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
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
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
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.
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.
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.
