No abstract

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/eng/view/object/?id=90c0c36d-743d-4b59-8cd5-38ea2fcab383 http://nparc.cisti-icist.nrc-cnrc.gc.ca/fra/voir/objet/?id=90c0c36d-743d-4b59-8cd5-38ea2fcab383 ABSTRACTIn this paper, the compressive strength and in vitro bioactivity of sintered 45S5 bioactive glass scaffolds produced by powder technology and polymer foaming were investigated. The sintering temperature of scaffolds was 975°C. The characterization of scaffolds before immersion in SBF was performed by scanning electron microscopy (SEM) and microtomography (μCT). The scaffolds were also tested for compression, and their density and porosity were measured. After immersion, the samples were observed through SEM and analyzed using EDS, X-ray diffraction (XRD), and infrared spectroscopy (FT-IR). Mass variation was also estimated. The glass-ceramic scaffolds showed a 61.44 ± 3.13% interconnected porosity and an average compressive strength of 13.78 ± 2.43 MPa. They also showed the formation of a hydroxyapatite layer after seven days of immersion in SBF, demonstrating that partial crystallization during sintering did not suppress their bioactivity.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microsphere loaded 45S5 bioactive glass (BG) based scaffolds with drug releasing capability have been developed. PHBV microspheres with a mean particle size 4 ± 2 μm loaded with daidzein were obtained by oil-in-water single emulsion solvent evaporation method and applied to the surface of BG scaffolds by dip coating technique. The morphology, in vitro bioactivity in simulated body fluid (SBF), mechanical properties and drug release kinetics of microsphere loaded scaffolds were studied. The microspheres were shown to be homogeneously dispersed on the scaffold surfaces. It was confirmed that hydroxyapatite crystals homogeneously grew not only on the surface of the scaffold but also on the surface of the microspheres within 3 days of immersion in SBF. The daidzein release from the microsphere loaded scaffolds lasted almost 1 month and was determined to be diffusion controlled. The microsphere loaded BG scaffolds with daidzein releasing capability obtained in this study are a candidate for bone tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1765-1774, 2017.

Bioactive glass 45S5 foams were produced as an alternative to be used to fill and restore bone deffects. A crucial design factor of foams is permeability, since it is related to their capability for waste removal and nutrients/oxygen supply to cells. In the present work a study was carried out to analyze the bioactive glass 45S5 foams permeability by Darcy’s law. The measure average permeability value on foams of 69-74 % porosity was 4.19 × 10-10, 3.75 × 10-10 and 3.48 × 10-10 m2, which are in the range of permeability values for trabecular bone.

RESUMENAndamios macroporos de biovidro 45S5 han sido desarrollados como una alternativa para sustituir injertos de hueso tradicionales. Un factor crucial en el diseño de estos andamios es la permeabilidad ya que de esto dependerá su capacidad para remover desechos y suministrar nutrientes y oxígeno a las células. En este trabajo se llevó acabo la evaluación de la permeabilidad basados en la ley de Darcy de andamios macroporos de biovidrio 45S5 con porosidades en el rango de 69%-74%. Los valores de permeabilidad obtenidos fueron de 4.19 × 10 -10 , 3.75 × 10 -10 y 3.48 × 10 -10 m 2 que estuvieron en el rango de los valores de permeabilidad del hueso trabecular.