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International audienceBiocomposite of bioactive glass (BG) with chitosan polymer (CH) is prepared by freeze-drying technique. Obtained material is investigated by using several physico-chemical methods. The XRD and FTIR show the interface bonding interactions between glass and polymer. The specific surface and porosity of biocomposite were determined. In vitro assays were employed to evaluate the effect of chitosan addition on the glass by studying the chemical reactivity and bioactivity of the BG and BG/CH biocomposite after soaking in a simulated body fluid (SBF). The obtained results show the formation of a bioactive hydroxycarbonate apatite (HCA) layer and highlight the bioactivity and the kinetics of chemical reactivity of bioactive glass, particularly after association with chitosan. The BG/CH biocomposite has excellent ability to form an apatite layer. Inductively coupled plasma-optical emission spectrometry (ICP-OES) highlights the negative effect of chitosan on the silicon release toward the SBF of bioactive glass when in vitro assays

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Praseodymium orthoferrite nanoparticles were synthesized by a simple co-precipitation method via the hydrolysis of Pr (III) and Fe (III) cations in boiling ethanol with 5% aqueous ammonia. The single-phase PrFeO 3 product formed after annealing the precipitates at 650, 750, and 850 • C for 1 h had an average crystal size of 20-30 nm (XRD, SEM, TEM). The synthesized nanopowders were soft ferromagnetic materials with low coercive force and excessive magnetization values.

Abstarct-A bioactive glass with composition (wt %) 46SiO2 ⋅ 24CaO ⋅ 24Na 2 O ⋅ 6P 2 O 5 was elaborated by melting method. "In vitro" experiments were carried out by soaking of glass samples in a simulated body fluid (SBF) at different times. The obtained results showed the formation of a bioactive hydroxyapatite (HA) layer on the surface of bioactive glass after "in vitro" assays.

The main goal of this study is to elaborate and evaluate the physicochemical properties of the synthetic biphasic calcium phosphate (BCP) powder: an associate compound of hydroxyapatite (HA): Ca10(PO4)6(OH)2 and beta-tricalcium phosphate (β-TCP): Ca3(PO4)2. The new compound BCP has two advantages: high bioactivity (HA) and fast biodegradation (β-TCP). The obtained powder of BCP was prepared by the precipitate method. XRD analysis confirmed the synthetic material contained both HA and β-TCP crystalline phases. SEM images showed that the small particles of HA attached to bigger particles of β-TCP in the structure morphology of BCP. The in vitro experiment was carried out in static condition by soaking of a series of 50 mg BCP powder in 100 ml of simulated body fluid solution at different period of soaking time. The XRD and SEM methods studied the microstructureand chemical bond after soaking. The obtained results confirmed the bioactivity of synthetic BCP material by the formation of a new apatite layer on its surface.

Calcium phosphate ceramics consist of materials such as hydroxyapatite, tricalcium phosphate (TCP), calcium phosphate cement (CPC), biphasic calcium phosphate, etc. CPCs have been used for filling bone defects in dentistry and orthopedics. Among these materials, β-tricalcium phosphate is suggestedas an ideal candidate for bone graft in hard tissue engineering due to its high biocompatibility, bioactivity and bone bonding. The preparation, as well as the application of this powder material, has been the important topic of research in material science. In this paper, β-tricalcium phosphate (β-TCP), a component that has chemical formulation similar to bone structure, was synthesized by the precipitate method and then calcinated at 1000oC for 5 h. The physico-chemical properties of synthetic material were examined by XRD, FT-IR and SEM methods. In vitro experience was also carried by soaking β-TCP simulated body fluid powder in a different period of time. Obtained results confirmed the quality of β-TCP synthetic material and its bioactivity.

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