摘要
背景:由于细菌对抗生素耐药性的发展,多重耐药菌感染的增加已成为现代医疗保健中的主要问题,研发新的抗菌替代药物材料具有重要意义。目的:合成一种CeO_(2)纳米酶并进行一系列表征,研究其生物相容性以及对大肠杆菌的抗菌性能。方法:采用水热法合成CeO_(2)纳米酶,通过X射线衍射、X射线光电子能谱、傅里叶红外分析、拉曼光谱、扫描电镜、透射电镜等表征方法对其形貌、产物成分和化学组成进行分析,利用3,3’,5,5’-四甲基联苯胺(TMB)显色实验对CeO_(2)纳米酶的过氧化物模拟酶活性进行表征。使用CCK-8法评价不同质量浓度(10,25,50μg/mL)CeO_(2)纳米酶对小鼠成纤维细胞L929的毒性作用。使用平板计数法评价CeO_(2)纳米酶在不同条件下对大肠杆菌的抗菌性能,使用活性氧检测试剂盒检测不同条件处理后的细菌内活性氧水平变化。结果与结论:①CeO_(2)纳米酶的形貌为棒状,其中Ce^(3+)占Ce^(3+)和Ce^(4+)总和的29.87%,平均晶粒尺寸为7.4 nm;在pH=5.5、含底物TMB的微酸性环境下,CeO_(2)纳米酶和H_(2)O_(2)混合后表现出优异的过氧化物酶活性,但在pH=7.4的情况下未表现出过氧化物酶模拟活性。②不同质量浓度的CeO_(2)纳米酶对小鼠成纤维细胞L929均无明显的细胞毒性。③在pH=5.5的微酸性环境中,单独存在CeO_(2)纳米酶(10μg/mL)时,大肠杆菌受到一定程度的抑制,CFU结果下降约0.5个log(P<0.01);在含H_(2)O_(2)(50μmol/L)的微酸性环境中,CeO_(2)纳米酶对大肠杆菌表现出优异的抗菌效果,CFU结果下降约1.5个log(P<0.001)。当CeO_(2)纳米酶单独存在时,大肠杆菌中活性氧水平升高(P<0.05);当CeO_(2)纳米酶与H_(2)O_(2)共同存在时,大肠杆菌中活性氧水平显著升高(P<0.001)。④结果表明,CeO_(2)纳米酶具有良好的生物相容性与一定的抗菌能力,可在含低浓度H_(2)O_(2)的微酸性环境下表现出过氧化物酶活性,产生活性氧杀灭细菌,进而表现出更优异的抗菌效果。
BACKGROUND:The increase in multi-drug resistant bacterial infections has become a major problem in modern healthcare due to the development of bacterial resistance to antibiotics and the development of new antibacterial alternative drug materials is of great importance.OBJECTIVE:To synthesize and perform a series of characterization of a CeO_(2)nanoenzyme to investigate its biocompatibility and antibacterial properties against Escherichia coli.METHODS:CeO_(2)nanoenzymes were synthesized using a hydrothermal method.The morphology,product composition,and chemical composition were analyzed using characterization methods such as X-ray diffraction,X-ray photoelectron spectroscopy,Fourier infrared analysis,Raman spectroscopy,scanning electron microscopy,and transmission electron microscopy.The peroxide-mimetic enzyme activity of CeO_(2)nanoenzymes was characterized using TMB color development assay.The toxic effect of CeO_(2)nanoenzymes at different concentrations(10,25,and 50μg/mL)on mouse fibroblast L929 cells was evaluated using the CCK-8 assay.The antibacterial properties of CeO_(2)nanoenzymes against Escherichia coli under different conditions were evaluated using the plate coating method.Changes in intra-bacterial reactive oxygen species after treatment with different conditions were detected using a reactive oxygen species detection kit.RESULTS AND CONCLUSION:(1)The morphology of the synthesized CeO_(2)nanoparticles was rod-shaped,with Ce^(3+)accounting for 29.87%of the total Ce^(3+)/Ce^(4+)and an average grain size of 7.4 nm.In a slightly acidic environment containing TMB and pH=5.5,CeO_(2)nanoenzymes mixed with H_(2)O_(2)showed excellent peroxidase activity,but did not show peroxidase simulated activity at pH=7.4.(2)There was no statistically significant difference in the toxic effects of CeO_(2)nanoparticles at various mass concentrations on mouse fibroblast L929 cells.(3)In a slightly acidic environment at pH 5.5,Escherichia coli was inhibited to a certain extent in the presence of CeO_(2)nanoenzyme alone at a concentration of 10μg/mL,with a decrease in CFU results of about 0.5 log(P<0.01);in a slightly acidic environment containing 50μmol/L H_(2)O_(2),CeO_(2)nanoenzyme showed excellent antibacterial effects against Escherichia coli,with a decrease in Escherichia coli CFU results of by about 1.5 log(P<0.001).After CeO_(2)nanoenzymes interacted with Escherichia coli,the level of reactive oxygen species in Escherichia coli increased(P<0.05);after CeO_(2)nanoenzymes interacted with Escherichia coli together with H_(2)O_(2),the level of reactive oxygen species in Escherichia coli increased significantly(P<0.001).(4)The results show that the CeO_(2)nanoenzymes have good biocompatibility,are inherently antibacterial,and can exhibit peroxidase activity in a slightly acidic environment containing low concentrations of H_(2)O_(2),and generate reactive oxygen species to kill bacteria,thus showing excellent antibacterial effects.
作者
郑黑姝
张映娟
韦艳华
黄辉
马翔宇
廖红兵
Zheng Heishu;Zhang Yingjuan;Wei Yanhua;Huang Hui;Ma Xiangyu;Liao Hongbing(College of Stomatology,Guangxi Medical University/Affiliated Stomatological Hospital,Nanning 530021,Guangxi Zhuang Autonomous Region,China;Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction,Nanning 530021,Guangxi Zhuang Autonomous Region,China;Nanostructured Thermodynamics and Micro-nano Chemical Engineering Laboratory,College of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,Guangxi Zhuang Autonomous Region,China)
出处
《中国组织工程研究》
CAS
北大核心
2024年第22期3496-3501,共6页
Chinese Journal of Tissue Engineering Research
基金
国家自然科学基金资助项目(82160192,81860201),项目负责人:廖红兵。
关键词
氧化铈
纳米酶
纳米材料
抗菌性能
生物相容性
大肠杆菌
cerium oxide
nanoenzyme
nanomaterial
antibacterial property
biocompatibility
Escherichia coli
