Physicochemical and Antibacterial Properties of Bivalent Freeze and Furnace Dried Nanoscale Cerium Oxide
Physicochemical and Antibacterial Properties of Bivalent Freeze and Furnace Dried Nanoscale Cerium Oxide
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DOI：
10.21203/rs.3.rs-136744/v1
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发表时间：
2020-12
期刊：
影响因子：
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通讯作者：
N. Iqbal;A. Anastasiou;Z. Aslam;Mostafa El Raif;T. Do;P. Giannoudis;A. Jha
中科院分区：
文献类型：
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作者：
N. Iqbal;A. Anastasiou;Z. Aslam;Mostafa El Raif;T. Do;P. Giannoudis;A. Jha
骨愈合是一个复杂的过程，如果不加以管理，可能导致细菌感染、骨不连和骨愈合受损。抗生素的广泛过度使用导致了抗药性细菌的出现。由于减少对抗生素药物依赖的紧迫性日益增加，替代治疗策略，包括使用纳米颗粒，引起了人们的极大关注。通过氢氧化物介导的方法合成的二价氧化铈纳米颗粒（Ce 4+和Ce 3+）在280、385和815 ℃下煅烧，使用同时热分析技术鉴定。所得的纳米粒子的特征在于使用X-射线粉末衍射，傅里叶变换红外光谱，紫外-可见光谱，透射电子显微镜，和电子能量损失光谱。氧化铈纳米颗粒的抗菌潜力对应于颗粒大小和萤石晶体结构中氧空位的存在。在50、100和200 μg/ml的浓度下表征纳米颗粒的抗菌功效，并通过测定半数最大抑制浓度（IC 50）来测试针对以下菌株的抗菌功效：大肠杆菌、表皮葡萄球菌和铜绿假单胞菌。煅烧温度影响团聚倾向、粒度分布和Ce 3+：Ce 4+氧化态的比例。氢氧化物介导的方法产生球形二氧化铈纳米颗粒，其粒径范围为4 nm至53 nm。与仅由Ce 4+离子组成的纳米颗粒（即在815 ℃下煅烧的纳米颗粒）相比，冷冻干燥的二价纳米颗粒对大肠杆菌、铜绿假单胞菌和表皮葡萄球菌的抗菌效力分别增加18.5 ± 1.2%、10.5 ± 4.4%和13.8 ± 5.8%。
Bone healing is a complex process, and if not managed, can lead to bacterial infections, non-union and compromised healing of bone. The broad overuse of antibiotics has led to the emergence of antibiotic-resistant bacteria. Due to the growing urgency to minimise the dependency on antibiotic drugs, alternative treatment strategies, including the use of nanoparticles, have attracted significant attention. Bivalent cerium oxide nanoparticles (Ce4+ and Ce3+) synthesised via a hydroxide mediated approach were calcined at 280, 385 and 815 ˚C identified using the Simultaneous Thermal Analysis technique. The resulting nanoparticles were characterised using X-ray Powder Diffraction, Fourier Transform Infrared Spectroscopy, Ultraviolet-Visible Spectroscopy, Transmission Electron Microscopy, and Electron Energy Loss Spectroscopy. The antibacterial potential of cerium oxide nanoparticles corresponds to the particle size and the presence of oxygen vacancies in the fluorite crystal structure. The antibacterial efficacy of nanoparticles was characterised at concentrations of 50, 100 and 200 µg/ml and tested against the following strains, Escherichia coli, Staphylococcus epidermis and Pseudomonas aeruginosa by determining the half-maximal inhibitory concentration (IC50). The calcination temperature was found to affect the agglomeration tendency, particle size distribution and the ratio of Ce3+:Ce4+ oxidation states. The hydroxide mediated approach yielded spherical nanoparticles of ceria with particles size ranging from 4 nm to 53 nm. The freeze-dried bivalent nanoparticles exhibited 18.5 ± 1.2%, 10.5 ± 4.4%, and 13.8 ± 5.8% increased antibacterial efficacy against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus epidermis, respectively compared to nanoparticles consisting solely of Ce4+ ions, i.e. nanoparticles calcined at 815 ˚C.