载银海藻酸钙纤维的制备及其应用性能

以海藻酸钙纤维和纳米银溶液为原料,采用浸渍富集法制备了载银海藻酸钙纤维。采用红外光谱(FTIR)和扫描电镜(SEM)表征了载银海藻酸钙纤维的结构,测试了载银前后海藻酸钙纤维的吸湿性能和力学性能,检测了不同银含量载银海藻酸钙纤维的抗菌性能。结果表明,载银海藻酸钙纤维表面的银颗粒粒径在20~50 nm左右,载银对海藻酸钙纤维的吸湿性能和力学性能影响较小,当载银海藻酸纤维银含量达到18 000mg/kg时,对白色念珠菌(ATCC 10231)、大肠杆菌(ATCC 25922)的抑菌率均达到99%以上。     

医用载银粘胶纤维的制备及其抗菌性能

采用耐尔(纳米银溶液浸渍法制备医用载银粘胶纤维。讨论了在固定浴比下,纳米银溶液浓度、浸渍温度和浸渍时间对载银粘胶纤维银含量的影响;测定了不同银含量的载银粘胶纤维的抗菌性能。结果表明:在固定浴比下,提高纳米银溶液浓度、提高浸渍温度和延长浸渍时间,可提高载银粘胶纤维的银含量。当载银粘胶纤维上的银含量达到100 mg/kg时,对大肠埃希菌(大肠杆菌)和金黄色葡萄球菌的抗菌率能达到99%以上;当载银粘胶纤维上的银含量达到500 mg/kg时,对白念珠菌的抗菌率能达到99%以上。     

载银海藻酸钙纤维水刺非织造布的制备及其抗菌性能

利用氨基纳米银溶液对海藻酸钙纤维水刺非织造布进行浸渍处理,制备载银海藻酸钙纤维水刺非织造布,对浸渍处理前后的表面形貌、成分、载银量、吸液性能和抗菌性能进行测试分析。结果表明,海藻酸钙纤维水刺非织造布能吸附氨基纳米银溶液中的银颗粒且银颗粒均匀地分布在海藻酸钙纤维表面;载银海藻酸钙纤维水刺非织造布的吸液率最高可达到20.590 g/g,对金黄色葡萄球菌和大肠埃希氏菌的抗菌率均达到99.00%以上。     

载银活性炭纤维的结构表征与抗菌性能研究

本文采用扫描电镜、X射线衍射和光电子能谱等手段对载银活性炭纤维的表面结构进行了表征和分析,并测试了其抗菌性能。结果表明:载银活性炭纤维表面银颗粒呈纳米级均匀分布,粒径为20~40 nm,其存在形式为单质银;载银活性炭纤维具有优异的抑菌性能,当银含量达到2 200 mg/kg时,对白色念珠菌(C.albicans)、大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)的抑菌率均可达到99.99%;载银活性炭纤维不仅起到抑制细菌生长繁殖的作用,还起到了一定程度的杀菌作用。     

载银活性炭纤维的制备及应用性能

以粘胶纤维、烷基化环糊精和硝酸银为原料,采用原位还原法制备载银粘胶纤维,再经炭化、活化制备了银含量约为2 200 mg/kg的载银活性炭纤维。结果表明,该载银活性炭纤维具有优异的抗菌性能,对白念珠菌（ATCC10231）、金黄葡萄球菌（ATCC6538）的抗菌率达到99%以上;具有优异的抗菌耐久性能,超声波清洗50次后,载银活性炭纤维的银含量未见明显下降;体外细胞毒性检测结果表明,载银活性炭纤维体外细胞毒性为1级,无明显的细胞毒性,体现了优异的生物安全性能。     

天然羊革载银工艺及其抗菌性能研究

采用纳米银对天然羊革进行抗菌改性处理,利用可见分光光度计快速测定纳米银溶液浓度,研究天然羊革的载银工艺,讨论了纳米银溶液浓度、浸渍温度和浸渍时间对天然羊革载银量的影响,探索纳米银对天然皮革的抗菌整理工艺并测试改性后天然羊革的抗菌性能。结果表明,当浴比1∶50,纳米银溶液浓度为5~35 mg/L,温度90℃,150 r/min振荡处理60 min,可制得银含量为350~1000 mg/kg的载银天然羊革,该载银天然羊革对金黄色葡萄球菌和大肠杆菌的抑菌率超过9%,并具有优良的抗菌耐洗性,洗涤10次后其抑菌率仍超过90%。     

棉纤维载银处理对其服用性能与抗菌性能的影响

探讨了棉纤维载银处理后的服用与抗菌性能。研究表明,棉纤维的载银量、纤维表面摩擦系数随着纳米银溶液质量浓度的增加而增加,而纤维的吸湿回潮率、力学性能则随着纳米银溶液质量浓度的增加而降低,当纳米银溶液质量浓度超过100 mg/L时,变化速率减小。当纳米银溶液质量浓度为30 mg/L时,棉纤维的载银量已达620.7 mg/kg,能够满足白念珠菌、革兰氏阳性菌金黄色葡萄球菌、革兰氏阴性菌大肠埃希菌载银量600、200与100 mg/kg的抗菌要求。认为:棉纤维纳米银溶液质量浓度为30 mg/L时进行载银处理,不仅保留了棉纤维较好的服用性能,也使得棉纤维具有较好的医用抗菌性能。     

羟基功能化纳米银的制备及性能

通过一步法合成了端羟基超支化聚(胺-酯)(HBP-OH),并利用其制备了一种高亲和性非离子体系的羟基功能化纳米银。利用UV-Vis、DLS、TEM对所制备的纳米银进行了表征,并测试了羟基功能化纳米银的抗菌性能。研究表明,利用HBP-OH制备的纳米银溶液具有良好的分散性和均匀性,纳米银颗粒的平均粒径约为15 nm;羟基功能化纳米银颗粒的Zeta电位随p H的变化趋势符合非离子体系纳米银颗粒Zeta电位的变化规律;纳米银对E.coli和S.aureus均具有优异的抗菌性能,且最小抑菌质量浓度约为4 mg/L。     

芦荟纳米银的制备及其对真丝织物的抗菌整理

利用芦荟液在酸性环境和碱性环境下制备纳米银,酸性环境下制得的银粒子平均粒径最小在10 am以内.采用芦荟纳米银溶液对桑蚕丝织物进行了功能性整理,并研究了织物的抗菌性能和耐洗性能.研究结果表明:整理后的桑蚕丝织物抑菌率可达99.9%,织物上银含量为107.35 mg/kg时,抑菌率也达到了99.8%,耐洗性能良好.     

纳米银的制备及其对涤纶织物抗菌整理

为了实现涤纶织物的抗菌功能化改性目标,本文以自制的端氨基超支化聚合物（HBP-NH2）为还原剂制备纳米银,利用制得的纳米银溶液对涤纶织物进行抗菌整理,采用扫描电镜观察抗菌织物的纤维表面形态;测定了整理织物的抗菌效率、白度及耐洗性。试验结果表明,制得的纳米银平均粒径在20nm以内,稳定性能良好。当织物上银含量为125.412mg/kg时,对金黄色葡萄球菌和大肠杆菌的抑菌率分别达99.42%和99.27%;洗涤50次后,对金黄色葡萄球菌和大肠杆菌的抑菌率仍保持在98.32%以上,整理效果的耐洗性较好。     

基于共价结合的纳米银抗菌棉织物研究进展

针对棉织物与纳米银之间缺乏亲和性,主要依靠物理吸附结合,水洗牢度差等问题,总结了基于共价结合的纳米银抗菌棉织物的最新研究进展,探讨了席夫碱反应和酯化反应这2种共价结合机制。以纳米银与棉织物之间的共价交联剂(超支化聚合物、树状大分子、丝素、丝胶、半胱氨酸、蛋氨酸、巯基乙酸、壳聚糖衍生物、聚苯乙烯-b-聚丙烯酸、丁烷四羧酸)种类进行分类介绍,结合抑菌率和银含量的数据讨论了基于共价结合的纳米银抗菌棉织物的制备工艺、抗菌性能和抗菌耐洗性能。最后对基于共价结合的纳米银抗菌棉织物领域存在的不足和未来需要深入关注的地方进行了探讨。研究指出,共价交联法大幅提高了纳米银的抗菌耐洗性能,为开发环境友好和长效抗菌的纳米银纺织品提供了新思路和新途径。     

Fabrication of Novel Antimicrobial Bio-Fibers Using Silk Wastage,Study of Poly (hexamethylene) Biguanide,and Silver Nanoparticles Interaction

Regenerated silk fibers were fabricated through dry-wet spinning process using N-methyl morpholine N-oxide and methanol as solvent and coagulant, respectively. Several concentrations of poly (hexamethylene) biguanide (PHMB) (0.27, 0.41, and 0.55 mL per 1 g of fibroin) and silver nanoparticles (AgNPs) (0.0005, 0.0015, 0.0055, 0.0095, and 0.0135% (w/v) were used as antibacterial agents. Antibacterial property of bio-fibers produced by either master batch or dipping methods was compared to each other against a gram-positive bacterium, Staphylococcus aurous. Master batch process indicated the dependency of antibacterial effect on the concentration of antibacterial agents as well as particle size. Maximum bactericidal activity in this process was obtained at concentrations of 0.0055% of AgNPs and 0.55 mL of PHMB per 1 g of fibroin. However for long-lasting effect and from toxicity aspect PHMB with lower concentration (0.27 mL) and with 0.0055% AgNP was seemed to be ideal. The result from dipping process showed that various concentrations of PHMB can greatly influence on the results; the interaction of 0.0055% AgNPs and 0.41 mL of PHMB offered good antibacterial properties with the least amount of toxicity effect in human cells.     

Silver nanoparticles: A novel antibacterial agent for control of Cronobacter sakazakii

Silver nanoparticles (AgNP) have been widely applied because of their broad spectrum of antimicrobial activities against bacteria, fungi, and viruses. However, little research has been done to evaluate their effects on Cronobacter sakazakii, an opportunistic pathogen usually infecting infants and having a high fatality rate. The aims of this work were to investigate the antibacterial property of novel, synthesized, positively charged silver nanoparticles against C. sakazakii and to discuss the potential antibacterial mechanisms involved. In this study, the spherical and face-centered cubic silver nanoparticles had a mean particle size of 31.2 nm and were synthesized by reducing Ag⁺ using citrate and dispersed by glycerol and polyvinylpyrrolidone (PVP) under alkaline conditions. Minimum inhibitory concentrations (MIC) and inhibition zone tests showed that the AgNP exhibited strong antibacterial activity against 4 tested C. sakazakii strains with mean MIC of 62.5 to 125 mg/L and average inhibition zone diameters of 13.8 to 16.3 mm. Silver nanoparticles caused cell membrane injury accompanied by adsorption of AgNP onto the cell surface, as shown by changes in cell morphology, cell membrane hyperpolarization, and accelerated leakage of intracellular reducing sugars and proteins outward from the cytoplasm. In addition, dysfunction of the respiratory chain was induced after treatment with AgNP, which was supported by a decrease in intracellular ATP and inhibition of related dehydrogenases. This research indicates that AgNP could be a novel and efficient antibacterial agent to control C. sakazakii contamination in environments producing powdered infant formulas from milk.     

负载小麦醇溶蛋白纳米银胶体颗粒的抗菌壳聚糖复合膜构建及表征

本研究采用浇筑法,成功构建了Ag NPs/小麦醇溶蛋白/壳聚糖复合抑菌膜,实现了Ag NPs的稳态化和协同增效。自组装的小麦醇溶蛋白(gliadin),同时充当AgNPs的螯合剂和稳定剂,有效抑制了纳米银颗粒(AgNPs)团聚。与其他复合膜相比,gliadin/Ag NPs复合膜透明度良好。SEM和EDS证实Ag NPs均匀分布于复合膜。此外,gliadin/AgNPs复合颗粒具有优异的缓释特性。人皮肤成纤维细胞评估结果表明复合膜具有更好的生物相容性,激光共聚焦显微镜(CLSM)显示gliadin/Ag NPs复合膜对大肠杆菌与金黄色葡萄球菌具有更强的抗菌效果。这些薄膜在抗菌食品包装材料、伤口敷料以及植入物的开发方面极具应用价值。     

More than the ions: the effects of silver nanoparticles on Lolium multiflorum

Silver nanoparticles (AgNPs) are increasingly used as antimicrobial additives in consumer products and may have adverse impacts on organisms when they inadvertently enter ecosystems. This study investigated the uptake and toxicity of AgNPs to the common grass, Lolium multiflorum. We found that root and shoot Ag content increased with increasing AgNP exposures. AgNPs inhibited seedling growth. While exposed to 40 mg L(-1) GA-coated AgNPs, seedlings failed to develop root hairs, had highly vacuolated and collapsed cortical cells and broken epidermis and rootcap. In contrast, seedlings exposed to identical concentrations of AgNO(3) or supernatants of ultracentrifuged AgNP solutions showed no such abnormalities. AgNP toxicity was influenced by total NP surface area with smaller AgNPs (6 nm) more strongly affecting growth than did similar concentrations of larger (25 nm) NPs for a given mass. Cysteine (which binds Ag(+)) mitigated the effects of AgNO(3) but did not reduce the toxicity of AgNP treatments. X-ray spectro-microscopy documented silver speciation within exposed roots and suggested that silver is oxidized within plant tissues. Collectively, this study suggests that growth inhibition and cell damage can be directly attributed either to the nanoparticles themselves or to the ability of AgNPs to deliver dissolved Ag to critical biotic receptors.     

MHBP-OH纳米银的制备及其对棉织物的长效抗菌整理

为了有效控制制备纳米银,本文对端氨基超支化聚合物(HBP-NH2)进行了接枝改性,制备了"核-壳"结构的改性超支化聚合物(MHBP-OH)。利用其在水溶液中制备了纳米银,并将其接枝到棉织物中原位控制生成纳米银,以实现对棉织物的抗菌整理。对生成的纳米银进行了表征,并对原位生成纳米银整理的棉织物进行了测试。结果表明:水溶液中控制生成的纳米银平均粒径为3.82 nm,并具有优异的稳定性,棉织物中原位生成的纳米银粒径在10 nm左右,在棉纤维上分布均匀,当银含量为146.26 mg/kg时,整理后的棉织物对金黄色葡萄球菌和大肠杆菌的抑菌率分别达到99.76%和99.62%,30次洗涤后,银含量仍保持在126.61 mg/kg。     

甲壳胺纤维抗菌试验性方法及影响因素的初步研究

以金黄色葡萄球菌为实验菌种，从实验角度证实甲壳胺纤维的抗菌为接触性抑菌；并利用烧瓶振荡法，探讨了试验条件如pH值、温度对甲壳胺纤维抑菌率的影响。研究表明，甲壳胺纤维对金黄色葡萄球菌的抑菌率随pH值的下降而增强，而温度对其抗菌性影响则不明显。     

Differential effect of common ligands and molecular oxygen on antimicrobial activity of silver nanoparticles versus silver ions

The antibacterial activity of silver nanoparticles (AgNPs) is partially due to the release of Ag(+), although discerning the contribution of AgNPs vs Ag(+) is challenging due to their common co-occurrence. We discerned the toxicity of Ag(+) versus a commercially available AgNP (35.4 ± 5.1 nm, coated with amorphous carbon) by conducting antibacterial assays under anaerobic conditions that preclude Ag? oxidation, which is a prerequisite for Ag(+) release. These AgNPs were 20× less toxic to E. coli than Ag(+) (EC??: 2.04 ± 0.07 vs 0.10 ± 0.01 mg/L), and their toxicity increased 2.3-fold after exposure to air for 0.5 h (EC??: 0.87 ± 0.03 mg/L) which promoted Ag(+) release. No significant difference in Ag(+) toxicity was observed between anaerobic and aerobic conditions, which rules out oxidative stress by ROS as an important antibacterial mechanism for Ag(+). The toxicity of Ag(+) (2.94 μmol/L) was eliminated by equivalent cysteine or sulfide; the latter exceeded the solubility product equilibrium constant (K(sp)), which is conducive to silver precipitation. Equivalent chloride and phosphate concentrations also reduced Ag(+) toxicity without exceeding K(sp). Thus, some common ligands can hinder the bioavailability and mitigate the toxicity of Ag(+) at relatively low concentrations that do not induce silver precipitation. Furthermore, low concentrations of chloride (0.1 mg/L) mitigated the toxicity of Ag(+) but not that of AgNPs, suggesting that previous reports of higher AgNPs toxicity than their equivalent Ag(+) concentration might be due to the presence of common ligands that preferentially decrease the bioavailability and toxicity of Ag(+). Overall, these results show that the presence of O? or common ligands can differentially affect the toxicity of AgNPs vs Ag(+), and underscore the importance of water chemistry in the mode of action of AgNPs.     

溶胶-凝胶法制备氮掺杂纳米ZnO及其抗菌性能研究

以硝酸锌为锌源,氨水为沉淀剂,壳聚糖为添加剂,通过溶胶-凝胶法制备出粒度小、形貌分布均匀、氮掺杂量高的肤色氮掺杂纳米ZnO晶体,研究了壳聚糖对产品微观结构及性能的影响.采用SEM、TEM、XRD和IR等手段对产品微观结构进行了表征,对其抗菌性能进行了评价.结果表明:添加壳聚糖有利于凝胶的快速形成,而且可通过壳聚糖的添加量有效控制纳米晶体的大小、形貌以及氮掺杂量,最终得到平均粒径为30 nm的球形氮掺杂纳米ZnO晶体,晶相与标准立方相ZnO衍射峰完全一致,没有其他杂相出现,颜色为均匀的红色.和普通的纳米ZnO晶体相比,抑菌结果显示合成的氮掺杂纳米ZnO晶体对大肠杆菌具有优良的抗菌性.     

壳聚糖接枝共聚制备抗菌性竹浆粕

为了赋予竹纤维抗菌性,以天然生物高分子壳聚糖为抗菌整理剂,利用K2S2O8与Na2S2O3组成的氧化还原体系,引发竹纤维素与壳聚糖进行接枝共聚,制备了具有抗菌性的纤维素材料.以接枝率和接枝效率作为衡量标准,确定了最佳反应条件,并对在最佳条件下合成的样品进行了红外、扫描电镜和抗菌性检测.研究结果表明,竹纤维素与壳聚糖接枝共聚后,纤维表面形态明显改变,对大肠杆菌和金黄色葡萄球菌的抑菌率分别达到97.00％和99.91％,具有良好的抗菌性.