Pavlova Elitsa L, Nenova Elena P, Yocheva Lyubomira D, Ivanova Iliana A, Georgiev Peter A
Faculty of Physics, Sofia University "St. Kliment Ohridski", 5 James Bourchier Blvd, 1164 Sofia, Bulgaria.
Faculty of Biology, Sofia University "St. Kliment Ohridski", 8 Dragan Tsankov Blvd, 1164 Sofia, Bulgaria.
Pharmaceuticals (Basel). 2024 Nov 25;17(12):1586. doi: 10.3390/ph17121586.
The antimicrobial, oxidative activities, and ecotoxicity of synthesized silver-loaded zeolites (X and ZSM-5(MFI), Si-to-Al ratios 12 and 25) were studied, linking antimicrobial properties to material structure and released active silver species.
The materials were characterized by SEM, EDX, TEM, and XRPD. All materials, with a silver content of 1-3%wt for the Ss and about 35%wt for the X-zeolites, were tested against and . Redox activity was studied in physiological (pH 7.4/37 °C) and optimal (pH 8.5/37 °C) conditions in chemiluminescent model systems. In the ecotoxicity tests, we used Results: A proportional correlation was observed between the bactericidal effect of and the silver content in the zeolites. AgX with a Si/Al ratio of ~1.23 and 35% silver showed a higher antimicrobial efficiency, particularly against Gram-negative versus Gram-positive . The concentration thresholds were as follows: AgXas had a bactericidal effect at 0.003 g/L, with an MIC at 0.0015 m/L for ; SA25-Ag, AgXcl, AgXrc had a bactericidal effect at 2.5 g/L. The bacteria were more resilient than , which showed a 90-100% lethality at Ag-zeolite concentrations of 0.00625 to 0.0125 g/L. AgXas and AgXrc demonstrated strong reactive oxygen species generation at both the physiological and optimal pH, explaining their bactericidal effects. In general, the tested materials showed an inhibition of the generated reactive oxygen species depending on the model system and conditions.
The silver species leached from the new materials explain their higher oxidation and bactericidal activity. While suitable for stringently controlled biological applications, their release into the environment, in concentrations higher than 0.01g/L, should be avoided.
研究合成的载银沸石（X型和ZSM-5（MFI），硅铝比分别为12和25）的抗菌、氧化活性及生态毒性，将抗菌性能与材料结构和释放的活性银物种联系起来。
通过扫描电子显微镜（SEM）、能量散射X射线光谱（EDX）、透射电子显微镜（TEM）和X射线粉末衍射（XRPD）对材料进行表征。所有材料，Ss的银含量为1-3%wt，X型沸石的银含量约为35%wt，均针对[此处原文缺失具体受试对象]进行测试。在化学发光模型系统中，于生理条件（pH 7.4/37°C）和最佳条件（pH 8.5/37°C）下研究氧化还原活性。在生态毒性测试中，我们使用了[此处原文缺失具体受试对象]。结果：观察到[此处原文缺失具体受试对象]的杀菌效果与沸石中的银含量之间存在比例相关性。硅铝比约为1.23且银含量为35%的AgX表现出更高的抗菌效率，尤其对革兰氏阴性菌[此处原文缺失具体受试对象]相对于革兰氏阳性菌[此处原文缺失具体受试对象]。浓度阈值如下：AgXas在0.003 g/L时具有杀菌效果，对[此处原文缺失具体受试对象]的最低抑菌浓度（MIC）为0.0015 m/L；SA25-Ag、AgXcl、AgXrc在2.5 g/L时具有杀菌效果。细菌比[此处原文缺失具体受试对象]更具抗性，在载银沸石浓度为0.00625至0.0125 g/L时，[此处原文缺失具体受试对象]显示出90-100%的致死率。AgXas和AgXrc在生理和最佳pH条件下均表现出强烈的活性氧生成，这解释了它们的杀菌效果。总体而言，根据模型系统和条件，测试材料对生成的活性氧表现出抑制作用。
从新材料中浸出的银物种解释了它们较高的氧化和杀菌活性。虽然适用于严格控制的生物应用，但应避免其以高于0.01g/L的浓度释放到环境中。
