title: A new sol-gel synthesis of 45S5 bioactive glass using an organic acid as catalyst.
abstract: In this paper a new sol-gel approach was explored for the synthesis of the 45S5 bioactive glass. We demonstrate that citric acid can be used instead of the usual nitric acid to catalyze the sol-gel reactions. The substitution of nitric acid by citric acid allows to reduce strongly the concentration of the acid solution necessary to catalyze the hydrolysis of silicon and phosphorus alkoxides. Two sol-gel powders with chemical compositions very close to that of the 45S5 were obtained by using either a 2M nitric acid solution or either a 5mM citric acid solution. These powders were characterized and compared to the commercial Bioglass®. The surface properties of the two bioglass powders were assessed by scanning electron microscopy (SEM) and by Brunauer-Emmett-Teller method (BET). The Fourier transformed infrared spectroscopy (FTIR) and the X-ray diffraction (XRD) revealed a partial crystallization associated to the formation of crystalline phases on the two sol-gel powders. The in vitro bioactivity was then studied at the key times during the first hours of immersion into acellular Simulated Body Fluid (SBF). After 4h immersion into SBF we clearly demonstrate that the bioactivity level of the two sol-gel powders is similar and much higher than that of the commercial Bioglass®. This bioactivity improvement is associated to the increase of the porosity and the specific surface area of the powders synthesized by the sol-gel process. Moreover, the nitric acid is efficiently substituted by the citric acid to catalyze the sol-gel reactions without alteration of the bioactivity of the 45S5 bioactive glass.
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2, France. Electronic address: joel.faure@univ-reims.fr.
authors.forename: J
authors.initials: J
authors.lastname: Faure
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2, France. Electronic address: richard.drevet@univ-reims.fr.
authors.forename: R
authors.initials: R
authors.lastname: Drevet
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2, France.
authors.forename: A
authors.initials: A
authors.lastname: Lemelle
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2, France.
authors.forename: N
authors.initials: N
authors.lastname: Ben Jaber
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2, France.
authors.forename: A
authors.initials: A
authors.lastname: Tara
authors.affiliation: Université de Reims Champagne-Ardenne UMR CNRS MEDyC, EA 7369, Campus Moulin de la Housse, 51687 REIMS Cedex 2, France.
authors.forename: H
authors.initials: H
authors.lastname: El Btaouri
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2, France.
authors.forename: H
authors.initials: H
authors.lastname: Benhayoune
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry; D002384:Catalysis; D002516:Ceramics / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods; D017942:Nitric Acid / Q000737:chemistry*; D016062:Porosity; D011208:Powders / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D001672:Biocompatible Materials; D011208:Powders; D012996:Solutions; C425330:bioactive glass 45S5; D019343:Citric Acid; D017942:Nitric Acid
keywords: 45S5; Bioactive glass; Bioactivity; Citric acid; In vitro tests; Sol–gel