目的探讨固骼生(45S5)对体外培养鼠鼻中隔软骨细胞增殖及向成骨细胞分化的促进作用。方法利用体外细胞培养技术建立孕21 d SD大鼠鼻中隔软骨细胞培养体系,根据培养基的不同分为实验组(培养基中放入45S51mg/ml)和空白对照组。在倒置相差...目的探讨固骼生(45S5)对体外培养鼠鼻中隔软骨细胞增殖及向成骨细胞分化的促进作用。方法利用体外细胞培养技术建立孕21 d SD大鼠鼻中隔软骨细胞培养体系,根据培养基的不同分为实验组(培养基中放入45S51mg/ml)和空白对照组。在倒置相差显微镜下观察细胞生长状态;采用MTT染色法检测软骨细胞增殖变化;第8、12、15、18d取材分光比色检测碱性磷酸酶(ALP);第13d透射电镜下观察45S5周围软骨细胞基质的钙化等成骨指标变化。结果实验组软骨细胞增殖明显高于对照组;第12、15d ALP的分泌明显高于对照组,差异均有统计学意义(均P<0.05);第13d透射电镜下可观察测45S5周围软骨细胞基质的钙化结节致密电子层。结论45S5可促进体外培养鼠鼻中隔软骨细胞增殖及向成骨细胞分化。展开更多
Mechanical alloying and annealing at 1150 °C for 2 h under an argon atmosphere were used to prepare Ti-45S5 bioglass nanocomposites. Ti-45S5 bioglass material was chemically modified by silver. The antibacterial ...Mechanical alloying and annealing at 1150 °C for 2 h under an argon atmosphere were used to prepare Ti-45S5 bioglass nanocomposites. Ti-45S5 bioglass material was chemically modified by silver. The antibacterial activity of Ti-10% 45S5 bioglass nanocomposite containing silver against Streptococcus mutans and Staphylococcus aureus was studied. Nanocomposites were characterized by X-ray diffraction, scanning electron microscopy equipped with an electron energy dispersive spectrometer and transmission electron microscopy to evaluate phase composition, crystal structure and grain size. In vitro bacterial adhesion study indicated a significantly reduced number of Streptococcus mutans and Staphylococcus aureus on the bulk nanostructured Ti-45S5 bioglass-Ag plate surface in comparison to that on microcrystalline Ti plate surface. Nanostructured Ti-based biomaterials can be considered to be the future generation of dental implants.展开更多
The key research and development steps for bioactive glass (45S5 Bioglass) are documented from the date of discovery in 1969 through FDA approvals of the first dental, ENT, maxillo-facial and orthopedic clinical produ...The key research and development steps for bioactive glass (45S5 Bioglass) are documented from the date of discovery in 1969 through FDA approvals of the first dental, ENT, maxillo-facial and orthopedic clinical products. Understanding the mechanisms and quantifying the rapid surface reactions to form a bone-bonding hydroxyl-carbonate apatite (HCA) layer on the bioactive glass in contact with living bone was a vital part of the early development of this class of biomaterials. A key later discovery was enhanced osteogenesis and in situ bone regeneration by controlled release of ionic dissolution products from the bioactive glass particulates that leads to up-regulation and activation of seven families of genes, a process called osteostimulation.展开更多
A new kind of biomedical Ti-45S5 Bioglass-Ag nanocomposites and their scaffolds with antibacterial function was developed by the introduction of 1.5 wt% Ag into the Ti-10 wt% 45S5 Bioglass matrix. The microstructure, ...A new kind of biomedical Ti-45S5 Bioglass-Ag nanocomposites and their scaffolds with antibacterial function was developed by the introduction of 1.5 wt% Ag into the Ti-10 wt% 45S5 Bioglass matrix. The microstructure, hardness and corrosion resistance in Ringer solution of the Ag-doped Ti-45S5 glass were investigated. The Vickers hardness of the bulk Ti-10 wt% 45S5 Bioglass-1.5 wt% Ag nanocomposites reached 480 HVo.3. Contact angles of water on the micro- crystalline Ti and nanostructured Ti-10 wt% 45S5 Bioglass-1.5 wt% Ag sample were determined and show visible decrease from 55.2° to 49.6°. In vitro tests culture of normal human osteoblast cells showed very good cells proliferation, colonization and multilayering. In vitro bacterial adhesion study indicated a significantly reduced number of bacteria （Staphylococcus aureus） on the bulk nanostructured Ti-10 wt% 45S5 Bioglass-1.5 wt% Ag plate surface in comparison with that on microcrystalline Ti plate surface. Development of porous Ti-10 wt% 45S5 Bioglass-1.5 wt% Ag scaffolds aims in enhancing bone ingrowth and prosthesis fixation.展开更多
Bioactive glasses(BGs)are promising bone substitute materials.However,under certain circumstances BGs such as the well-known 45S5 Bioglass®(composition in wt%:45.0 SiO2,24.5 Na2O,24.5 CaO,6.0 P2O5)act cytotoxic d...Bioactive glasses(BGs)are promising bone substitute materials.However,under certain circumstances BGs such as the well-known 45S5 Bioglass®(composition in wt%:45.0 SiO2,24.5 Na2O,24.5 CaO,6.0 P2O5)act cytotoxic due to a strong increase in pH caused by a burst release of sodium ions.A potential alternative is a sodiumreduced fluoride-containing BG belonging to the CaO–MgO–SiO2 system,namely BG1d-BG(composition in wt%:46.1 SiO2,28.7 CaO,8.8 MgO,6.2 P2O5,5.7 CaF2,4.5 Na2O),that has already been evaluated in-vitro,in-vivo and in preliminary clinical trials.Before further application,however,BG1d-BG should be compared to the benchmark amongst BGs,the 45S5 Bioglass®composition,to classify its effect on cell viability,proliferation and osteogenic differentiation of human mesenchymal stem cells(MSCs).Therefore,in this study,the biocompatibility and osteogenic potential of both BGs were investigated in an indirect and direct culture setting to assess the effect of the ionic dissolution products and the BGs’physical presence on the cells.The results indicated an advantage of BG1d-BG over 45S5 Bioglass®regarding cell viability and proliferation.Both BGs induced an earlier onset of osteogenic differentiation and accelerated the expression of late osteoblast marker genes compared to the control group.In conclusion,BG1d-BG is an attractive candidate for further experimental investigation.The basic mechanisms behind the different impact on cell behavior should be assessed in further detail,e.g.by further alteration of the BG compositions.展开更多
Carbon nanotube reinforced bioglass composites have been successfully synthesized by two comparative sintering techniques, i.e., spark plasma sintering （SPS） and conventional compaction and sinteirng. The composites...Carbon nanotube reinforced bioglass composites have been successfully synthesized by two comparative sintering techniques, i.e., spark plasma sintering （SPS） and conventional compaction and sinteirng. The composites show improved mechanical properties, with SPS technique substantially better than conventional compact and sintering approach. Using SPS, compared with the 45S5Bioglass matrix, the maximum flexural strength and fracture toughness increased by 159% and 105%, respectively. Enhanced strength and toughness are attributed to the interfacial bonding and bridging effects between the carbon nanotubes and bioglass powders during crack propagations.展开更多
As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based...As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based on the supposition that the capacity degradation of the binary Mg50Ni50 alloy and ternary Mg45Cu5Ni50 alloy electrodes is solely due to the corrosion of Mg, the active hydrogen storage element. That means amount of capacity degradation is determined by the corrosion current time, which is also the time of operation. The corrosion current J corr dependence on cycling time was deduced. A mathematic relation between the cycling capacity retention C N / C 1 (%) and the duration of operation was also deduced. The data calculated from the equations deduced agree well with those of the experiment result. The loss of the active hydrogen absorbing element Mg is proved to be the main cause for cycling capacity deterioration in the present investigation.展开更多
文摘目的探讨固骼生(45S5)对体外培养鼠鼻中隔软骨细胞增殖及向成骨细胞分化的促进作用。方法利用体外细胞培养技术建立孕21 d SD大鼠鼻中隔软骨细胞培养体系,根据培养基的不同分为实验组(培养基中放入45S51mg/ml)和空白对照组。在倒置相差显微镜下观察细胞生长状态;采用MTT染色法检测软骨细胞增殖变化;第8、12、15、18d取材分光比色检测碱性磷酸酶(ALP);第13d透射电镜下观察45S5周围软骨细胞基质的钙化等成骨指标变化。结果实验组软骨细胞增殖明显高于对照组;第12、15d ALP的分泌明显高于对照组,差异均有统计学意义(均P<0.05);第13d透射电镜下可观察测45S5周围软骨细胞基质的钙化结节致密电子层。结论45S5可促进体外培养鼠鼻中隔软骨细胞增殖及向成骨细胞分化。
文摘Mechanical alloying and annealing at 1150 °C for 2 h under an argon atmosphere were used to prepare Ti-45S5 bioglass nanocomposites. Ti-45S5 bioglass material was chemically modified by silver. The antibacterial activity of Ti-10% 45S5 bioglass nanocomposite containing silver against Streptococcus mutans and Staphylococcus aureus was studied. Nanocomposites were characterized by X-ray diffraction, scanning electron microscopy equipped with an electron energy dispersive spectrometer and transmission electron microscopy to evaluate phase composition, crystal structure and grain size. In vitro bacterial adhesion study indicated a significantly reduced number of Streptococcus mutans and Staphylococcus aureus on the bulk nanostructured Ti-45S5 bioglass-Ag plate surface in comparison to that on microcrystalline Ti plate surface. Nanostructured Ti-based biomaterials can be considered to be the future generation of dental implants.
文摘The key research and development steps for bioactive glass (45S5 Bioglass) are documented from the date of discovery in 1969 through FDA approvals of the first dental, ENT, maxillo-facial and orthopedic clinical products. Understanding the mechanisms and quantifying the rapid surface reactions to form a bone-bonding hydroxyl-carbonate apatite (HCA) layer on the bioactive glass in contact with living bone was a vital part of the early development of this class of biomaterials. A key later discovery was enhanced osteogenesis and in situ bone regeneration by controlled release of ionic dissolution products from the bioactive glass particulates that leads to up-regulation and activation of seven families of genes, a process called osteostimulation.
文摘A new kind of biomedical Ti-45S5 Bioglass-Ag nanocomposites and their scaffolds with antibacterial function was developed by the introduction of 1.5 wt% Ag into the Ti-10 wt% 45S5 Bioglass matrix. The microstructure, hardness and corrosion resistance in Ringer solution of the Ag-doped Ti-45S5 glass were investigated. The Vickers hardness of the bulk Ti-10 wt% 45S5 Bioglass-1.5 wt% Ag nanocomposites reached 480 HVo.3. Contact angles of water on the micro- crystalline Ti and nanostructured Ti-10 wt% 45S5 Bioglass-1.5 wt% Ag sample were determined and show visible decrease from 55.2° to 49.6°. In vitro tests culture of normal human osteoblast cells showed very good cells proliferation, colonization and multilayering. In vitro bacterial adhesion study indicated a significantly reduced number of bacteria （Staphylococcus aureus） on the bulk nanostructured Ti-10 wt% 45S5 Bioglass-1.5 wt% Ag plate surface in comparison with that on microcrystalline Ti plate surface. Development of porous Ti-10 wt% 45S5 Bioglass-1.5 wt% Ag scaffolds aims in enhancing bone ingrowth and prosthesis fixation.
基金We thank Dr.Jorg Fellenberg for technical support and inspiring scientific discussion and Sebastian Wilkesmann and Frederike Hohenbild for their support in designing the figuresThis study was funded by the research fund of the Heidelberg Orthopedic University Hospital.Dr.Fabian Westhauser is supported by the“Physician Scientist Program”-scholarship introduced by the Medical Faculty of the University of HeidelbergThis study contains parts of Sarah Isabelle Schmitz's doctoral thesis.
文摘Bioactive glasses(BGs)are promising bone substitute materials.However,under certain circumstances BGs such as the well-known 45S5 Bioglass®(composition in wt%:45.0 SiO2,24.5 Na2O,24.5 CaO,6.0 P2O5)act cytotoxic due to a strong increase in pH caused by a burst release of sodium ions.A potential alternative is a sodiumreduced fluoride-containing BG belonging to the CaO–MgO–SiO2 system,namely BG1d-BG(composition in wt%:46.1 SiO2,28.7 CaO,8.8 MgO,6.2 P2O5,5.7 CaF2,4.5 Na2O),that has already been evaluated in-vitro,in-vivo and in preliminary clinical trials.Before further application,however,BG1d-BG should be compared to the benchmark amongst BGs,the 45S5 Bioglass®composition,to classify its effect on cell viability,proliferation and osteogenic differentiation of human mesenchymal stem cells(MSCs).Therefore,in this study,the biocompatibility and osteogenic potential of both BGs were investigated in an indirect and direct culture setting to assess the effect of the ionic dissolution products and the BGs’physical presence on the cells.The results indicated an advantage of BG1d-BG over 45S5 Bioglass®regarding cell viability and proliferation.Both BGs induced an earlier onset of osteogenic differentiation and accelerated the expression of late osteoblast marker genes compared to the control group.In conclusion,BG1d-BG is an attractive candidate for further experimental investigation.The basic mechanisms behind the different impact on cell behavior should be assessed in further detail,e.g.by further alteration of the BG compositions.
文摘Carbon nanotube reinforced bioglass composites have been successfully synthesized by two comparative sintering techniques, i.e., spark plasma sintering （SPS） and conventional compaction and sinteirng. The composites show improved mechanical properties, with SPS technique substantially better than conventional compact and sintering approach. Using SPS, compared with the 45S5Bioglass matrix, the maximum flexural strength and fracture toughness increased by 159% and 105%, respectively. Enhanced strength and toughness are attributed to the interfacial bonding and bridging effects between the carbon nanotubes and bioglass powders during crack propagations.
文摘As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based on the supposition that the capacity degradation of the binary Mg50Ni50 alloy and ternary Mg45Cu5Ni50 alloy electrodes is solely due to the corrosion of Mg, the active hydrogen storage element. That means amount of capacity degradation is determined by the corrosion current time, which is also the time of operation. The corrosion current J corr dependence on cycling time was deduced. A mathematic relation between the cycling capacity retention C N / C 1 (%) and the duration of operation was also deduced. The data calculated from the equations deduced agree well with those of the experiment result. The loss of the active hydrogen absorbing element Mg is proved to be the main cause for cycling capacity deterioration in the present investigation.
