The electrical characterization of bone is essential for the better understanding of the role of electrical stimulation in bone remodeling. Calcium Hydrogen Phosphate Dihydrate or brushite (CaHPO4 2H2O) has been used ...The electrical characterization of bone is essential for the better understanding of the role of electrical stimulation in bone remodeling. Calcium Hydrogen Phosphate Dihydrate or brushite (CaHPO4 2H2O) has been used in bone substitution owing to their fast resorption under physiological condition. Brushite is a suitable matrix for osteoconductive bone grafts. In this work, Calcium Hydrogen Phosphate single crystals have been grown by single diffusion gel growth technique. The powder XRD studies revealed the monoclinic structure of the grown crystals. The vibrational analysis of the crystals is done with FTIR spectroscopy and the major functional groups and their assigned vibrations are discussed. The frequency dependence of dielectric constant and ac conductivity at different temperatures have been studied in detail. This study shows decrease in the dielectric constant with the increase in frequency and temperature. The variation of ac conductivity is found to be increasing with frequency and decreasing with temperature.展开更多
We report in situ doping of brushite on zinc manganese oxide（ZMO）, fabricated by calcining a Mn（II） oxalate‐impregnated metal‐organic framework. The doping process was conducted in com‐bination with the photoca...We report in situ doping of brushite on zinc manganese oxide（ZMO）, fabricated by calcining a Mn（II） oxalate‐impregnated metal‐organic framework. The doping process was conducted in com‐bination with the photocatalytic water oxidation reaction which was catalyzed by ZMO in neutral phosphate‐buffered aqueous solution containing [Ru（bpy）3]^2＋‐Na2S2O8 and calcium（II） triflate salt, exhibiting greatly enhanced water oxidation performance with optimized turnover frequency of 0.18 mmol（O2） mol（Mn）^（–1） s^（–1）. Different analytical techniques indicated that photodeposited calci‐um‐phosphate（CaP） acted as a co‐catalyst to promote the O2 evolution activity of ZMO. This system involved the use of manganese oxide and calcium ion, and the operation was conducted under am‐bient temperature and neutral conditions, thus, it efficiently mimicked the oxygen‐evolving complex in photosystem II.展开更多
For the past several years,calcium phosphate cement was used in the biomedical applications.Outstanding biocompatibility,good bioactivity,self-setting qualities,minimum setting degree,appropriate toughness,and simple ...For the past several years,calcium phosphate cement was used in the biomedical applications.Outstanding biocompatibility,good bioactivity,self-setting qualities,minimum setting degree,appropriate toughness,and simple shape to accommodate any difficult geometry are among their most notable attributes.Calcium phosphate has some types and brushite is one of the most attractive mineral for bone repair application.Brushite is extensively employed in filling fractures and trauma treatments as a bone substituted material.This kind of material can potentially be used as a medicine delivery device.The replacement of metal,such as magnesium,zinc,and strontium ions,into the calcium phosphate structure is a major research topic these days.Brushite cement has low mechanical strength and quick setting rate.It is possible to produce biomaterials with higher mechanical characteristics.By adding metal that are great potential in controlling cellular density when included into biomaterials.As a result,it is a successful method to develop quite well regenerative medicine.This paper provides a detailed summary of the present achievements of metal-doped brushite cement for bone repair and healing process.The major purpose of this work is to give a simple but thorough analysis of current successes in brushite cement doped with Zn,Mg,Sr,and other ions as well as to highlight new advancements and prospects.The impact of metal replacement on cement physical and chemical properties,including microstructure,setting time,injectability,mechanical property,and ion release,is explored.The metal-doped cement has osteogenesis,angiogenesis,and antibacterial properties,as well as their prospective utility as drug carriers,also considered.展开更多
This study investigated the osteogenic performance of new brushite cements obtained from Li+-dopedβ-tricalcium phosphate as a promising strategy for bone regeneration.Lithium(Li+)is a promising trace element to encou...This study investigated the osteogenic performance of new brushite cements obtained from Li+-dopedβ-tricalcium phosphate as a promising strategy for bone regeneration.Lithium(Li+)is a promising trace element to encourage the migration and proliferation of adipose-derived stem cells(hASCs)and the osteogenic differentiation-related gene expression,essential for osteogenesis.In-situ X-ray diffraction(XRD)and in-situ 1H nuclear magnetic resonance(1H NMR)measurements proved the precipitation of brushite,as main phase,and monetite,indicating that Li+favored the formation of monetite under certain conditions.Li+was detected in the remaining pore solution in significant amounts after the completion of hydration.Isothermal calorimetry results showed an accelerating effect of Li+,especially for low concentration of the setting retarder(phytic acid).A decrease of initial and final setting times with increasing amount of Li+was detected and setting times could be well adjusted by varying the setting retarder concentration.The cements presented compressive mechanical strength within the ranges reported for cancellous bone.In vitro assays using hASCs showed normal metabolic and proliferative levels.The immunodetection and gene expression profile of osteogenic-related markers highlight the incorporation of Li+for increasing the in vivo bone density.The osteogenic potential of Li-doped brushite cements may be recommended for further research on bone defect repair strategies.展开更多
文摘The electrical characterization of bone is essential for the better understanding of the role of electrical stimulation in bone remodeling. Calcium Hydrogen Phosphate Dihydrate or brushite (CaHPO4 2H2O) has been used in bone substitution owing to their fast resorption under physiological condition. Brushite is a suitable matrix for osteoconductive bone grafts. In this work, Calcium Hydrogen Phosphate single crystals have been grown by single diffusion gel growth technique. The powder XRD studies revealed the monoclinic structure of the grown crystals. The vibrational analysis of the crystals is done with FTIR spectroscopy and the major functional groups and their assigned vibrations are discussed. The frequency dependence of dielectric constant and ac conductivity at different temperatures have been studied in detail. This study shows decrease in the dielectric constant with the increase in frequency and temperature. The variation of ac conductivity is found to be increasing with frequency and decreasing with temperature.
文摘We report in situ doping of brushite on zinc manganese oxide（ZMO）, fabricated by calcining a Mn（II） oxalate‐impregnated metal‐organic framework. The doping process was conducted in com‐bination with the photocatalytic water oxidation reaction which was catalyzed by ZMO in neutral phosphate‐buffered aqueous solution containing [Ru（bpy）3]^2＋‐Na2S2O8 and calcium（II） triflate salt, exhibiting greatly enhanced water oxidation performance with optimized turnover frequency of 0.18 mmol（O2） mol（Mn）^（–1） s^（–1）. Different analytical techniques indicated that photodeposited calci‐um‐phosphate（CaP） acted as a co‐catalyst to promote the O2 evolution activity of ZMO. This system involved the use of manganese oxide and calcium ion, and the operation was conducted under am‐bient temperature and neutral conditions, thus, it efficiently mimicked the oxygen‐evolving complex in photosystem II.
基金The authors are grateful to the University of Engineering and Technology,Lahore,Pakistan(ORIC/99 ASRB-614)for funding this research.
文摘For the past several years,calcium phosphate cement was used in the biomedical applications.Outstanding biocompatibility,good bioactivity,self-setting qualities,minimum setting degree,appropriate toughness,and simple shape to accommodate any difficult geometry are among their most notable attributes.Calcium phosphate has some types and brushite is one of the most attractive mineral for bone repair application.Brushite is extensively employed in filling fractures and trauma treatments as a bone substituted material.This kind of material can potentially be used as a medicine delivery device.The replacement of metal,such as magnesium,zinc,and strontium ions,into the calcium phosphate structure is a major research topic these days.Brushite cement has low mechanical strength and quick setting rate.It is possible to produce biomaterials with higher mechanical characteristics.By adding metal that are great potential in controlling cellular density when included into biomaterials.As a result,it is a successful method to develop quite well regenerative medicine.This paper provides a detailed summary of the present achievements of metal-doped brushite cement for bone repair and healing process.The major purpose of this work is to give a simple but thorough analysis of current successes in brushite cement doped with Zn,Mg,Sr,and other ions as well as to highlight new advancements and prospects.The impact of metal replacement on cement physical and chemical properties,including microstructure,setting time,injectability,mechanical property,and ion release,is explored.The metal-doped cement has osteogenesis,angiogenesis,and antibacterial properties,as well as their prospective utility as drug carriers,also considered.
文摘 通过声电沉积工艺在炭 炭复合材料表面制备了生物活性透钙磷石涂层,用XRD、EDAX及Raman光谱对炭 炭复合材料改性前后的表面特征进行了研究。结果表明,与传统电结晶工艺相比,声电沉积工艺所制透钙磷石涂层晶面间距减小,炭 炭复合材料与透钙磷石涂层间形成了C O P、C O H等化学键合。同时探讨了成键机理,认为声电沉积工艺是声电表面改性、声化学合成以及电结晶工艺的有机组合。
基金funded by the Portuguese Foundation for Science and Technology(FCT)and the German Academic Exchange Service(Deutscher Akademischer Austauschdienst,DAAD)for the transnational cooperation FCT/DAAD 2018-2019FRM acknowledges her contract under the Transitional Rule DL 57/2016(CTTI-57/18-I3BS(5))attributed by the FCT.VPR acknowledges the Junior Researcher contracts(POCI-01-0145-FEDER-031367+1 种基金POCI-01-0145-FEDER-029139)under the projects Fun4TE project(PTDC/EMD-EMD/31367/2017)and B-Liver(PTDC/EMD-EMD/29139/2017)attributed by the FCT.The authors also thank the funds provided under the distinctions attributed to JMO(IF/01285/2015)and SP(CEECIND/03673/2017).Furthermore,funding by the German Research Foundation(Deutsche Forschungsgemeinschaft,DFG),Grant Nr.HU 2498/1-1GB 1/22-1,is acknowledged.
文摘This study investigated the osteogenic performance of new brushite cements obtained from Li+-dopedβ-tricalcium phosphate as a promising strategy for bone regeneration.Lithium(Li+)is a promising trace element to encourage the migration and proliferation of adipose-derived stem cells(hASCs)and the osteogenic differentiation-related gene expression,essential for osteogenesis.In-situ X-ray diffraction(XRD)and in-situ 1H nuclear magnetic resonance(1H NMR)measurements proved the precipitation of brushite,as main phase,and monetite,indicating that Li+favored the formation of monetite under certain conditions.Li+was detected in the remaining pore solution in significant amounts after the completion of hydration.Isothermal calorimetry results showed an accelerating effect of Li+,especially for low concentration of the setting retarder(phytic acid).A decrease of initial and final setting times with increasing amount of Li+was detected and setting times could be well adjusted by varying the setting retarder concentration.The cements presented compressive mechanical strength within the ranges reported for cancellous bone.In vitro assays using hASCs showed normal metabolic and proliferative levels.The immunodetection and gene expression profile of osteogenic-related markers highlight the incorporation of Li+for increasing the in vivo bone density.The osteogenic potential of Li-doped brushite cements may be recommended for further research on bone defect repair strategies.
