title: Crystallization processes at the surface of polylactic acid-bioactive glass composites during immersion in simulated body fluid.
abstract: We report on the crystallization processes occurring at the surface of PDLLA-Bioglass® composites immersed in simulated body fluid. Composites manufactured by injection molding and containing different amounts (0, 20, 30, and 50 wt %) of 45S5 Bioglass® particles were tested for durations up to 56 days and compared with Bioglass® particles alone. Crystallization processes were followed by visual inspection, X-ray diffraction (with Rietveld analysis) and scanning electron microscopy. Both calcite and hydroxyapatite were formed at the surface of all materials, but their relative ratio was dependent on the Bioglass® content and immersion time. Hydroxyapatite was always the major phase after sufficient immersion time, insuring bioactivity of such composites especially for Bioglass® content higher than 30 wt %. A scenario of crystallization is proposed. Rapid degradation of the composites with 50 wt % was also observed during immersion. Therefore, composites with 30 wt % of Bioglass® particles seem to exhibit the best balance between bioactivity and stability at least during the first weeks of immersion in contact with body fluids.
authors.affiliation: Université de Lyon, CNRS, Villeurbanne, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Ginsac
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Chenal
authors.forename: Sylvain
authors.initials: S
authors.lastname: Meille
authors.forename: Elodie
authors.initials: E
authors.lastname: Pacard
authors.forename: Rachid
authors.initials: R
authors.lastname: Zenati
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Hartmann
authors.forename: Jérôme
authors.initials: J
authors.lastname: Chevalier
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials; D001826:Body Fluids / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D003460:Crystallization; D017886:Durapatite / Q000737:chemistry; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning / Q000379:methods; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; C022107:Bioglass; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D017886:Durapatite