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Release of PLGA-encapsulated dexamethasone from microsphere loaded porous surfaces.

Dawes GJ, Fratila-Apachitei LE, Necula BS, Apachitei I, Witkamp GJ, Duszczyk J - J Mater Sci Mater Med (2009)

Bottom Line: The scanning electron microscopy investigations revealed that the size distribution and morphology of the attached spheres had not changed significantly.The only significant change was an increased release rate during the first 100 h.This difference was attributed to the effect of thermal attachment of the spheres to the surface.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, Delft University of Technology, Delft, The Netherlands. G.J.S.Dawes@tudelft.nl

ABSTRACT
The aim of the present study was to investigate the morphology and function of a drug eluting metallic porous surface produced by the immobilization of poly lactide-co-glycolide microspheres bearing dexamethasone onto plasma electrolytically oxidized Ti-6Al-7Nb medical alloy. Spheres of 20 microm diameter were produced by an oil-in-water emulsion/solvent evaporation method and thermally immobilized onto titanium discs. The scanning electron microscopy investigations revealed that the size distribution and morphology of the attached spheres had not changed significantly. The drug release profiles following degradation in phosphate buffered saline for 1000 h showed that, upon immobilisation, the spheres maintained a sustained release, with a triphasic profile similar to the non-attached system. The only significant change was an increased release rate during the first 100 h. This difference was attributed to the effect of thermal attachment of the spheres to the surface.

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Morphology of the immobilized PLGA spheres visualized by scanning electron microscopy: a 20 μm spheres on an oxidised titanium surface (15 kV, ×1000); b 20 μm spheres on a non-oxidised titanium surface (5 kV, ×1000)
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Fig1: Morphology of the immobilized PLGA spheres visualized by scanning electron microscopy: a 20 μm spheres on an oxidised titanium surface (15 kV, ×1000); b 20 μm spheres on a non-oxidised titanium surface (5 kV, ×1000)

Mentions: As found in our previous work [27], the applied microsphere synthesis scheme led to spheres produced of approximately 20 μm diameter. Typical SEM images of the spheres attached to oxidised and non-oxidised titanium are shown in Fig. 1. A slight union between nearby spheres or partial melting of the spheres (Fig. 1a), showed the effect of thermal treatment onto the surface. This evidence suggests that the spheres are lightly attached to the titanium oxide surface texture. Areas with agglomerated spheres were occasionally observed. The distribution of sphere sizes after thermal attachment to the titanium oxide surface can be seen in Fig. 2. Before thermal treatment, the average diameter was 20 ± 10 μm [27], whilst after thermal treatment the sphere diameters were found to be 26 ± 10 μm. These overlapping figures indicate that no significant change in diameter or shape of the spheres occurred due to thermal treatment.Fig. 1


Release of PLGA-encapsulated dexamethasone from microsphere loaded porous surfaces.

Dawes GJ, Fratila-Apachitei LE, Necula BS, Apachitei I, Witkamp GJ, Duszczyk J - J Mater Sci Mater Med (2009)

Morphology of the immobilized PLGA spheres visualized by scanning electron microscopy: a 20 μm spheres on an oxidised titanium surface (15 kV, ×1000); b 20 μm spheres on a non-oxidised titanium surface (5 kV, ×1000)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2805798&req=5

Fig1: Morphology of the immobilized PLGA spheres visualized by scanning electron microscopy: a 20 μm spheres on an oxidised titanium surface (15 kV, ×1000); b 20 μm spheres on a non-oxidised titanium surface (5 kV, ×1000)
Mentions: As found in our previous work [27], the applied microsphere synthesis scheme led to spheres produced of approximately 20 μm diameter. Typical SEM images of the spheres attached to oxidised and non-oxidised titanium are shown in Fig. 1. A slight union between nearby spheres or partial melting of the spheres (Fig. 1a), showed the effect of thermal treatment onto the surface. This evidence suggests that the spheres are lightly attached to the titanium oxide surface texture. Areas with agglomerated spheres were occasionally observed. The distribution of sphere sizes after thermal attachment to the titanium oxide surface can be seen in Fig. 2. Before thermal treatment, the average diameter was 20 ± 10 μm [27], whilst after thermal treatment the sphere diameters were found to be 26 ± 10 μm. These overlapping figures indicate that no significant change in diameter or shape of the spheres occurred due to thermal treatment.Fig. 1

Bottom Line: The scanning electron microscopy investigations revealed that the size distribution and morphology of the attached spheres had not changed significantly.The only significant change was an increased release rate during the first 100 h.This difference was attributed to the effect of thermal attachment of the spheres to the surface.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, Delft University of Technology, Delft, The Netherlands. G.J.S.Dawes@tudelft.nl

ABSTRACT
The aim of the present study was to investigate the morphology and function of a drug eluting metallic porous surface produced by the immobilization of poly lactide-co-glycolide microspheres bearing dexamethasone onto plasma electrolytically oxidized Ti-6Al-7Nb medical alloy. Spheres of 20 microm diameter were produced by an oil-in-water emulsion/solvent evaporation method and thermally immobilized onto titanium discs. The scanning electron microscopy investigations revealed that the size distribution and morphology of the attached spheres had not changed significantly. The drug release profiles following degradation in phosphate buffered saline for 1000 h showed that, upon immobilisation, the spheres maintained a sustained release, with a triphasic profile similar to the non-attached system. The only significant change was an increased release rate during the first 100 h. This difference was attributed to the effect of thermal attachment of the spheres to the surface.

Show MeSH