Phosphocalcic glasses, based on ternary system SiO2 - CaO- P2O5 and those doped with copper (SiO2 – CaO - P2O5 - Cu2O) can be obtained by the traditional method of sub-cooling melts or modern methods such as process that uses mechanical energy, neutrons action, deposition in thin layers or by sol-gel technique. This paper shows the experimental results of three compositional phosphocalcic glasses: 50% SiO2 - 43% CaO - 7% P2O5, 50% SiO2 - 38% CaO - 7% P2O5 - 5% Cu2O obtained through sol-gel method and 45% SiO2 - 22.5% CaO - 22.5 Na2O - 5% P2O5 - 5% Cu2O obtained by melting. In order to study their bioactivity, the three compositions were structural analyzed by X-ray diffraction method. In this case the apatite formation was highlighted after soaked in simulated body fluid, but also other compounds (CaCO3 and CuO) resulting from the same process were observed. In case of the melting glass apatite formation has not been highlighted. The functional groups present in the structure of glasses before and after soaking (PO43−, CO32− and HO−) were highlighted by the Fourier Transform Infrared Spectroscopy (FTIR). The elemental chemical composition was confirmed by elemental analysis WD-XRF. The morphology of sol-gel glass powders was revealed by SEM analysis. All glass compositions were tested in terms of antibacterial activity in vitro.
Myoglobin, meat pigment is an iron containing protein found in muscle consisting of heme connected to a single proteide chain. Color is the most important factor in meat products influencing the consumer purchase decision and affecting the perception of freshness. This research presents a spectophotometric method tested identify myoglobin in beef, readings being made at several wavelenghts. Oxidation of myoglobin pigment in metmyoglobin, was also analysed using peroxide hydrogene. A considerable decrease of myoglobin compared with the standard sample was observed (approximately 7 times).
In this paper is presented a comparative study regarding the synthesis of hydroxyapatite powders. The chosen method of synthesis of this biomaterial was chemical co-precipitation. The structure, size and morphology of the obtained powders were analyzed by X-ray diffraction, infrared spectroscopy - FTIR, dynamic light diffusion DLS tehnique and scanning electron microscopy-SEM. The results obtained were compared with those obtained on a commercial hydroxyapatite powder. Investigation methods have confirmed the synthesis of a high purity hydroxyapatite with a optimal degree of crystallization and crystallinity for the reconstruction and regeneration of hard tissue.
This paper presents the most used processes for the synthesis of hydroxyapatite from aqueous solutions: chemical precipitation, the hydrothermal process and the sol-gel method. The experimental part includes the synthesis of hydroxyapatite by chemical precipitation. The obtained results confirm the obtaining of a ceramic with a high purity and a high degree of crystallization.