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BACKGROUND:Previous studies have shown that home-made porous tantalum has non-toxicity and good biocompatibility, and can promote osteogenesis. Herein, we explore the mechanisms of tantalum-bone interface osseointegration.OBJECTIVE:To observe the morphological characteristics and expressions of integrin β1 and fibronectin on the interface between porous tantalum and bone tissues after implantation into the right rabbit femur, and to evaluate the biological mechanisms of tantalum-bone interface osseointegration.METHODS: Animal models of bilateral femoral condyle defects were made in Japanese big ear rabbits. Porous tantalum rod and allogeneic bone were respectively implanted into the left (experimental group) and right (control group) femur of rabbits. The animal specimens at the bone defect region were taken and made into paraffin sections and hard tissue sections at postoperative 2, 4, 8 weeks for morphological observation of new bone at the junction between the tantalum rod and host bone under light microscope, for osteogenic observation of the tantalum-bone interface under scanning electron microscope, and for immunohistochemical detection of integrin β1 and fibronectin expression.RESULTS AND CONCLUSION:Porous tantalum was bonded closely with the host bone. The loose and thick fibrous capsule was observed in the early stage and became thinner in the late stage shown by hematoxylin-eosin staining. The new bone was visible on tantalum-bone interface. Hard tissue slicing observation showed that the new bone was seen on the porous tantalum-bone interface, blood capillaries grew into the pores at postoperative 2 weeks and the pores were full of new bone tissues at postoperative 4 and 8 weeks. Under the scanning electron microscope, the osteoblasts appeared on the tantalum surface and in the pores at the early stage, and bone maturation and lamelar bone were seen at the late stage. The immunohistochemical results showed that the expression of integrin β1 in the experimental group was significantly lower than that in the control group at postoperative 2 weeks (P 0.05). In addition, there was a decline trend in the expression of integrin β1 and fibronectin atpostoperative 2, 4, 8 weeks. To conclude, the porous tantalum material is beneficial to enhance adhesion of osteoblasts on the surface and inside the micro-pores. Increased expression of integrin β1 and fibronectin on the tantalum-bone interface at early stage may promote early osteogenesis, while their decreased expression at bone maturing stage can promote osseointegration and bone remodeling.
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BACKGROUND: Previous studies have demonstrated that the Chinese porous tantalum made in China has non-toxicity and good biocompatibility, which can promote osteogenesis. OBJECTIVE: To investigate the effects of transforming growth factor β1 on proliferation, cel cycle and secretion of osteoblasts on porous tantalum/MG63 osteoblast-like cel composites. METHODS: Passage 3 MG63 osteoblast-like cel suspension (1×109/L) was seeded onto the porous tantalum, then the cel composites were inoculated in the medium with 0, 0.5, 5 and 10 μg/L transforming growth factor β1, respectively. The proliferation of osteoblasts was detected by cel counting kit-8 assay at 1-13 days after inoculation; the cel morphology and ultrastructure observed by scanning electron microscope and transmission electron microscopy; and level of col agen type I detected by enzyme-linked immunosorbent assay. RESULTS AND CONCLUSON: 0.5, 5, 10 μg/L transforming growth factor β1 could promote the osteoblast proliferation, and cel proliferation in the 5 μg/L transforming growth factor β1 group was higher than that in the other groups; in the 5 μg/L transforming growth factor β1 group, laminated osteoblasts adhered on the surface and grew into inner of porous tantalum, which extended more pseudopodia toward the scaffold; osteoblasts-secreted matrix could cover the scaffold and numerous rough endoplasmic reticulum, free ribosomes, dense mitochondria, Golgi apparatus as wel as matrix vesicles could be found in the cytoplasm. In addition, the level of col agen type I in the 5 μg/L transforming growth factor β1 group was significantly higher than that in the other groups (P < 0.05). These results indicate that transforming growth factor β1 can promote proliferation, and col agen type I secretion of osteoblasts on porous tantalum/MG63 osteoblast-like cel composites, and the optimum mass concentration of transforming growth factor β1 is 5 μg/L.
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Objective:To study the influence of bone morphogenetic protein-7 ( BMP-7 ) on chondro-cyte secretion and expression of type Ⅱ collagen ( Col-Ⅱ) , aggrecan ( AGG ) and SRY-related high mobility group-box gene 9 ( Sox9 ) mRNA in porous tantalum-chondrocyte composites.Methods: The articular chondrocytes were isolated from 3-week-old New Zealand immature rabbits and identified.The 2nd generation of chondrocytes with 1 ×106/mL inoculate concentration was seeded in porous tantalum and divided into 4 groups, and control group ( tantalum/chondrocyte) , 50μg/L BMP-7 group (50μg/L BMP-7/tantalum/chondrocyte) , 100 μg/L BMP-7 group ( 100 μg/L BMP-7/tantalum/chondrocyte ) , and 200 μg/L BMP-7 group ( 200 μg/L BMP-7/tantalum/chondrocyte ) .The proliferation of chondro-cytes was measured by CCK-8 assay.The chondrocyte growth and morphology were observed by scanning electron microscopy ( SEM) .The synthesis of glycosaminoglycan ( GAG) in chondrocytes was tested by dimethyl methylene blue ( DMMB) colorimetric quantification method.Col-Ⅱ, AGG and Sox9 mRNA in chondrocytes were detected by real-time PCR.Results: The chondrocytes were spindle-shaped in 24 hours of primary cell culture and most cells became polygonal shaped in 4 days.The chondrocytes were affirmed by alcian blue, safranin O and Col-Ⅱimmunocytochemistry staining.The result of CCK-8 assay showed that the level of cell proliferation in 100 μg/L BMP-7 groups were higher than those in the other groups ( P<0 .05 ) .The chondrocytes implanted into porous tantalum scaffolds with BMP-7 had better functions, by which cytoplasmic processes developed and extended to the surface and inner of porous tan-talum by SEM observation.DMMB quantitative determination of GAG showed that GAG amount of chon-drocytes in 100 μg/L BMP-7 groups was significantly higher than those in the other groups ( P<0 .05 ) . The expressions of Col-Ⅱ, AGG and Sox9 mRNA in chondrocytes were up-regulated in the experimental groups, compared with the control group and the best effect appeared when concentration of BMP-7 was 200μg/L.(P<0.05).Conclusion:BMP-7/tantalum/chondrocytes composites enhanced in vitro chon-drocyte proliferation and extracellular matrix greatly, and can promote chondrogenic gene expression.
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Objective To investigate cytotoxicity,biocompatibility and new bone formation traced of Chinese porous tantalum,and provide experimental strategies for further clinical application.Methods The physical properties of the porous tantalum were observed by the SEM.The osteoblasts were isolated from rabbit embryo.The extract fluid from tantalum was made.The cytotoxicity and proliferation of osteoblasts compounded with porous tantalum in vitro were detected by the MTT assay.The osteoblasts were co-cultured with extract of tantalum in vitro and the morphological changes,proliferation and adhesion were observed under SEM.A total of 24 New Zealand rabbits were used to establish the model of femoral condyles with porous tantalum bars implanted.Among which 4 of them was injected with calcein and alizarin on the 5th day and the 19th day and sacrificed at 10 week postoperatively.The specimens were observed with LSCM at 488 nm and 543 nm wavelength respectively.The remained 20 animals were sacrificed successively at 2,4,8,12 weeks of implantation,then were examined by histological observation.Results The SEM showed that the pore of porous tantalum were three-dimensional connected morphology.MTT assay showed that the osteoblasts grew well in extract and no significant difference between experimental and control groups.The osteoblasts grew and spread extensively on porous tantalum.Early on co-culture,the osteoblasts attached to the surface and inner walls of material,in the later stage,the osteoblasts excreted bone matrix over the surface of porous tantalum.The animal model showed that porous tantalum was bonded closely with host bone.Hard slicing showed that new bone and capillary regenerated on tantalum-bone interface at 2,4 weeks postoperatively.The pores were full with bone tissue at 8,12 weeks.The LSCM indicated that the green and red fluorescence-labeled new bone was displayed on tantalum-bone interface,while the red zone located around the green zones.They appeared to be discontinuous at early stage,but connected with each other at the end.Conclusion The Chinese porous tantalum has good biocompatibility and no cytotoxicity.The contact osteogenesis and bone conduction exist in tantalum-bone interface,and in a time-dependent manner.
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OBJECTIVE:To investigate the variation degrees of the active components in the same batch No.GuanxinⅡdecoctions under the same decoction technics.METHODS:Crude drug of the same batch No.of the same formula was decocted,every decoction detail was tried to be kept under control,the contents of the active components in 5 batches of GuanxinⅡdecoctions were determined and the mean value of which was calculated as well.RESULTS:In terms of the contents of crude drugs,those of tanshinol,protocatechualdehyde,peoniflorin and ferulic acid were respectively(0.773?0.0 656)mg/g,(36.591?3.0 590)?g/g,(2.655?0.2 454)mg/g,(85.052?7.5 469)?g/g.CONCLUSION:Referenced by the criterion that the content variation coefficient among different batches of decoctions should be less than 10%,the contents of active components in each decoction were all up to the standards.Referenced by the criterion that there should be no statistical difference among different batches of decoctions,more influential factors on the active components of decoctions should be brought into consideration in the quality control.
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Objective To study the pharmacokinetics of ferulic acid (FA) in plasma of the healthy female volunteers after oral administration of Shenghua decoction.Methods Using p-hydroxybenzaldehyde as the internal standard, the plasma concentration of FA was determined by RP-HPLC. Plasma samples were extracted and treated with boiling water and 3P97 programme was used to calculate the pharmacokinetic parameters. Results The main pharmacokinetic parameters of FA were as follows: T1/2?=18.72 min ,T1/2?=79.21 min,T1/2 Ka=11.19 min,AUC=18004.87 ?g?min?L-1,CL=0.17L?min-1?kg-1,Cmax=206.30 ?g?L-1, Tpeak=22.78 min.Conclusion After oral administration of Shenghua decoction, FA could be absorbed and eliminated rapidly and pharmacokinetics of FA conforms to a two-compartment open model.
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OBJECTIVE: To investigate the concentration- time curve of ferulic acid(FA) in serum of healthy male volunteers after oral administration of Guanxin II (GXEH) and to study its pharmacokinetic parameters.METHODS: Serum FA level was determined by HPLC in healthy male volunteers after single oral administration of GXEH(4.5g?kg-1) decoction. RESULTS: No double - peak occurred in the concentration - time curve of FA.6 -fold interindividual variation was noted in maximum blood drug level.The pharmacokinetic parameters were stated as follows: Ka: (0.26?0.350) min-1; Ke: (0.013?0.004 17)min-1;t1/2Ke: (63.45?32.288)min;tmax:(24.117?14.631) min, AUC:(13 263.51?6 478.275)ng?min-1?mL-1; CL/F(s):(0.000 44?0.000 268)L?g-1?min-1.CONCLUSION:There is a significant individual FA level difference in healthy male volunteers after oral oral administration of GXEH decoction,and both the absorption and the elemination of FA are fast.
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OBJECTIVE:To study the presence of the chemical compositions of Guan XinⅡ(GXEH)oral decoction in human serum.METHODS:The analysis of finger prints of the medicated serum sample obtained from the volunteers treated with GXEH decoction was conducted with3different pretreatment procedures and2different HPLC methods,and which were compared with decoction.RESULTS:The numbers of the discrepant chromatographic peaks detected from the decoction and the medicated serum were respectively less than30and10,danshensu,protocatechuic aldehyde,ligustrazine,paeoniflorin were failed to be traced in the latter.CONCLUSION:The numbers of chemical compositions of the compound preparation that can be traced in serum were limited and the active components that entered into body may be relatively limited in numbers.After oral administration of compound preparation,a part of chemical compositions of which may not presented as its original form in serum.
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OBJECTIVE:To provide practical standard for sampling the crude drugs.METHODS:To look up and analyse the relevent literature to the subject.RESULTS:The condition of sampling the cruds drugs for research reflected by literature is confused without standard given.CONCLUSION:It is a practical way to pay attention to the growing area,the channel to be obtained and authentication and analysis of crude drugs in research to control the quality.