Ceramics composites based on hydroxyapatite and calcium alumina phases

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Bioceramic composite materials based on apatite minerals are commonly used for bone tissue replacement. Controlling of the additives and porous structure can increase bioactive properties and improve the mechanical resistance of the final bone scaffolds. Generally, these aspects are important criteria in tissue engineering. The apatite bioactive substance can be used as a single phase material or as a matrix of a composite specia. Although the on-going research is focused on using a combination of inorganic matrix with biodegradable polymeric substances including PLA, chitosan or PCL, the inorganic reinforcement based on newly formed phases between apatite and calcium aluminates are not fully studied. In this work the influence of interaction between calcium aluminates and hydroxyapatite on the final properties of the scaffolds was studied. Calcium aluminate, tricalcium aluminate and calcium hexaaluminate phases were mixed with pre-synthesized hydroxypatite (D50 = 6,26 µm) in various concentrations (10, 5, 1 wt. %). The aqueous suspension (solid to water concentration - 50 – 60 wt. %) was prepared from the mixture by intensive stirring (1 000 rpm). Into homogenous suspension the foaming agent (Schäumungsmittel Flüsig W 53) was added and the in situ foaming process was occurred. Foamed suspension was moulded to Al mould with dimensions 10x10x10 mm. An optimal drying and sintering conditions of foamed samples were determined by heating microscopy and TG-DTA analysis. The phase composition and microstructure of the sintered scaffolds was observed by X-Ray diffraction analysis and scanning electron microscopy, resp. The ability to create a new phase on scaffold surface was tested in vitro by immersion of the samples in the simulated body fluid liquid (Kokubo´s composition). The treated scaffold samples were examined by SEM analysis after 1, 3, 7, 21 and 28 days of immersion to observe the formation of a new phase layer. Simultaneously with the surface monitoring the concentration of important ions (i.e. Ca, P, Al) in the applied SBF solutions was determined.

bioceramic, composites, in situ foaming, SBF

VOJTÍŠEK, J.; MÁSILKO, J.; DRÁBIKOVÁ, J.; BARTONÍČKOVÁ, E.

14. 6. 2019

Turín

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