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OBJECTIVE: To review the relative researches about mechanical stimulation of stem cells differentiation in stem cells microenvironment in vitro. METHODS: The recent related literature about stem cells differentiation in vitro was reviewed and summarized. RESULTS: The mechanical loads (including shear stress, mechanical strain, and stress), substrates stiffness, substrates nanotopography, and cell shape were the 4 important aspects of mechanical factors regulating stem cells differentiation. The mechanical stimulation can simulate the in vivo microenvironment, which can alter the size, shape, alignment, and differentiation state of stem cells, can change the expression of their differentiation markers, and can affect the lineage commitment of stem cells. CONCLUSION: Mechanical stimulation play an important role in regulating stem cells differentiation and cells morphology in addition to chemical and biological factors.
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Diferenciación Celular/fisiología , Microambiente Celular , Nanoestructuras , Células Madre/citología , Células Madre/fisiología , Estrés Mecánico , Animales , Fenómenos Biomecánicos , Técnicas de Cultivo de Célula , Forma de la Célula , Células Cultivadas , Células Madre Embrionarias/fisiología , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Humanos , Mecanotransducción Celular/fisiología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/fisiología , Propiedades de Superficie , Ingeniería de Tejidos/métodosRESUMEN
OBJECTIVE: To review the research application and advance of synovium-derived mesenchymal stem cells (SMSCs) in tissue engineering. METHODS: The recent related literature was reviewed, concerning isolation method, characteristics of SMSCs, and its application in tissue engineering. RESULTS: SMSCs are multipotent cell population with characteristics of easy isolation and high proliferation, which have been applicated in the cartilage, tendon, ligament, and bone tissue engineering. CONCLUSION: SMSCs is a new member of mesenchymal stem cells family. It appears to be promising seed cells for tissue engineering, but further research is needed.
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Células Madre Mesenquimatosas/citología , Membrana Sinovial/citología , Ingeniería de Tejidos/métodos , Diferenciación Celular , Células Cultivadas , HumanosRESUMEN
We aimed to develop a hybrid scaffold with a porous structure and similar composition as natural bone for the controlled release of bone morphogenetic protein-2 (BMP-2) to enhance bone regeneration. We fabricated a gelatin/nanohydroxypatite (nHAP) scaffold by glutaraldehyde chemical cross-linking a gelatin aqueous solution with nHAP granules at a 5:1 ratio (v/w). Then, fibrin glue (FG) mixed with recombinant human BMP-2 (rhBMP-2) was infused into the gelatin/nHAP scaffold and lyophilized to develop an rhBMP-2-loaded gelatin/nHAP/FG scaffold. On scanning electron microscopy, the composite had a 3-D porous structure. The rhBMP-2 release kinetics from the hybrid scaffold was sustained and slow, and release of rhBMP-2 was complete at 40 days. Immunohistochemistry, azo-coupling and alizarin S-red staining were used to study in vitro differentiation of human bone-marrow mesenchymal cells (hBMSCs). Strong positive staining results confirmed that rhBMP-2 released from the scaffold could improve osteocalcin (OCN) and alkaline phosphatase (ALP) expression and calcium deposition formation. RT-PCR results showed significantly high mRNA expression of ALP and OCN in hBM-MSCs cultured on the gelatin/nHAP/FG scaffold with rhBMP-2. DNA assay demonstrated that the scaffold was noncytotoxic and could promote hBMSC proliferation from the components of the hybrid scaffold, not released rhBMP-2. The hybrid scaffolds were then used to repair critical-size segmental bone defects of rabbit radius. Gross specimen, X-ray, bone histomorphology and bone mineral density assay demonstrated that the rhBMP-2-loaded gelatin/nHAP/FG scaffold had good osteogenic capability and could repair the segmental bone defect completely in 12 weeks.
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Proteínas Morfogenéticas Óseas/química , Proteínas Morfogenéticas Óseas/farmacología , Regeneración Ósea/fisiología , Durapatita/química , Fibrina/química , Gelatina/química , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacología , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Factor de Crecimiento Transformador beta/química , Factor de Crecimiento Transformador beta/farmacología , Animales , Proteína Morfogenética Ósea 2 , Proteínas Morfogenéticas Óseas/genética , Femenino , Humanos , Cinética , Masculino , Microscopía Electrónica de Rastreo , Conejos , Proteínas Recombinantes/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Crecimiento Transformador beta/genéticaRESUMEN
OBJECTIVE: To investigate the clinical applicability and value of internal fixator for the reconstruction of lumbar isthmus in the treatment of lumbar vertebral spondylolysis and to lay a foundation for its clinical application. METHODS: Six teen healthy goats weighing 22.65-31.22 kg were selected to establish the models of vertebral spondylolysis at L5, which thereafter were randomized into two groups (n=8): bone graft group in which 0.8-1.1 g fresh autogenous bone was transplanted into the isthmus spondylolysis area, and internal fixation with bone graft group in which internal fixator was installed before transplanting 0.8-1.1 g fresh autogenous bone into the isthmus spondylolysis area. All animals were killed 8 weeks after operation to receive imaging, topographic anatomy and histology detection. Meanwhile, biomechanics test was performed by using 5 donated vertebral body specimens (4 males and 1 female aged 35-51 years old). The left isthmus of Ls vertebra was transected to serve as lumbar vertebral spondylolysis model. A mini-displacement sensor was put at the transected ends of the isthmus. Then loading was conducted with a constant velocity of 2 mm/min by electronic omnipotent tester simulating the direction of fixation force of the internal fixator, and the deformation value of the transected ends was collected by a dynamic data collector and analyzer. The loading was continued until the vertebra specimens were damaged. The deformation of displacement sensor and the closure of transected ends of the lumbar isthmus were observed. RESULTS: All the goats behaved normally shortly after operation, and no nerve injury induced by operation and no wound infection occurred. Bilaterally oblique X-ray films of lumbar vertebra and topographic anatomy 8 weeks after operation showed the fusion rate of the internal fixation and bone graft group and the bone graft group was 100% and 62.5%, respectively, indicating there was a significant difference (P < 0.05). Histology observation showed 3 goats in the bone graft group presented empty bone trabecula, empty bone lacuna and the disappearance of osteocytes at the transected ends of lumbar isthmus; while in the internal fixation and bone graft group, the bone trabecula grew into cancellous structures with hematopoietic and fatty bone marrow tissue inside, and parts of the bone trabecula had various degrees of mosaic-like pattern. During the upload, the biomechanics test and data processing results showed when the external load was 40 N, the deformation of displacement sensor was identified and the gap between the transected ends of lumbar isthmus started to close; then with the increase of external load, the displacement sensor tended to ascend in a linearity manner; while when the external load was 212 N, the displacement sensor had no further deformation, the gap between the transected ends of lumbar isthmus was completely closed, and the pressor effect appeared. CONCLUSION: The internal fixator for the reconstruction of lumbar isthmus has mechanical effects of stabilizing and elevating pressure with a high fusion rate.
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Fracturas no Consolidadas/cirugía , Fijadores Internos , Vértebras Lumbares/cirugía , Fracturas de la Columna Vertebral/cirugía , Animales , Femenino , Fijación Interna de Fracturas/instrumentación , Cabras , Masculino , Diseño de PrótesisRESUMEN
OBJECTIVE: To investigate the effects of the decoction of Rhizoma Dioscoreae septemlobae (RD) on the biomechanical and bone histomorphometric parameters of femur in the ovariectomized rats. METHODS: 25 female Wistar rats without pregnancy and deliver were divided into 5 groups randomly: sham (sham-operation), ovariectomy (OVX), OVX + high dosage RD (4 g/kg x d), OVX + middle dosage RD (2 g/kg x d) and OVX + low dosage RD (1 g/kg x d), n = 5 in every group. After intragastric administration 12-week period continuously, the biomechanical and the bone histomorphometric parameters of the femur of the rats in every group were determined, respectively, including percentage of trabecular bone volume (TBV%), percentage of trabecular osteoid (TOS%), mean osteoid width (MOSW), percentage of mineralizing surface (MdS%), percentage of double mineralizing surface (DMds%), percentage of DMds/MdS (%), percentage of travecular formation surface (TFS%), percentage of trabecular resorption surface (TRS%), mineral apposition rate (MAR), mineralizing lag time (MLT). RESULTS: The maximum loading, deflection, the maximum strain of the femur in the OVX group was 125.78 +/- 15.48 (N), 1.87 +/- 0.22 (mm), 9.34 +/- 1.10 (%), it was significantly lower than that in the sham group ( P< 0.05, P < 0.01), respectively. The maximum loading and maximum stress was increased in different extent in the every dose group of OVX + RD, respectively. TBV% of femur was significantily lower in the OVX group than that in the sham group (P < 0.01). The MdS%, DMds%, DMds/MdS (%), TOS%, MOSW, TRS%, MAR was significantly higher in the OVX group than that in the sham group, respectively (P < 0.01). In the RA high and middle dosage group, the TBV% of femur was significantly higher than that in the model group (P < 0.05), and the MdS%, DMds%, DMds/MdS (%), TRS%, TOS%, MOSW, MAR was significantly lower than that in the model group, respectively (P < 0.05), and MLT was decurtated slightly (P > 0.05). CONCLUSION: The decoction of RD can decline the bone turnover and the loss of bone of femur in the ovariectomized rats.
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Dioscorea/química , Medicamentos Herbarios Chinos/farmacología , Fémur/efectos de los fármacos , Ovariectomía , Animales , Densidad Ósea/efectos de los fármacos , Remodelación Ósea/efectos de los fármacos , Resorción Ósea/prevención & control , Medicamentos Herbarios Chinos/administración & dosificación , Femenino , Fémur/anatomía & histología , Fémur/fisiología , Osteoporosis/prevención & control , Plantas Medicinales/química , Distribución Aleatoria , Ratas , Ratas Wistar , Soporte de PesoRESUMEN
OBJECTIVE: To investigate the effects of the decoction of Rhizoma Dioscorea septemlobae (RD) on the bone metabolism in ovariectomized rats. METHOD: Thirty female, 3-month-old Wistar rats without pregnancy and deliver were randomly divided into 6 groups: sham (sham-operation), ovariectomy (OVX), OVX + diethylstilbestrol, OVX + high dose RD (4 g x kg(-1) x d(-1)), OVX + middle dose RD (2 g x kg(-1) x d(-1)) and OVX + low dose RD (1 g x kg(-1) x d(-1)) (n = 5 in every group). After 12-week period of continuous treatment, the urinary samples and blood samples were collected for the determination of serum estrodiol (E2), calcium (Ca), phosphorus (P), bone glaprotein (BGP), alkaline phosphatase (ALP), urinary calcium/creatinine (Ca/Cr), phosphorus/ creatinine (P/Cr) and deoxypyridioline/creatinine (DPD/Cr). The uteri were removed and weighed. The bone mineral density (BMD) and the biomechanical parameters of the femur of the rats in every group were determined, respectively. RESULT: The coefficient of uteri in every dose group of OVX + RD was significantly higher than that in the OVX group (P < 0.01). The concentration of serum ALP, BGP and urinary DPD/Cr, Ca/Cr in the OVX group was significantly higher than that in the sham group (P < 0.05), respectively, However, that in the every dose of OVX + RD was lower than that in the OVX group, respectively. There was no significan difference in the concentration of serum Ca, P and urinary P/Cr in every group, respectively. The bone mineral density (BMD) in the OVX group was (0.032 +/- 0.007) g x cm(-2) and was significantly lower than that in the sham group (P < 0.01). However, the value in the group of every dose OVX + RD was significantly higher than that in the OVX group (P < 0.05, P < 0.01), respectively. The maximum loading, deflection and the maximum strain of the femur in the OVX group were (125.78 +/- 15.48) N, (1.87 +/- 0.22) mm, (9.34 +/- 1.10) % and were significantly lower than those in the sham group (P < 0.05, P < 0.01), respectively. The maximum loading and maximum stress were increased in different extent in the every dose group of OVX + RD, respectively. CONCLUSION: The decoction of RD can inhibit bone absorption, decline bone turnover and improve the loss of bone in ovariectomized rats.