The inhibition and its mechanism of sodium tripolyphosphate （STP） composited with super plasticizers （SPs） on hydration of α-calcium sulfate hemihydrate were studied by setting time, strength, hydration heat, X-r...The inhibition and its mechanism of sodium tripolyphosphate （STP） composited with super plasticizers （SPs） on hydration of α-calcium sulfate hemihydrate were studied by setting time, strength, hydration heat, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, electronic probe micro analysis （EPMA）, scanning electron microscopy （SEM） and differential scanning calorimeter （DSC） measurements. The experimental results show that compared with STP addition, compositing STP with polycarboxylate （PC） plasticizer, the final setting time is prolonged from 0.5h to 2hs. While formulating STP with naphthalene-based plasticizer （NAP） or sulfonate melamine formaldehyde plasticizer （SMF）, the final setting time is reduced to quarter of an hour. Similar changes can also be found in the rate of exothermic hydration and hydration degree. Formulating STP with suitable addition of PC can enhance the strength, while compositing STP and NAP or SMF weakens the strength. Besides, adding STP or STP and SMF, obvious movement （more than 1ev） of binding energy of Ca2p1/2 and Ca2p3/2 is detected. Compared with STP addition, content of the characteristic element （P） of STP is cut down form 1.1% to 0.49% by compositing STP with SMF. Furthermore, as hydration age increases, hydration inhibition in the presence of admixtures weakens and even disappears within 56 h.展开更多
α-calcium sulfate hemihydrate (α-HH) is known to be suitable for application as bone void filler. High percentage of α-HH is obviously needed for medical applications, especially for implantation. Three commerciall...α-calcium sulfate hemihydrate (α-HH) is known to be suitable for application as bone void filler. High percentage of α-HH is obviously needed for medical applications, especially for implantation. Three commercially available calcium sulfate dihydrates (DH, CaSO4·2H2O) with different sizes and surface morphologies were used as starting materials to synthesize high percentage α-HH via a hydrothermal method. The median particle sizes of the three types of DH were 946.7 μm, 162.4 μm and 62.4 μm, respectively. They were named as DH-L, DH-M and DH-S in this paper. The particle size distribution, morphology and phase composition of the raw materials were evaluated before synthesis. SEM results revealed that DH-L consisted of irregular large particles, while DH-M and DH-S were composed of plate-like particles with some small ones. High percentage HH can be obtained with proper synthesis parameters by hydrothermal method, specifically, 105 °C/90 min for DH-L (achieving 98.8% HH), 105°C/30 min for DH-M (achieving 96.7% HH) and 100°C/45 min for DH-S (achieving 98.4% HH). All the synthesized HH were hexagonal columns, demonstrating that they were α-phase HH. The particle size and morphology of starting material (DH) have significant influences on not only the rate of phase transition but also the morphology of the synthesized α-HH. Calcium sulfate dihydrate cements were prepared by the synthesized α-HH. The highest compressive strength of calcium sulfate dihydrate cement was 17.2 MPa. The results show that the preparation of high percentage α-HH is feasible via a hydrothermal method and the process can be further scaled up to industrial scale production.展开更多
Objective:The as-providedα-calcium sulfate hemihydrate bone repair material exhibits superior degradation properties and osteogenic property to the traditional calcium sulfate bone repair materials. Its effects on th...Objective:The as-providedα-calcium sulfate hemihydrate bone repair material exhibits superior degradation properties and osteogenic property to the traditional calcium sulfate bone repair materials. Its effects on the blood and the biocompatibility were studied to ensure its safety for the bone implantation application.Method: The hemolytic tests were conducted to evaluate the blood compatibility of theα-calcium sulfate hemihydrate. The extracts ofα-calcium sulfate hemihydrate with different concentration reacted with 2% rabbit red blood cell suspension. The existence and morphology of the red blood were observed through naked eye observation and microscope observation. The hemolytic ratios were calculated through the absorbances using a ultraviolet spectrophotometer.Result:It was observed by naked eye that the red blood accumulated at the bottom of the test tubes and the upper liquids were clear, colorless and transparent in the experimental sample. The microscope observation exhibited that the cells of the experimental samples had the normal morphology, no deformed and broken blood sell existed. The hemolytic ratios of the experimental sample were all less than 5%. The hemolytic ratios were increased with the increase of the concentration of the extracts. Conclusions: The hemolytic ratios of the medical -calcium sulfate hemihydrate accorded with the standard ISO/TR7405-1984(E). It could be concluded the material would not cause acute hemolysis. The osteogenic property exhibited dose dependence.展开更多
It is still a huge challenge for bone regenerative biomaterial to balance its mechanical,biological and biodegradable properties.In the present study,a new composite material including treated dentin matrix(TDM)andα-...It is still a huge challenge for bone regenerative biomaterial to balance its mechanical,biological and biodegradable properties.In the present study,a new composite material including treated dentin matrix(TDM)andα-calcium sulphate hemihydrate(α-CSH)was prepared.The optimal composition ratio between TDM andα-CSH was explored.The results indicate that both components were physically mixed and structurally stable.Its compressive strength reaches up to 5.027±0.035 MPa for 50%TDM/α-CSH group,similar to human cancellous bone tissues.Biological experiments results show that TDM/α-CSH composite exhibits excellent biocompatibility and the expression of osteogenic related genes and proteins(ALP,RUNX2,OPN)is significantly increased.In vivo experiments suggest that the addition of TDM for each group(10%,30%,50%)effectively promotes cell proliferation and osteomalacia.In addition,50%of the TDM/α-CSH combination displays optimal osteoconductivity.The novel TDM/α-CSH composite is a good candidate for certain applications in bone tissue engineering.展开更多
The synthesis of α-calcium sulfate hemihydrate (α-CSH) from flue gas desulfurization (FGD)gypsum is a good way to realize the comprehensive utilization of FGD gypsum. To obtainα-CSH with the satisfactory performanc...The synthesis of α-calcium sulfate hemihydrate (α-CSH) from flue gas desulfurization (FGD)gypsum is a good way to realize the comprehensive utilization of FGD gypsum. To obtainα-CSH with the satisfactory performances, a facile hydrothermal-aging pretreatment process for FGD gypsum raw materials was proposed, where FGD gypsum was firstly hydrothermally converted to α-CSH whiskers, and α-CSH whiskers were further hydrated to synthesize CaSO4·2H2O (CSD) by aging under the regulation of N,N'-methylenebisacrylamide (MBA). The effects of aging time, MBA addition, aging temperature, and pH on the morphology of the synthesized CSD were investigated. The synthesized CSD crystals exhibit highly uniform prismatic morphology with the length of ca 100μm and the whiteness of 91.56%. The regulation mechanism of MBA was also illustrated. The synthesized CSD crystals with prismatic morphology were further used as raw materials to synthesize the short columnar α-CSH. The absolute dry compressive strength of paste prepared from the short columnar α-CSH is 40.85 MPa, which reaches α40 strength grade.展开更多
基金Funded by the Major State Basic Research Development Program of China (973 Program) (No. 2009CB623104)the National Technology R&D Program for the 11th Five-year Plan (No. 2006BAJ05B03)
文摘The inhibition and its mechanism of sodium tripolyphosphate （STP） composited with super plasticizers （SPs） on hydration of α-calcium sulfate hemihydrate were studied by setting time, strength, hydration heat, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, electronic probe micro analysis （EPMA）, scanning electron microscopy （SEM） and differential scanning calorimeter （DSC） measurements. The experimental results show that compared with STP addition, compositing STP with polycarboxylate （PC） plasticizer, the final setting time is prolonged from 0.5h to 2hs. While formulating STP with naphthalene-based plasticizer （NAP） or sulfonate melamine formaldehyde plasticizer （SMF）, the final setting time is reduced to quarter of an hour. Similar changes can also be found in the rate of exothermic hydration and hydration degree. Formulating STP with suitable addition of PC can enhance the strength, while compositing STP and NAP or SMF weakens the strength. Besides, adding STP or STP and SMF, obvious movement （more than 1ev） of binding energy of Ca2p1/2 and Ca2p3/2 is detected. Compared with STP addition, content of the characteristic element （P） of STP is cut down form 1.1% to 0.49% by compositing STP with SMF. Furthermore, as hydration age increases, hydration inhibition in the presence of admixtures weakens and even disappears within 56 h.
基金financial support from the Swedish Innovation Agency(VINNOVA)and China Scholarship Council(CSC).
文摘α-calcium sulfate hemihydrate (α-HH) is known to be suitable for application as bone void filler. High percentage of α-HH is obviously needed for medical applications, especially for implantation. Three commercially available calcium sulfate dihydrates (DH, CaSO4·2H2O) with different sizes and surface morphologies were used as starting materials to synthesize high percentage α-HH via a hydrothermal method. The median particle sizes of the three types of DH were 946.7 μm, 162.4 μm and 62.4 μm, respectively. They were named as DH-L, DH-M and DH-S in this paper. The particle size distribution, morphology and phase composition of the raw materials were evaluated before synthesis. SEM results revealed that DH-L consisted of irregular large particles, while DH-M and DH-S were composed of plate-like particles with some small ones. High percentage HH can be obtained with proper synthesis parameters by hydrothermal method, specifically, 105 °C/90 min for DH-L (achieving 98.8% HH), 105°C/30 min for DH-M (achieving 96.7% HH) and 100°C/45 min for DH-S (achieving 98.4% HH). All the synthesized HH were hexagonal columns, demonstrating that they were α-phase HH. The particle size and morphology of starting material (DH) have significant influences on not only the rate of phase transition but also the morphology of the synthesized α-HH. Calcium sulfate dihydrate cements were prepared by the synthesized α-HH. The highest compressive strength of calcium sulfate dihydrate cement was 17.2 MPa. The results show that the preparation of high percentage α-HH is feasible via a hydrothermal method and the process can be further scaled up to industrial scale production.
文摘Objective:The as-providedα-calcium sulfate hemihydrate bone repair material exhibits superior degradation properties and osteogenic property to the traditional calcium sulfate bone repair materials. Its effects on the blood and the biocompatibility were studied to ensure its safety for the bone implantation application.Method: The hemolytic tests were conducted to evaluate the blood compatibility of theα-calcium sulfate hemihydrate. The extracts ofα-calcium sulfate hemihydrate with different concentration reacted with 2% rabbit red blood cell suspension. The existence and morphology of the red blood were observed through naked eye observation and microscope observation. The hemolytic ratios were calculated through the absorbances using a ultraviolet spectrophotometer.Result:It was observed by naked eye that the red blood accumulated at the bottom of the test tubes and the upper liquids were clear, colorless and transparent in the experimental sample. The microscope observation exhibited that the cells of the experimental samples had the normal morphology, no deformed and broken blood sell existed. The hemolytic ratios of the experimental sample were all less than 5%. The hemolytic ratios were increased with the increase of the concentration of the extracts. Conclusions: The hemolytic ratios of the medical -calcium sulfate hemihydrate accorded with the standard ISO/TR7405-1984(E). It could be concluded the material would not cause acute hemolysis. The osteogenic property exhibited dose dependence.
基金the National Natural Science Foundation of China(grant numbers 31670994,U1904145 and 81901039)Nature Science Foundation of Henan Province(grant numbers 182300410340,222300420569)+4 种基金Henan Medical Science and Technology Research Project(grant number SBGJ202002073,SBGJ202002075)Science and Technology Department of Science and Technology Research(grant number 182102310456)Henan Province Middle-Aged And Young Health Science and Technology Innovation Leader Training Project(grant number YXKC2021014)Scientific Research and Innovation Team of The First Affiliated Hospital of Zhengzhou University(grant number QNCXTD2023021)Union project of Medical and Technology Research Program of Henan Province(grant number LHGJ20190191).
文摘It is still a huge challenge for bone regenerative biomaterial to balance its mechanical,biological and biodegradable properties.In the present study,a new composite material including treated dentin matrix(TDM)andα-calcium sulphate hemihydrate(α-CSH)was prepared.The optimal composition ratio between TDM andα-CSH was explored.The results indicate that both components were physically mixed and structurally stable.Its compressive strength reaches up to 5.027±0.035 MPa for 50%TDM/α-CSH group,similar to human cancellous bone tissues.Biological experiments results show that TDM/α-CSH composite exhibits excellent biocompatibility and the expression of osteogenic related genes and proteins(ALP,RUNX2,OPN)is significantly increased.In vivo experiments suggest that the addition of TDM for each group(10%,30%,50%)effectively promotes cell proliferation and osteomalacia.In addition,50%of the TDM/α-CSH combination displays optimal osteoconductivity.The novel TDM/α-CSH composite is a good candidate for certain applications in bone tissue engineering.
基金Funded by National Natural Science Foundation of China(No.22008049)Natural Science Foundation of Hebei Province,China (Nos.B2020202081 and B2018202330)+1 种基金Key Laboratory of Gas Hydrate,Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,China (No.E029kf1601)Research Fund Program of Science and Technology of Colleges and Universities of Hebei Province,China (No.QN2019012)。
文摘The synthesis of α-calcium sulfate hemihydrate (α-CSH) from flue gas desulfurization (FGD)gypsum is a good way to realize the comprehensive utilization of FGD gypsum. To obtainα-CSH with the satisfactory performances, a facile hydrothermal-aging pretreatment process for FGD gypsum raw materials was proposed, where FGD gypsum was firstly hydrothermally converted to α-CSH whiskers, and α-CSH whiskers were further hydrated to synthesize CaSO4·2H2O (CSD) by aging under the regulation of N,N'-methylenebisacrylamide (MBA). The effects of aging time, MBA addition, aging temperature, and pH on the morphology of the synthesized CSD were investigated. The synthesized CSD crystals exhibit highly uniform prismatic morphology with the length of ca 100μm and the whiteness of 91.56%. The regulation mechanism of MBA was also illustrated. The synthesized CSD crystals with prismatic morphology were further used as raw materials to synthesize the short columnar α-CSH. The absolute dry compressive strength of paste prepared from the short columnar α-CSH is 40.85 MPa, which reaches α40 strength grade.
