleration centrifugal loader. And continuous loading for 3 d, 30 min per d. The control group and the simple administration group were exposed to normal gravity, and the remaining conditions were not different from the experimental group. Icariin was used at a concentration of 10 -7 mol/L in all administration groups, and the experiments were carried out according to the method of preventive administration. At the same time, the related molecular biological techniques such as alizarin red staining, alkaline phosphatase (ALP) activity measurement, CCK-8 cell proliferation experiment, cytoskeleton phalloidin staining, qPCR and Western Blot were used to detect the effects of icariin on osteoblasts adhesion protein integrin α5 and integrin β1 and cytoskeleton protein F-actin under hypergravity extreme mechanical environment. Results:All models were successfully prepared. The alizarin red staining: The icariin could significantly promote the formation of osteoblastic calcified nodules. And the 10 G loading could also promote the mineralization of osteoblasts and increase the number of mineralized nodules, while the mineralization and the number of mineralized nodules of osteoblasts are significantly reduced in 40 G loading. ALP activity test: The OD values of simple administration group, 10 G loading group and 40 G loading group were 0.246, 0.331 and 0.163, respectively. Compared with 0.207 in the control group, the differences were statistically significant ( P<0.05). The 10 G administration group and the 40 G administration group were 0.373 and 0.180, and the differences were statistically significant ( P<0.05). The results of CCK-8 proliferation experiments: The OD value of simple administration group were 0.650, which was statistically significant compared with 0.551 of control group ( P=0.031). The 10 G loading group and 40 G loading group were 1.193 and 0.245, and their differences with the control group were both statistically significant ( P<0.05). The OD value of 10G administration group and the 40 G administration group were 1.300 and 0.310, which were significantly different from the respective loading groups ( P<0.05). Phalloidin staining: 10 G loading significantly increased the number of cells, but the changes in cells morphology and skeleton were not obvious. 40 G loading significantly inhibited the increase of the number of cells, meanwhile, made the pseudopods of cells more shorter and even disappeared. 40 G loading made the seriously damage of the cytoskeleton and even cause the cells to death. Icariin had no effect on the cells morphology, but it did has a certain repair effect after the cells loading. The results of qPCR and Western Blot experiments all confirmed that the expressions of integrin α5, integrin β1 and F-actin were up-regulated after icariin treatment. 10 G loading could promote the expression of integrin α5, integrin β1 and F-actin, and 40 G loading significantly inhibited the expression of the mRNA and proteins. Conclusion:Both 10 G condition and icariin can promote the development, cell adhesion and the cytoskeleton's stability of osteoblasts, while 40 G has a significant inhibitory effect.

5.
Journal of Medical Biomechanics ; (6): E636-E642, 2020.
Article in Chinese | WPRIM | ID: wpr-862358

ABSTRACT

With the development of the 3rd-generation high-throughput sequencing technology and tissue engineering, recent studies show that many long-chain non-coding RNAs (LncRNAs) have played an important role in osteogenic differentiation of mesenchymal stem cells (MSCs). LncRNAs, which are involved in the regulation of mechanical regulation, further regulate bone-related cell functions and play a regulatory role at multiple levels, including transcription, post-transcriptional and epigenetic. LncRNAs may be involved in the osteogenic differentiation and bone remodeling of MSCs, the regulation of bone-related cell functions as a mechanical response molecule, as well as the pathological process of skeletal diseases.

6.
Journal of Medical Biomechanics ; (6): E568-E573, 2020.
Article in Chinese | WPRIM | ID: wpr-862348

ABSTRACT

Objective To design a novel strain loading device for studying the mechanical biology of adherent cells. Methods Based on the technology of substrate deformation loading, the device adopted controllable stepper to cause deformation of the silastic chamber, so as to realize cell loading with multiple units and large strain. The device was developed to test its loading functions. The three-dimensional (3D) models of the silastic chamber were established to simulate the loaded chamber by the finite element technology, and uniformity of the strain field was analyzed. The device applied 5% strain to bone marrow stromal cells (BMSCs) with 0.5 Hz stretch frequency at 2 hours per day for 5 days, and an inverted phase contrast microscope was used to observe the morphology of BMSCs. Results The developed strain loading device for adherent cells in vitro could provide mechanical unidirectional strain up to 50% with three groups of cell loading substrates; within the 10% stain range, the area of uniform strain filed on the silastic chamber remained above 50%, which ensured that the cells were loaded evenly; the morphology of BMSCs was obviously altered, and the direction of arrangement tended to be perpendicular to the loading direction of principal strain. Conclusions The device shows the advantages of reliable operation, wide strain range, adjustable frequency and convenient operation. It can be used to load multiple cell culture substrates at the same time, which provides convenient conditions for the study of cell mechanobiology.

7.
Journal of Medical Biomechanics ; (6): E434-E439, 2019.
Article in Chinese | WPRIM | ID: wpr-802478

ABSTRACT

As the main organ of the body, the load-bearing ability of bone is closely connected to its biomechanical properties. Bone is a complex hierarchical biomaterial, whose biomechanical properties are determined by its own structure and biological characteristics. Because of its mechanical adaptability, bone tissues represent different biomechanical properties under different mechanical loading. To quantify the complicated properties of bone and provide an accurate theoretical basis for clinical research, it is necessary to give insight into the biomechanical properties of bone at different levels and the constitutive relationships of bone tissues. In this review, relative researches on constitutive relationships in recent years were summarized based on its hierarchical biomechanical properties.

8.
Journal of Medical Biomechanics ; (6): E623-E630, 2019.
Article in Chinese | WPRIM | ID: wpr-802403

ABSTRACT

Objective To construct a two-dimensional (2D) composite membrane and a three-dimensional (3D) biomimetic scaffold by silk fibroin (SF), type I collagen (Col-I) and hydroxyapatite (HA) blends in vitro, so as to study its physicochemical properties, as well as biocompatibility and explore the feasibility of its application in tissue engineering scaffold materials. Methods 2D composite membranes and 3D scaffolds were prepared by blending SF/Col-I/HA at the bottom of cell culture chamber and low temperature 3D printing combined with vacuum freeze drying. The biocompatibility was evaluated by mechanical property testing, scanning electron microscope and Micro-CT to examine the physicochemical properties of the material, and cell proliferation was detected to evaluate its biocompatibility. Results Stable 2D composite membrane and 3D porous structural scaffolds were obtained by blending and low temperature 3D printing. The mechanical properties were consistent. The pore size, water absorption, porosity and elastic modulus were all in accordance with the requirements of constructing tissue engineering bone. The scaffold was a grid-like white cube with good internal pore connectivity; HA was evenly distributed in the composite membrane, and the cells were attached to the composite membrane in a flat shape; the cells were distributed around pore walls of the scaffold. The shape of the shuttle was fusiform, and the growth and proliferation were good. Conclusions The composite membrane and 3D scaffold prepared by SF/Col-I/HA blending system had better pore connectivity and pore structure, which was beneficial to cell and tissue growth and nutrient transport. Its physicochemical properties and biocompatibility could meet the requirements of bone tissue engineering biomaterials.

9.
Journal of Medical Biomechanics ; (6): E434-E439, 2019.
Article in Chinese | WPRIM | ID: wpr-802375

ABSTRACT

As the main organ of the body, the load-bearing ability of bone is closely connected to its biomechanical properties. Bone is a complex hierarchical biomaterial, whose biomechanical properties are determined by its own structure and biological characteristics. Because of its mechanical adaptability, bone tissues represent different biomechanical properties under different mechanical loading. To quantify the complicated properties of bone and provide an accurate theoretical basis for clinical research, it is necessary to give insight into the biomechanical properties of bone at different levels and the constitutive relationships of bone tissues. In this review, relative researches on constitutive relationships in recent years were summarized based on its hierarchical biomechanical properties.

10.
Journal of Biomedical Engineering ; (6): 421-427, 2019.
Article in Chinese | WPRIM | ID: wpr-774189

ABSTRACT

In this study, we aim to investigat the effect of microgravity on osteoblast differentiation in osteoblast-like cells (MC3T3-E1). In addition, we explored the response mechanism of nuclear factor-kappa B (NF-κB) signaling pathway to "zero- " in MC3T3-E1 cells under the simulated microgravity conditions. MC3T3-E1 were cultured in conventional (CON) and simulated microgravity (SMG), respectively. Then, the expression of the related osteoblastic genes and the specific molecules in NF-κB signaling pathway were measured. The results showed that the mRNA and protein levels of alkaline phosphatase (ALP), osteocalcin (OCN) and type Ⅰ collagen (CoL-Ⅰ) were dramatically decreased under the simulated microgravity. Meanwhile, the NF-κB inhibitor α (IκB-α) protein level was decreased and the expressions of phosphorylation of IκB-α (p-IκB-α), p65 and phosphorylation of p65 (p-p65) were significantly up-regulated in SMG group. In addition, the IL-6 content in SMG group was increased compared to CON. These results indicated that simulated microgravity could activate the NF-κB pathway to regulate MC3T3-E1 cells differentiation.


Subject(s)
Animals , Mice , 3T3 Cells , Cell Differentiation , NF-kappa B , Physiology , Osteoblasts , Signal Transduction , Weightlessness Simulation
11.
Chinese Journal of Tissue Engineering Research ; (53): 1483-1488, 2019.
Article in Chinese | WPRIM | ID: wpr-743818

ABSTRACT

BACKGROUND: The silk fibroin/type II collagen composite scaffold has been prepared by low-temperature bio-3D printing technology in the previous study and the scaffold has good mechanical properties. Studies have shown that mechanical stimulation is beneficial to bone remodeling, and gradient loading strain is beneficial to the activation of osteoblasts and osteoclasts. OBJECTIVE: To co-culture silk fibroin/type II collagen composite scaffolds with chondrocytes under compression loading, to observe the proliferation of cells, and to observe the preliminary repair effect of silk fibroin/type II collagen composite scaffold on cartilage defects. METHODS: The silk fibroin/type II collagen composite scaffold was prepared by low-temperature 3D printing to detect the porosity of the scaffold. The passage 3 mouse chondrocytes ADTC-5 were inoculated on the silk fibroin/type II collagen composite scaffold and cultured under static culture and mechanical load respectively. (1) Static culture: blank scaffold was set as control, and cell proliferation was detected by MTT assay at 1, 3, 5, 7, 10, 14 days of inoculation. (2) Culture under mechanical load: blank scaffold was set as control. At 1 day after inoculation, 0%, 1%, 5%, 10%, 15%, 20% compressive strains were applied to the cell-scaffold complex, and continued to load for 3 days. Cell proliferation was detected by MTT assay, and the distribution, adhesion and morphology of the cells on the scaffold were observed by scanning electron microscopy and hematoxylin-eosin staining. A cartilage defect of 3.5 mm in diameter was made in the bilateral knee joint of New Zealand rabbits. The silk fibroin/type II collagen composite scaffold was implanted onto the left side, and no material was implanted onto the right side. The repair site was observed at 8 weeks after surgery. RESULTS AND CONCLUSION: (1) The porosity of the scaffold was (89.3±3.26)%, which was conducive to cell attachment. (2) After 5 days of static culture, the chondrocytes proliferated well on the surface of the composite scaffold. Under 0%, 1%, 5%, 10%, 15%, 20% compressive strains, the cell proliferation on the scaffold first increased and then decreased, wherein the cell proliferation was highest under 10% compressive strain, and lowest under 20% compressive strain. (4) Under the scanning electron microscopy, the chondrocytes in the 0% load group were distributed in the surface of the scaffold with irregularities, the cell morphology was obvious, and the cell protrusions were fully extended. There were few or no chondrocytes on the contact surface of the 10% load group, and more cells distributed on the lateral and internal surfaces of the first layer, but the cell morphology was flat with obvious protrusions. (5) Hematoxylin-eosin staining showed that the chondrocytes in the 0% load group were concentrated on the surface of the scaffold, and there were almost no cells in the pores, while the chondrocytes in the 10% load group were distributed in the scaffold pores. (6) There was still a circular defect model with no scaffold implantation, and no obvious repair appeared; similar hyaline cartilage appeared in the defect after scaffold implantation, but there was no adhesion to the surrounding defected cartilage, and the new hyaline cartilage was independent. Overall, the adsorption, proliferation and growth of chondrocytes on the silk fibroin-type II collagen scaffolds is better when the compressive strain is 10%, and the composite scaffold can be used as a repair material for cartilage defects.

12.
Clinical Medicine of China ; (12): 485-489, 2018.
Article in Chinese | WPRIM | ID: wpr-706714

ABSTRACT

Objective To investigate the effect of acupuncture combined with hyperbaric oxygen therapy on neurological function and daily living ability of patients with cerebral hemorrhage. Methods From January 2014 to June 2017,one hundred and twenty-three patients with cerebral hemorrhage which hospitalized in the Department of Neurosurgery of Hebei Provincial Corps Hospital were selected and randomly divided into three groups: acupuncture group, acupuncture + hyperbaric oxygen group ( combined group ) and control group. The acupuncture group was given acupuncture on the basis of routine medical treatment after minimally invasive surgery treatment; the combined group was treated with acupuncture treatment as well as hyperbaric oxygen therapy after minimally invasive surgery; the control group was only treated with conventional medical therapy without any special treatment. The scores of nerve function defect,Fusl-Meyer motor function assessment scale,daily living ability score,cognitive function score,Glasgow coma scale at the 40th day of admission were evaluated and compared respectively,and the clinical effect were evaluated as well. Results After treatment, the NHISS score of the control group,the acupuncture group and the combined group decreased in turn. The score of Fusl-Meyer exercise function rating scale, the daily living ability score, the cognitive function score and the Glasgow coma scale were increased in turn, and the differences were statistically significant ( F=276. 620, 76. 050,31. 770,116. 598,33. 745,P<0. 01) . The total effective rate of the control group,acupuncture group and combined group increased sequentially (61%,76%,90%),and the difference was statistically significant (χ2=18. 547,P<0. 01) . Conclusion Acupuncture therapy for patients with cerebral hemorrhage can effectively promote the improvement of nerve function, daily living ability and prognosis. Acupuncture combined with hyperbaric oxygen can get more obvious therapeutic effect.

13.
International Journal of Biomedical Engineering ; (6): 386-389,394, 2018.
Article in Chinese | WPRIM | ID: wpr-693142

ABSTRACT

Objective To investigate the effect and molecular mechanism of the combination of mechanical strain stimulation and icariin (ICA) on inhibiting the differentiation of osteoclasts induced by fatigue load stimulation. Methods The mouse mononuclear macrophage cell line RAW264.7 was cultured in vitro, and the blank control group was α-MEM complete medium. In the fatigue load group, RAW264.7 cells were treated with 5000 μεmechanical stretch strain, and then cultured in an osteoclast culture medium that was an α-MEM complete medium containing 40 ng/ml macrophage colony-stimulating factor and 40 ng/ml osteoclast differentiation factor. In the mechanical stimulation + ICA group, RAW264.7 cells were treated as the same procedure in the fatigue load group, and then cultured in an α-MEM complete medium containing 1 ×10 -5 mol/L ICA simultaneously with a 1000 μεtensile strain on the substrate. The activity of tartrate-resistant acid phosphatase (TRAP) was detected using a TRAP assay kit. The mRNA expression of the osteoclast marker genes, i.e. TRAP, cathepsin K(CTSK) and matrix metalloproteinase 9 (MMP-9) was detected by real-time RT-PCR. The nuclear translocation of nuclear factor kappa B (NF-κB) was analyzed by Western Blot. Results Compared with the fatigue load group, the combination of mechanical stimulation (1000 με substrate stretching) and ICA (1×10-5 mol/L) could significantly inhibit the activity of TRAP in osteoclasts (P<0.01) and reduce osteoclastosis. Moreover, that combination not only could down-regulate the mRNA expression of TRAP, CTSK and MMP-9 and the differences were statistically significant (all P<0.01), but also could inhibit the formation of osteoclasts by inhibiting the phosphorylation of P65, P50 and IκB-α in NF-κB signaling pathway. Conclusions The coupling of mechanical stimulation and ICA can effectively inhibit the osteoclast differentiation and the bone resorption induced by fatigue load, and the mechanism may involve regulating NF-κB signaling pathway.

14.
Journal of Medical Biomechanics ; (6): E285-E290, 2018.
Article in Chinese | WPRIM | ID: wpr-803802

ABSTRACT

MicroRNA (miRNA) is a kind of important gene expression regulatory molecules during biological process, but its regulation mechanism in metabolic process of bone tissues has not been completely clarified. In this review, the regulation of miRNA on osteoblast differentiation in microgravity environment was discussed. The positive and negative regulation of miRNA was summarized, respectively, with focus on introducing the mechanism of different genes. Some miRNA molecules that have important effects on bone metabolism under microgravity were enumerated. MiRNA plays an important role in regulating and controlling bone metabolic diseases in microgravity environment, and its related studies are significant for the prevention and treatment of bone loss induced by weightlessness.

15.
Journal of Medical Biomechanics ; (6): E572-E576, 2018.
Article in Chinese | WPRIM | ID: wpr-803754

ABSTRACT

Bone remodeling can keep the biomechanical properties, which is of great significance to maintain bone strength. Normal skeletal development requires tight coordination of transcriptional networks, signaling pathways and biomechanical cues, and many of these pathways are dysregulated in pathological conditions affecting bone. lncRNA is a group of RNAs with broad biogenesis, which are longer than 200 nt and highly conserved in their secondary and tertiary structures. Studies show that many lncRNAs are involved in normal development or balance of the skeletal system, the regulation of osteoblast differentiation, and the pathogenesis of osteosarcoma. Dysregulation of lncRNA expression is closely related to many bone diseases and it is expected to be a biomarker for predicting bone diseases. In this review, the characteristics and mechanisms of lncRNA involved in bone remodeling and its possible role were summarized, and the likely utility of IncRNAs as biomarkers and therapeutic targets for diseases of the skeletal system was discussed, including osteoarthritis, osteoporosis, and cancers of the skeletal system, so as to provide references for the better understanding and study on lncRNA biological function in organisms.

16.
Journal of Medical Biomechanics ; (6): E471-E476, 2018.
Article in Chinese | WPRIM | ID: wpr-803739

ABSTRACT

In the process of central nervous system (CNS) development and maturation, the biomechanical factors have not been highly valued for a long time. In recent years, a large number of studies have shown that mechanical environment strongly affects the migration, differentiation and maturation of nerve cells, as well as the cell-cell interactions. Mechanical factors play an important role in realization of the structure and function of the brain and spinal cord. This review briefly summarized the role of biomechanics in CNS perception, path-finding, regulation and network shaping during CNS development. The effects of static and dynamic mechanics on mechanobiological response of nerve cells were also introduced, hoping to provide some ideas for CNS reconstruction and repair in future.

17.
Chinese Medical Equipment Journal ; (6): 118-122,128, 2017.
Article in Chinese | WPRIM | ID: wpr-618956

ABSTRACT

Current research,application,advantages and disadvantages of wearable health monitoring items based on soft sensor technology in foreign countries and China were introduced and analyzed,and the application in diseases monitoring,emotion monitoring,monitoring of rehabilitation training,monitoring of sport training,operational safety monitoring in special environments,casualty search during war and disaster,monitoring of the elderly and children and etc were also described.The characteristics of the items were analyzed,and some countermeasures were put forward to solve the problems in materials safety,data quality,industrial standard,unclear efficacy and etc.The study and prospective of soft physiological sensing technology were expounded in detail.

18.
Journal of Medical Biomechanics ; (6): 122-129, 2017.
Article in Chinese | WPRIM | ID: wpr-614565

ABSTRACT

Objective To explore the effect of hypergravity on morphology and osteogenesis function of preosteoblast MC3T3-E1 ceils.Methods The cultured MC3T3-E1 cells under hypergravity by different loading forces were divided into five groups,including control group,5 g group,10 g group,15 g group and 20 g group.The experimental groups were loaded for 30 min each time in 3 successive days,and the control group with no g-value was synchronously exposed to the same surrounding.The morphology of cytoskeletal protein was observed by phalIoidin staining,The alkaline phosphatase (ALP) content was examined by ALP activity assay kit,the gene expression of ALP,collagen Ⅰ (Col Ⅰ),osteocalcin (OC),runt-related transcription factors (Runx2) was measured by real-time quantitative PCR,and the protein expression of Col Ⅰ and OC was tested by Western blotting.Results Under the condition of hypergravity,cell body of osteoblast became thinner,but its surface area increased significantly;with the structure of skeletal arrangement becoming loose,actin microfilament structure reduced so that the orderly arrangement of actin-like dispersion lowered.The gene expressions of related indicators of osteogenic differentiation including ALP,Col][,OC,Runx2 were significantly up-regulated,which was the same as Col Ⅰ protein and OC protein after hypergravity loading.A very minute quantity of small red-orange nodules was found in the control group,while the cells in experimental groups after hypergravity loading obviously formed various sizes of red-orange nodules.Conclusions Under hypergravity,changes in osteoblast morphology can be triggered by rearrangements of skeletal structure.Furthermore,osteoblast maturation and differentiation can be stimulated effectively by up-regulating differentiation-related gene and protein expressions.

19.
Journal of Medical Biomechanics ; (6): 83-87,102, 2017.
Article in Chinese | WPRIM | ID: wpr-606775

ABSTRACT

Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis,so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity.Metbods The microgravity environment in space was simulated by tail-suspension experiment,then the osteoporosis models of mice were built.A total of 32 C57BL/6J mice were randomly and evenly separated into four groups:normal group (normal),tail-suspension group (TS),physiological loading group (loading) and overloading group (overloading).Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test.After four weeks,tibial mechanical properties,micro-parameters of bone trabecular,biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed.Results A great loss of tibial cancellous bone,significantly lower tibial biomechanical expression,serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group.Physiological loading could clearly improve mechanical properties of bones,microstructure of bone trabecular,osteogenic activity and relative gene expression (P < 0.05).Overloading could also improve the condition of microgravity-induced osteoporosis,but the effect was not obvious (P > 0.05).Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model.Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis,while overloading can also counter microgravity-induced osteoporosis,but the results have no significant differences.

20.
Chinese Journal of Tissue Engineering Research ; (53): 7350-7355, 2015.
Article in Chinese | WPRIM | ID: wpr-484892

ABSTRACT

BACKGROUND:With the development of science and technology and modern aerospace, the effects of mechanobiology in extreme mechanical environment—high acceleration are becoming an issue of concern. Studies have shown that high acceleration has certain effects on the cels. OBJECTIVE:Based on a centrifuge, to design a cel loading centrifuge used for exploration of cel mechanobiology under high acceleration. METHODS:For the cel loading centrifuge, a culture plate or/and culture bottle ful of culture fluid was/were loaded with constant acceleration or variable velocity to explore the experimental feasibility. Besides, a finite element model was built by ANSYS software according to structure and properties of the rotor. The rotor system was calculated under equilibrium and dangerous working conditions, respectively, to analyze the stress and deformation distribution. Moreover, the strength of the main shaft was checked under the dangerous working conditions. Then the analysis results of ANSYS were compared with the results of strength check. RESULTS AND CONCLUSION:Experimental findings showed that the culture plate or/and the culture bottle could be used for (0-40)×g highly constant acceleration or variable acceleration loading. Through the simulation and comparison analysis, we confirmed the reliability of the cel loading centrifuge. This cel loading centrifuge can be used to implement the study of cel mechanobiology under high acceleration in the general biology laboratory. It also provides a basis for wide application of cel loading centrifuge in the future.

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