{"record":{"leader":"cx  r22     2  45","datafield":[{"ind2":" ","ind1":" ","subfield":{"code":"a","content":"20171021afrey50      ba0"},"tag":100},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":"fre"},{"code":2,"content":"639-2"}],"tag":101},{"ind2":" ","ind1":" ","subfield":{"code":"a","content":2010},"tag":103},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":"k"},{"code":"f","content":"fre"}],"tag":104},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":0},{"code":"b","content":"#"},{"code":"c","content":"#"}],"tag":106},{"ind2":" ","ind1":" ","subfield":{"code":"a","content":"AFNOR"},"tag":152},{"ind2":" ","ind1":" ","subfield":{"code":"a","content":"Oeuvre Textuelle"},"tag":189},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0"},{"code":"t","content":"Élaboration et fonctionnalisation de biocéramiques phosphocalciques"}],"tag":241},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0y"},{"code":"a","content":"La préparation de céramiques phosphocalciques dopées au silicium (Si) a été étudiée sur la base de la formule hypothétique Ca3\u2011x(PO4)2\u20112x(SiO4)x du phosphate tricalcique partiellement substitué par des groupements silicates. Des poudres d\u2019apatite déficitaire en calcium ont été synthétisées en présence de Si par précipitation en milieu aqueux à pH 7 et 30°C. L\u2019augmentation de la teneur en Si accroît la vitesse de réaction de précipitation de l\u2019apatite. Le temps de maturation requis pour obtenir, après calcination des précipités, une poudre constituée d\u2019une phase cristalline unique de phosphate tricalcique beta (β-TCP) diminue avec cette teneur. Des matériaux denses ont été obtenus après frittage naturel à 1100°C pendant 2 h. Le silicium n\u2019est que partiellement incorporé dans la structure du β-TCP, l\u2019excédent se retrouve dans des grains de silice amorphe qui ralentissent le processus de densification. In vitro, des tests d\u2019immersion en solutions salines ont révélé que la présence de Si permettait d\u2019augmenter la bioactivité des céramiques. La biocompatibilité des matériaux a été démontrée par la prolifération des cellules MC3T3-E1 et la différenciation des cellules souches ST-2 a lieu. Le processus de minéralisation osseuse, étudié à l\u2019aide des cellules SaOs-2, est observé sur tous les matériaux et est amélioré en présence de silicium. Dans l\u2019optique d\u2019une fonctionnalisation de surface par des biomolécules, un protocole préliminaire de greffage d\u2019une quantité contrôlée d\u2019organo-alkoxysilane sur la surface d\u2019hydroxyapatite silicatée a été mis en place. Différents facteurs influents dont le pH du milieu réactionnel et la charge de surface des poudres ont ainsi été révélés."}],"tag":300},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0y"},{"code":"a","content":"The preparation of silicon doped calcium phosphate ceramics was studied on the basis of the hypothetical formula Ca3\u2011x(PO4)2\u20112x(SiO4)x of tricalcium phosphate partially substituted by silicate groups. Calcium deficient apatite powders have been synthesised in the presence of silicon by a wet precipitation method at pH 7 and 30°C. The increase of silicon content increased the reaction rate of apatite precipitation. The maturation time required to obtain, after calcination of the precipitate, a powder consisting of a beta tricalcium phosphate (β-TCP) as unique crystalline phase decreased with this content. Dense materials were obtained after natural sintering at 1100°C for 2 h. Silicon was only partially incorporated in the crystal structure of β\u2011TCP, the remaining silicon was in the form of grains of amorphous silica that slow down the densification process. In vitro, immersion tests in saline solutions showed that the bioactivity of the ceramics was improved by silicon. The materials were biocompatible through the MC3T3-E1 culture and the differentiation of ST-2 stem cells occurred well. The bone mineralisation process, evaluated through SaOs-2 cells culture, was observed on all materials and increased in the presence of silicon. For further surface functionalisation with biomolecules, a preliminary study of grafting a controlled amount of organo-alkoxysilane on silicated hydroxyapatite surface was proposed. Different influencing factors including the pH of the system and the charge of the powders surface were highlighted."}],"tag":300},{"ind2":0,"ind1":" ","subfield":[{"code":"b","content":"Thèse de doctorat"},{"code":"c","content":"Matériaux céramiques et traitements de surface"},{"code":"e","content":"Limoges"},{"code":"d","content":2010}],"tag":328},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0"},{"code":"t","content":"Processing and functionalisation of calcium phosphate bioceramics"}],"tag":441},{"ind2":1,"ind1":" ","subfield":[{"code":3,"content":159003237},{"code":7,"content":"ba0yba05"},{"code":"a","content":"Douard"},{"code":"b","content":"Nathalie"},{"code":"f","content":"1984-...."},{"code":4,"content":"070"}],"tag":501},{"ind2":1,"ind1":" ","subfield":[{"code":3,"content":"078137772"},{"code":7,"content":"ba0yba05"},{"code":"a","content":"Champion"},{"code":"b","content":"Éric"},{"code":"f","content":"1963-...."},{"code":4,"content":727}],"tag":501},{"ind2":1,"ind1":" ","subfield":[{"code":3,"content":159003016},{"code":7,"content":"ba0yba05"},{"code":"a","content":"Chotard-Ghodsnia"},{"code":"b","content":"Roxana"},{"code":"f","content":"19..-...."},{"code":4,"content":727}],"tag":501},{"ind2":2,"ind1":0,"subfield":[{"code":3,"content":"026403315"},{"code":7,"content":"ba0yba05"},{"code":"a","content":"Université de Limoges"},{"code":"c","content":"1968-...."},{"code":4,"content":295}],"tag":511},{"ind2":2,"ind1":0,"subfield":[{"code":3,"content":"059358041"},{"code":7,"content":"ba0yba05"},{"code":"a","content":"Université de Limoges"},{"code":"b","content":"Faculté des sciences et techniques"},{"code":4,"content":985}],"tag":511},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":"034232389"},{"code":"a","content":"Poudres céramiques"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":"029677300"},{"code":"a","content":"Biomolécules"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":"030980232"},{"code":"a","content":"Phosphates de calcium"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":"027806839"},{"code":"a","content":"Silicium"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":"034748113"},{"code":"a","content":"Substituts osseux"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":171821343},{"code":"a","content":"Biocéramiques"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0"},{"code":3,"content":"027253139"},{"code":"a","content":"Thèses et écrits académiques"},{"code":2,"content":"rameau"}],"tag":608},{"ind2":" ","ind1":0,"subfield":[{"code":"a","content":"phosphate de calcium silicaté"},{"code":"a","content":"biocéramiques"}],"tag":610},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":530},{"code":2,"content":"TEF"}],"tag":686},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":620},{"code":2,"content":"TEF"}],"tag":686},{"ind2":3,"ind1":" ","subfield":[{"code":"a","content":"FR"},{"code":"b","content":"Abes"},{"code":"c","content":20241127},{"code":"g","content":"AFNOR"}],"tag":801}],"controlfield":[{"tag":"001","content":212769146},{"tag":"003","content":"http://www.idref.fr/212769146"},{"tag":"004","content":20171021},{"tag":"005","content":20241127073832},{"tag":"006","content":"0499"},{"tag":"007","content":"0499"},{"tag":"008","content":"Tr2"}]}}