Silver nanoparticles (Ag NPs) can effectively address the issue of antibiotic-resistant bacterial infections to reduce the potential toxicity of Ag NPs. Although challenging, it is, therefore, necessary to achieve the...Silver nanoparticles (Ag NPs) can effectively address the issue of antibiotic-resistant bacterial infections to reduce the potential toxicity of Ag NPs. Although challenging, it is, therefore, necessary to achieve the sustainable release of Ag+ ions from a finite amount of Ag NPs. This study aims at designing an efficient and benign antimicrobial silver-based ternary composite composed of photocatalysis zinc oxide (ZnO) and reduced graphene oxide (rGO) as a carrier, in which the reactive oxygen species (ROS) excited from ZnO and Ag+ ions released from the Ag NPs cooperate to realize an effective antibacterial activity against E. coli and S. aureus. The constant effective bacterial performance of the ternary photocatalyst with minimum Ag content can be attributed to the increase in the available quantity of ROS, which results from the enhanced separation efficiency of the photogenerated carriers. The proposed system notably realized the long-term sustainable release of Ag+ ions with low concentration for 30 days when compared with an equivalent amount of silver nitrate. Moreover, the use of the composite prevents biotoxicity and silver wastage, and imparts enhanced stability to the long-lasting antibacterial efficacy.展开更多
In the present study,the distribution of Ag in the coating formed on Mg-Ag alloy by plasma electrolytic oxidation(PEO)and its ionic release kinetics when exposed to a 0.9 wt.%Na Cl solution at 37℃have been investigat...In the present study,the distribution of Ag in the coating formed on Mg-Ag alloy by plasma electrolytic oxidation(PEO)and its ionic release kinetics when exposed to a 0.9 wt.%Na Cl solution at 37℃have been investigated.Both metallic Ag and Ag oxide particles with~5 to~40 nm in diameters were observed in the PEO coating.Further,an Ag-enriched layer of~20 nm in thickness at the substrate/coating interface was also observed.The PEO coating on the Mg-Ag alloy not only increases its corrosion resistance with the corrosion current density decreasing by up to 3 orders of magnitude from 8.04×10^(-3)to 4.03×10^(-6)A/cm^(2),but also controls the release of Ag+to the level that is sufficient for anti-infective efficacy without causing cytotoxicity to mammal cells.展开更多
目的:建立含银敷料的表征和银体外释放及鉴别释放液中纳米银和银离子的实验方法;探讨其在相关产品检测中的应用。方法:通过扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)、X射线光电子能谱仪(XPS)对含银敷料进行形貌及银颗粒价态分析表...目的:建立含银敷料的表征和银体外释放及鉴别释放液中纳米银和银离子的实验方法;探讨其在相关产品检测中的应用。方法:通过扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)、X射线光电子能谱仪(XPS)对含银敷料进行形貌及银颗粒价态分析表征;采用摇床法及往复支架法考察含银敷料在纯水和模拟体液(SBF)中的释放特性。通过体外细胞毒性研究,讨论材料表征与细胞毒性风险评价的相关性。结果:通过使用10 k D滤膜的超滤管实现了纳米银颗粒的有效分离,并通过调整释放液中氯离子/银离子的浓度比排除了SBF释放液中可能存在的氯化银颗粒物的干扰。利用所建立的规范性试验方法对实验所用的2种含银敷料进行了评价。其结果显示2种含银敷料均含纳米银,往复支架法体外释放试验显示含银烧烫伤贴24 h内在纯水和SBF中释放总银分别为5.24、12.41μg·cm-2,表明在SBF中的总银释放量高于纯水中释放量(约2倍);且SBF中银颗粒的释放比例略高于纯水中的释放比例。细胞毒性评价(MTT、LDH)的结果显示含银烧烫伤贴细胞毒性大于含银创伤贴,与总银释放量呈正相关。结论:本课题建立的含银敷料表征和银释放特性的实验方法,能够有效地判定敷料中是否含有纳米银及是否有纳米银颗粒的释放,为正确地对含银敷料进行风险评估及合理有效的监管提供科学依据。展开更多
基金supported by the National Natural Science Foundation of China(51472101,51572114,21773062,21577036)the Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials(JSKC17003)~~
文摘Silver nanoparticles (Ag NPs) can effectively address the issue of antibiotic-resistant bacterial infections to reduce the potential toxicity of Ag NPs. Although challenging, it is, therefore, necessary to achieve the sustainable release of Ag+ ions from a finite amount of Ag NPs. This study aims at designing an efficient and benign antimicrobial silver-based ternary composite composed of photocatalysis zinc oxide (ZnO) and reduced graphene oxide (rGO) as a carrier, in which the reactive oxygen species (ROS) excited from ZnO and Ag+ ions released from the Ag NPs cooperate to realize an effective antibacterial activity against E. coli and S. aureus. The constant effective bacterial performance of the ternary photocatalyst with minimum Ag content can be attributed to the increase in the available quantity of ROS, which results from the enhanced separation efficiency of the photogenerated carriers. The proposed system notably realized the long-term sustainable release of Ag+ ions with low concentration for 30 days when compared with an equivalent amount of silver nitrate. Moreover, the use of the composite prevents biotoxicity and silver wastage, and imparts enhanced stability to the long-lasting antibacterial efficacy.
基金the financial support from the Hubei Provincial Natural Science Foundation of China(No.2020CFB295)the National Natural Science Foundation of China(No.52001128)+1 种基金the Innovative Foundation of Huazhong University of Science and Technology(No.2021JYCXJJ023)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(No.B21003)。
文摘In the present study,the distribution of Ag in the coating formed on Mg-Ag alloy by plasma electrolytic oxidation(PEO)and its ionic release kinetics when exposed to a 0.9 wt.%Na Cl solution at 37℃have been investigated.Both metallic Ag and Ag oxide particles with~5 to~40 nm in diameters were observed in the PEO coating.Further,an Ag-enriched layer of~20 nm in thickness at the substrate/coating interface was also observed.The PEO coating on the Mg-Ag alloy not only increases its corrosion resistance with the corrosion current density decreasing by up to 3 orders of magnitude from 8.04×10^(-3)to 4.03×10^(-6)A/cm^(2),but also controls the release of Ag+to the level that is sufficient for anti-infective efficacy without causing cytotoxicity to mammal cells.
文摘目的:建立含银敷料的表征和银体外释放及鉴别释放液中纳米银和银离子的实验方法;探讨其在相关产品检测中的应用。方法:通过扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)、X射线光电子能谱仪(XPS)对含银敷料进行形貌及银颗粒价态分析表征;采用摇床法及往复支架法考察含银敷料在纯水和模拟体液(SBF)中的释放特性。通过体外细胞毒性研究,讨论材料表征与细胞毒性风险评价的相关性。结果:通过使用10 k D滤膜的超滤管实现了纳米银颗粒的有效分离,并通过调整释放液中氯离子/银离子的浓度比排除了SBF释放液中可能存在的氯化银颗粒物的干扰。利用所建立的规范性试验方法对实验所用的2种含银敷料进行了评价。其结果显示2种含银敷料均含纳米银,往复支架法体外释放试验显示含银烧烫伤贴24 h内在纯水和SBF中释放总银分别为5.24、12.41μg·cm-2,表明在SBF中的总银释放量高于纯水中释放量(约2倍);且SBF中银颗粒的释放比例略高于纯水中的释放比例。细胞毒性评价(MTT、LDH)的结果显示含银烧烫伤贴细胞毒性大于含银创伤贴,与总银释放量呈正相关。结论:本课题建立的含银敷料表征和银释放特性的实验方法,能够有效地判定敷料中是否含有纳米银及是否有纳米银颗粒的释放,为正确地对含银敷料进行风险评估及合理有效的监管提供科学依据。
