| Autor: |
Fadeeva IV; A.A. Baikov Institute of Metallurgy and Material Science, Russian Academy of Sciences, Leninsky Prospect 49, 119334 Moscow, Russia., Deyneko DV; Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia.; Laboratory of Arctic Mineralogy and Material Sciences, Kola Science Centre, Russian Academy of Sciences, 14 Fersman Str., 184209 Apatity, Russia., Barbaro K; Istituto Zooprofilattico Sperimentale Lazio e Toscana 'M. Aleandri', Via Appia Nuova, 00178 Rome, Italy., Davydova GA; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Moscow, Russia., Sadovnikova MA; Institute of Physics, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia., Murzakhanov FF; Institute of Physics, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia., Fomin AS; A.A. Baikov Institute of Metallurgy and Material Science, Russian Academy of Sciences, Leninsky Prospect 49, 119334 Moscow, Russia., Yankova VG; Institute of Pharmacy, Department of Analytical, Physical and Colloid Chemistry, I.M. Sechenov First Moscow State Medical University, 8 Trubetskaya Street, Build. 2, 119991 Moscow, Russia., Antoniac IV; Faculty of Materials Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei Street, District 6, 060042 Bucharest, Romania., Barinov SM; A.A. Baikov Institute of Metallurgy and Material Science, Russian Academy of Sciences, Leninsky Prospect 49, 119334 Moscow, Russia., Lazoryak BI; Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia., Rau JV; Institute of Pharmacy, Department of Analytical, Physical and Colloid Chemistry, I.M. Sechenov First Moscow State Medical University, 8 Trubetskaya Street, Build. 2, 119991 Moscow, Russia.; Istituto di Struttura Della Materia, Consiglio Nazionale Delle Ricerche (ISM-CNR), Via del Fosso del Cavaliere 100, 00133 Rome, Italy. |
| Abstrakt: |
Gadolinium-containing calcium phosphates are promising contrast agents for various bioimaging modalities. Gadolinium-substituted tricalcium phosphate (TCP) powders with 0.51 wt% of gadolinium (0.01Gd-TCP) and 5.06 wt% of (0.1Gd-TCP) were synthesized by two methods: precipitation from aqueous solutions of salts (1) (Gd-TCP-pc) and mechano-chemical activation (2) (Gd-TCP-ma). The phase composition of the product depends on the synthesis method. The product of synthesis (1) was composed of β -TCP (main phase, 96%), apatite/chlorapatite (2%), and calcium pyrophosphate (2%), after heat treatment at 900 °C. The product of synthesis (2) was represented by β -TCP (main phase, 73%), apatite/chlorapatite (20%), and calcium pyrophosphate (7%), after heat treatment at 900 °C. The substitution of Ca 2+ ions by Gd 3+ in both β -TCP (main phase) and apatite (admixture) phases was proved by the electron paramagnetic resonance technique. The thermal stability and specific surface area of the Gd-TCP powders synthesized by two methods were significantly different. The method of synthesis also influenced the size and morphology of the prepared Gd-TCP powders. In the case of synthesis route (1), powders with particle sizes of tens of nanometers were obtained, while in the case of synthesis (2), the particle size was hundreds of nanometers, as revealed by transmission electron microscopy. The Gd-TCP ceramics microstructure investigated by scanning electron microscopy was different depending on the synthesis route. In the case of (1), ceramics with grains of 1-50 μm, pore sizes of 1-10 µm, and a bending strength of about 30 MPa were obtained; in the case of (2), the ceramics grain size was 0.4-1.4 μm, the pore size was 2 µm, and a bending strength of about 39 MPa was prepared. The antimicrobial activity of powders was tested for four bacteria ( S. aureus , E. coli , S. typhimurium , and E. faecalis ) and one fungus ( C . albicans ), and there was roughly 30% of inhibition of the micro-organism's growth. The metabolic activity of the NCTC L929 cell and viability of the human dental pulp stem cell study demonstrated the absence of toxic effects for all the prepared ceramic materials doped with Gd ions, with no difference for the synthesis route. |
