Phosphate-mineralization microbe was chosen to study the influences of bacterial mixture,filtrate,bacteria solution,bacterial body and bacterial secretion on barium hydrogen phosphate crystal formation.The chemical co...Phosphate-mineralization microbe was chosen to study the influences of bacterial mixture,filtrate,bacteria solution,bacterial body and bacterial secretion on barium hydrogen phosphate crystal formation.The chemical compositions and structures of samples were characterized with scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,and X-ray diffraction techniques（XRD）,revealing that the crystal morphology of barium hydrogen phosphate was dumbbell-shaped pattern,nanoparticles via aggregate clusters,irregular sphere with different sizes.The results indicated that bacterial body and bacterial secretion could induce the formation of irregular quadrilateral and spheres,respectively.But the effect of bacterial secretion was stronger than that of bacterial body when induced barium hydrogen phosphate crystal in bacteria solution.However,the crystals form could be affected only in bacterial mixture,but filtrate could induce the formation of nanoparticles.As a result,the bacteria and metabolites play an important role in the process of crystal nucleation,growth,and accumulation of barium hydrogen phosphate.展开更多
A phosphate-mineralization microbe was used to induce barium phosphates precipitation, and the precipitates with different types were obtained under different pH values. The average crystallite size of the barium phos...A phosphate-mineralization microbe was used to induce barium phosphates precipitation, and the precipitates with different types were obtained under different pH values. The average crystallite size of the barium phosphates was calculated by particle size distribution curves, and the size of the products was 33.40, 29. 37, 24. 13, 47.76 and 96. 53 μm when the pH values of the mixed solution are 7, 8, 9, 10 and 11, respectively. The results of X-ray diffraction （XRD） show that the structures of the particles controlled by the mixed solution are mainly BaaPO4 when pH 〈 10; the barium phosphates are synthesized by biological deposition which is the mixture of BaHPO4 and Ba5 （PO4）3OH when pH = 10; when pH = 11, the barium phosphates are also the mixtures, which are Ba5 （PO4）3OH and BaNaPO4. The above results indicate that the phosphate-mineralization microbe can produce a certain enzyme which constantly hydrolyzes phosphate monoester in the mixed solution, and then PO4^3- ions are obtained.展开更多
Rat calvarial osteoblasts were treated with lanthanum chloride（LaCl3） to explore its effect on the mineral crystalline phase during the process of osteoblast calcification in uitro.The results confirmed that La was ...Rat calvarial osteoblasts were treated with lanthanum chloride（LaCl3） to explore its effect on the mineral crystalline phase during the process of osteoblast calcification in uitro.The results confirmed that La was readily deposited in the mineral component of the matrix.Employing high-resolution transmission electron microscopy and Fourier transform infrared microspectroscopy techniques,we demonstrated that features comparable to dicalcium phosphate dihydrate（DCPD） and octacalcium phosphate,and hydroxyapatite（HAP） were detected in the mineral phases in uitro.Particularly,LaCl3 treatment retarded conversion from DCPD-like phase into HAP during mineralization.In addition,La was introduced in DCPD powder during wet chemical synthesis.When compared with that of La-free DCPD,the dissolution rate of La-incorporated DCPD was lower,thereby leading to a delayed DCPD-to-HAP phase transformation.Thus,it can be concluded that LaCl3 treatment influences the kinetics of inorganic phase transition by decreasing the dissolution rate of DCPD.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.5137203851178104)+1 种基金Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1453)333 Project of Jiangsu Province
文摘Phosphate-mineralization microbe was chosen to study the influences of bacterial mixture,filtrate,bacteria solution,bacterial body and bacterial secretion on barium hydrogen phosphate crystal formation.The chemical compositions and structures of samples were characterized with scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,and X-ray diffraction techniques（XRD）,revealing that the crystal morphology of barium hydrogen phosphate was dumbbell-shaped pattern,nanoparticles via aggregate clusters,irregular sphere with different sizes.The results indicated that bacterial body and bacterial secretion could induce the formation of irregular quadrilateral and spheres,respectively.But the effect of bacterial secretion was stronger than that of bacterial body when induced barium hydrogen phosphate crystal in bacteria solution.However,the crystals form could be affected only in bacterial mixture,but filtrate could induce the formation of nanoparticles.As a result,the bacteria and metabolites play an important role in the process of crystal nucleation,growth,and accumulation of barium hydrogen phosphate.
基金The National Natural Science Foundation of China(No.51372038No.51178104)+1 种基金the Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1453)the 333 Project of Jiangsu Province
文摘A phosphate-mineralization microbe was used to induce barium phosphates precipitation, and the precipitates with different types were obtained under different pH values. The average crystallite size of the barium phosphates was calculated by particle size distribution curves, and the size of the products was 33.40, 29. 37, 24. 13, 47.76 and 96. 53 μm when the pH values of the mixed solution are 7, 8, 9, 10 and 11, respectively. The results of X-ray diffraction （XRD） show that the structures of the particles controlled by the mixed solution are mainly BaaPO4 when pH 〈 10; the barium phosphates are synthesized by biological deposition which is the mixture of BaHPO4 and Ba5 （PO4）3OH when pH = 10; when pH = 11, the barium phosphates are also the mixtures, which are Ba5 （PO4）3OH and BaNaPO4. The above results indicate that the phosphate-mineralization microbe can produce a certain enzyme which constantly hydrolyzes phosphate monoester in the mixed solution, and then PO4^3- ions are obtained.
基金supported by the National Natural Science Foundation of China(No.21101008)
文摘Rat calvarial osteoblasts were treated with lanthanum chloride（LaCl3） to explore its effect on the mineral crystalline phase during the process of osteoblast calcification in uitro.The results confirmed that La was readily deposited in the mineral component of the matrix.Employing high-resolution transmission electron microscopy and Fourier transform infrared microspectroscopy techniques,we demonstrated that features comparable to dicalcium phosphate dihydrate（DCPD） and octacalcium phosphate,and hydroxyapatite（HAP） were detected in the mineral phases in uitro.Particularly,LaCl3 treatment retarded conversion from DCPD-like phase into HAP during mineralization.In addition,La was introduced in DCPD powder during wet chemical synthesis.When compared with that of La-free DCPD,the dissolution rate of La-incorporated DCPD was lower,thereby leading to a delayed DCPD-to-HAP phase transformation.Thus,it can be concluded that LaCl3 treatment influences the kinetics of inorganic phase transition by decreasing the dissolution rate of DCPD.
