Fadeeva Inna V, Deyneko Dina V, Barbaro Katia, Davydova Galina A, Sadovnikova Margarita A, Murzakhanov Fadis F, Fomin Alexander S, Yankova Viktoriya G, Antoniac Iulian V, Barinov Sergey M, Lazoryak Bogdan I, Rau Julietta V
A.A. Baikov Institute of Metallurgy and Material Science, Russian Academy of Sciences, Leninsky Prospect 49, 119334 Moscow, Russia.
Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia.
Nanomaterials (Basel). 2022 Mar 3;12(5):852. doi: 10.3390/nano12050852.
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 -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 -TCP (main phase, 73%), apatite/chlorapatite (20%), and calcium pyrophosphate (7%), after heat treatment at 900 °C. The substitution of Ca ions by Gd in both -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 (, , , and ) and one fungus (), 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.
含钆的磷酸钙是用于各种生物成像模态的有前景的造影剂。通过两种方法合成了钆取代的磷酸三钙（TCP）粉末，其中钆含量为0.51 wt%（0.01Gd-TCP）和5.06 wt%（0.1Gd-TCP）：从盐的水溶液中沉淀（1）（Gd-TCP-pc）和机械化学活化（2）（Gd-TCP-ma）。产物的相组成取决于合成方法。合成（1）的产物在900℃热处理后由β-TCP（主相，96%）、磷灰石/氯磷灰石（2%）和焦磷酸钙（2%）组成。合成（2）的产物在900℃热处理后由β-TCP（主相，73%）、磷灰石/氯磷灰石（20%）和焦磷酸钙（7%）组成。通过电子顺磁共振技术证明了在β-TCP（主相）和磷灰石（杂质）相中Ca离子被Gd取代。两种方法合成的Gd-TCP粉末的热稳定性和比表面积有显著差异。合成方法也影响了所制备的Gd-TCP粉末的尺寸和形态。在合成路线（1）的情况下，获得了粒径为几十纳米的粉末，而在合成（2）的情况下，粒径为几百纳米，这通过透射电子显微镜观察得到。通过扫描电子显微镜研究的Gd-TCP陶瓷微观结构因合成路线而异。在（1）的情况下，获得了晶粒尺寸为1-50μm、孔径为1-10μm且弯曲强度约为30MPa的陶瓷；在（2）的情况下，陶瓷晶粒尺寸为0.4-1.4μm，孔径为2μm，制备的弯曲强度约为39MPa。测试了粉末对四种细菌（、、、和）和一种真菌（）的抗菌活性，微生物生长的抑制率约为30%。对NCTC L929细胞的代谢活性和人牙髓干细胞活力的研究表明，所有制备的掺杂Gd离子的陶瓷材料均无毒性作用，合成路线之间无差异。
