Influence of Composite Phosphate Inorganic Antibacterial Materials Containing Rare Earth on Activated Water Property of Ceramics

Antibacterial ceramic was prepared by doping enamel slurry with composite phosphate inorganic antibacterial materials containing rare earth (inorganic antibacterial additives), and then the mechanisms for activating water and improving seed germinative property were tested by nuclear magnetic resonance (NMR) and the method of testing oxygen dissolved in activated water. Results show that the half peak width of (()^(17)O-NMR) for tap water activated by the antibacterial ceramic drops from 115.36 to 99.15 Hz, and oxygen concentrations of activated water increase by 20%, germinate rate of horsebean and earthnut seeds increases by 12.5% and 7.5%, respectively. Therefore antibacterial ceramic doped enamel slurry with inorganic antibacterial additives containing rare earth can reduce the volume of clusters of water molecules, improve activation of tap water, and promote plant seeds germinate.

Silver Supported on White Carbon Black Containing Rare Earths as Antibacterial Material

The antimicrobial effect of the Ag-White Carbon Black containing rare earth was investigated. Inorganic antibiotic materials consist of the antibacterial ion, the additive and the carrier. The sol-gel method was used to prepare the white carbon black carrier. Ag+ was selected to be the antibacterial ion, and cerous nitrate was selected to be the additive. They were synthesized on the white carbon black carrier. The structures and properties of antibacterial material were characterized by inductively coupled plasma, particle size measurement instrument, fourier transform infrared and enumeration tests (Escherichia coli as experimental bacterium). Results showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the general Ag-antibacterial white carbon black (without containing rare earth). Ag+ was bound to white carbon black by ion exchange process and adsorption process. Bacteriostasis rate is over 99%, and the particle size can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are good thermal and light stability. Furthermore, from the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.

Preparation and Characterization of Cu-Ag-inorganic Antibacterial Material Containing Rare Earths

Inorganic antibacterial materials consist of the antibacterial ions, the additives and the carrier. In this study, we synthesized a new inorganic antibacterialmaterial, of which Cu2+ and Ag+ were selected to be the bi-component antibacterial ions, cerous nitrate served as the additives, and the white carbon black was chosen as the carrier, which was prepared by a sol-gel method. The as-synthesized antibacterial material was characterized by inductively coupled plasma, particle size measurement instrument, scanning electron microscope and enumeration tests. The result showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the single-ion inorganic antibacterial material. In addition, the particle size of this material can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are its loose and dispersive structure, good thermal and light stability. From the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.

Preparation and Application of Active Composite Antibacterial Material Containing Ag^+ and Zn^(2+)

A kind of active composite antibacterial material was prepared with CaHPO4 as the container, Ag^＋ and Zn^2＋ were adsorbed through ion-exchange, then it was doped with small scale of rare earth and photocatalyst, and was finally calcined at a certain temperature. The properties and application of the composite material antibacterial were investigated. Some tests show that the as-prepared antibacterial powders modified by opaque agents such os SnO2 and ZrO2, possess beautiful white and excellent climate resistance at normal temperatures and are promising candidate materials for antibacterial plastics and dope. The result of the application in glaze indicates that Ag^＋ can still exist stably, with no color change for the glaze, even being sintered at 1200℃ . SEM , EDS , antibacterial activity analyses and contrast tests reveal that the as-prepared antibacterial powders and the antibacterial glaze both have excellent antibacterial activities, without color change, in the case of dark or brightness.

Thermal stability and long-acting antibacterial activity of phosphonium montmorillonites

Na-montruorillonite （Na-MMT） was exchanged with three quaternary atkylphosphonium salts： decyl tributylphosphonium bromide （DTBPBr）, dodecyl tributylphosphonium bromide （DDTBPBr） and hexadecyl tributylphosphonium bromide （HDTBPBr）, to investigate the effects of phosphonium salts species and relative molecular mass on the characteristics, morphology, thermal stability and long-acting antibacterial property of phosphonium montmorillonites. The resulting modified montmorillonites were characterized by the FTIR, XRD, TEM, and TG/DTG techniques. And minimum inhibitory concentration （MIC） was used to investigate antibacterial activity. The results show that the phosphonium salts are intercalated into Na-MMT, and the basal spacing of P-MMTs is enlarged with the increase of phosphonium salt content or the growth of alkyl chain length. DDTBP-MMT-3 with 19.83% （mass fraction of dodecyl tributylphosphonium salts, displays excellent thermal stability and long-acting antibacterial activity.

The Antibacterial Effect of Silver-carrying B_2O_3-SiO_2-Na_2O Glass Material

The antibacterial effect of carrying silver B_2O_3-SiO_2-Na_2O glass material was studied by means of antibacterial ring, nephelometery,MIC value, thin film attachment and microcalorimetry, respectively. The experimental results of five kinds of antibacterial test methods are almost identical and can verify that carrying silver B_2O_3-SiO_2-Na_2O glass material exerts an excellent antibacterial performance. Antibacterial ring and nephelometery are simple, quick, but the precision is restrictive. MIC value, thin film attachment method and microcalorimetry can quantitatively compare the antibacterial effects of the antibacterial glass material.Compared with the traditional microbe test methods, the microcalorimetry can analyze the inhibiting effect of the cell's growth and metabolism on the antibacterial glass material by monitoring the thermal effect continuously and automatically.

Evaluation of Antibacterial Effect by Using a Fibrous Grafted Material Loaded Ag Ligand

To obtain the safety of drinking water, an antibacterial material was prepared by loading silver (Ag) onto fibrous iminodiacetate (IDA) adsorbent, which was synthesized by radiation-induced graft polymerization of glycidyl methacrylate and subsequent chemical modification of the produced epoxy group to an IDA group (IDA-Ag). A total amount of loaded Ag on the IDA-Ag fabric was 0.4 mmol-Ag/g-fabric. From an observation of the IDA-Ag fabric cross section by a scanning electron microscope energy dispersive X-ray spectrometer, Ag was distributed to IDA layer uniformly. As a result of evaluating antibacterial effects by the column mode water flow test with stream water, the effective Ag concentration was monitored 0.05 ppm at irrespective flow rate which was functioned to the antibacterial performance. The antibacterial effects for general bacteria were indicated until BV (BV: steam water volume/IDA-Ag fabric volume) 6000, and for colitis germ legions were completely disinfected until BV 6000.

Antibacterial mechanism with consequent cytotoxicity of different reinforcements in biodegradable magnesium and zinc alloys: A review

Benefits achieved by the biodegradable magnesium(Mg) and zinc(Zn) implants could be suppressed due to the invasion of infectious microbial, common bacteria, and fungi. Postoperative medications and the antibacterial properties of pure Mg and Zn are insufficient against biofilm and antibiotic-resistant bacteria, bringing osteomyelitis, necrosis, and even death. This study evaluates the antibacterial performance of biodegradable Mg and Zn alloys of different reinforcements, including silver(Ag), copper(Cu), lithium(Li), and gallium(Ga). Copper ions(Cu^(2+)) can eradicate biofilms and antibiotic-resistant bacteria by extracting electrons from the cellular structure. Silver ion(Ag^(+)) kills bacteria by creating bonds with the thiol group. Gallium ion(Ga^(3+)) inhibits ferric ion(Fe^(3+)) absorption, leading to nutrient deficiency and bacterial death. Nanoparticles and reactive oxygen species(ROS) can penetrate bacteria cell walls directly, develop bonds with receptors, and damage nucleotides. Antibacterial action depends on the alkali nature of metal ions and their degradation rate, which often causes cytotoxicity in living cells. Therefore, this review emphasizes the insight into degradation rate, antibacterial mechanism, and their consequent cytotoxicity and observes the correlation between antibacterial performance and oxidation number of metal ions.

Biological oyster shell waste enhances polyphenylene sulfide composites and endows them with antibacterial properties

To date,there is no research that deals with biological waste as fillers in polyphenylene sulfide(PPS).In this study,oyster shells were recycled and treated to prepare thermally-treated oyster shells(TOS),which were used as PPS fillers to make new bio-based antibacterial composite materials.The effect of varying the content of TOS was studied by means of structure and performance characterization.PPS/TOS composites were demonstrated to have an antibacterial effect on the growth of E coli and S.aureus.Qualitative analysis showed that when the TOS content was≥30%and 40%,the composite materials had an apparent inhibition zone.Quantitative analysis showed that the antibacterial activity increased with the TOS content.Fourier transform infrared spectroscopy indicated the formation of hydrogen bonds between the molecular chains of TOS and PPS and the occurrence of a coordination reaction.At 10%TOS,the composite tensile strength reached a maximum value of 72.5 MPa,which is 9.65%higher than that of pure PPS.The trend of bending properties is the same as that of tensile properties,showing that the maximum property was reached for the composite with 10%TOS.At the same time,the crystallinity and contact angle were the highest,and the permeability coefficient was the lowest.The fatigue test results indicated that for the composite with 10%TOS,the tensile strength was 23%lower than static tensile strength,and the yield strength was 10%lower than the static yield strength.The results of the study showed that TOS not only could reduce the cost of PPS,but also could impart antibacterial properties and enhance the mechanical and,barrier properties,the thermostability,as well as the crystallinity.

Chemical composition, mechanism of antibacterial action and antioxidant activity of leaf essential oil of Forsythia koreana deciduous shrub

Objective: To identify the chemical constituents of leaf essential oil of Forsythia koreana(F. koreana) and evaluate its ef ects on bacterial strains. Methods: The essential oil of leaf of F. koreana was extracted by using hydrodistillation process and the volatile components investigated with the help of gas chromatography coupled with mass spectrometry. The antibacterial study was carried out with the help of agar disc dif usion method, MIC, MBC and viable count. The mode of action was determined with help of potassium ion l ux, cellular material release and scanning electron microscopy. The antioxidant activity was determined with the help of 2, 3-diphenyl-2-picrylhydrazyl method, nitric oxide scavenging activity and superoxide anion radical scavenging assay. Results: Total ten compounds were identii ed as trans-phytol(42.73%), cis-3-hexenol(12.95%), 毬-linalool(10.68%), trans-2-hexenal(8.86%), trans-2-hexenol(8.86%), myrcenol(3.86%), 4-vinylphenyl acetate(3.86%),(4Z)-4,6-heptadien-1-ol(3.18%), lemonol(2.73%) and benzeneacetaldehyde(2.27%) by gas chromatography coupled with mass spectrometry. The antibacterial study was demonstrated that leaf essential oil of F. koreana act against foodborne and other pathogenic bacteria. The mode of action revealed that this essential oil acted on the cytoplasmic membrane, resulting in loss of integrity and increased permeability. In addition, leaf essential oil of F. koreana was shown to be rich in linalool, which contributes to improved antioxidant activity. Conclusions: These results show that leaf essential oil of F. koreana has great potential as a natural food preservative, antibacterial and antioxidant agent.

The Self-assembling and Application of Inorganic Anti-bacterial Material Made of Natural Nanoporous Carrier

The inorganic antimicrobial material was inhibited to the microbes with the added metal ion,Zn.The primary wet product carrying 5%-10% zinc ion was generated under the following conditions：temperature was 95 ℃,solution zinc concentration was 1.2-2.0 mol/L,and the ratio of Zn solution to zeolite weight was 5：1.The final stable product was manufactured after baking in an oven for 1-3 h at the temperature of 500-900 ℃.The baked material was tested for its disinfection effectiveness and coloring effect when mixed with paint coating.Based on the final batch of tests,the zinc content of this anti-microbial product was further optimized.

A novel biodegradable Mg-1Zn-0.5Sn alloy:Mechanical properties,corrosion behavior,biocompatibility,and antibacterial activity

To meet the growing demand for antibacterial implants for bone-implant-associated infection therapy and avoid the adverse effects of secondary surgery,a degradable platform with pH responsiveness and ion-associated antibacterial properties was constructed.A small amount of Sn added to Mg-1Zn alloy reduces the biocorrosion rate,which can be attributed to Sn participation in outer-layer film formation,significantly reducing the biocorrosion rate and hydrogen evolution rate after implantation in vivo.These Mg alloys,which are susceptible to degradation in the acidic bacterial microenvironment,degrade by releasing Mg,Zn and Sn,producing favorably alkaline and antibacterial conditions.Samples with the composition of Mg-1Zn-0.5Sn were found to be beneficial for promoting initial cell adhesion and proliferation,resulting in improved biocompatibility and biosafety.The biocompatibility of this alloy was confirmed by the healthy behavior of animals and the absence of acute or chronic toxicity in the liver,spleen,and kidneys.Our results demonstrate that Mg-1Zn-0.5Sn is safe for biological systems,enabling its efficacious use in biomedical applications.

Prediction Model of Antibacterial Activities for Inorganic Antibacterial Agents Based on Artificial Neural Networks

Quantitatively evaluation of antibacterial activities of inorganic antibacterial agents is an urgent problem to be solved. Using experimental data by an orthogonal design, a prediction model of the relation between conditions of preparing inorganic antibacterial agents and their antibacterial activities has been developed. This is accomplished by introducing BP artificial neural networks in the study of inorganic antibacterial agents. It provides a theoretical support for the development and research on inorganic antibacterial agents. Key words inorganic antibacterial agent - antibacterial activity - neural networks - nanometer material

Preparation of Gallic Acid-chitosan Copolymer and Its Antibacterial Activity against Staphylococcus Aureus and Escherichia Coli

To synthesize three different grafting ratios of gallic acid(GA)-chitosan(CS)copolymer by a free radical mediated grafting method,which is further applied to the field of antibacterial materials,crosslinking structures of the compound GA-CS copolymer were characterized,fully indicating that gallic acid is resoundingly grafted onto chitosan.The grafting ratios of three copolymers GA-CS are 45.71%(Ⅰ),36.12%(Ⅱ),and 18.96%(Ⅲ)were determined by UV-Vis spectrophotometer.The minimum inhibitory concentrations of three GA-CS copolymers are 30μg/mL against Escherichia coli and are ranged from 250 to 550μg/mL against Staphylococcus aureus.By counting viable bacterial colonies,it can be found that antibacterial property is preferable by increasing the grafting ratio of GA-CS copolymers.Findings of investigation on aforementioned bacteria experiment indicate that the CFU/mL values of GA-CS(Ⅰ,Ⅱ,Ⅲ)are 2.04×10^(6),7.56×10^(6),1.48×10^(7) to Staphylococcus aureus,and 2.96×10^(6),1.01×10^(7),2.14×10^(7) to Escherichia coli after 12 h treatment.In addition,the interaction process between GA-CS copolymer and bacteria can be observed through a transmission electron microscope.The specific manifestation is that the bacterial cell membranes are ruptured after being treated with the copolymer,which causes the cell contents to flow out,and the cell morphology is shrunk and out ofshape.

Controllable NO Release for Catheter Antibacteria from Nitrite Electroreduction over the Cu-MOF

Implant-associated infections caused by biomedical catheters severely threaten patients'health.The use of electrochemical control on NO release from benign nitrite equipped in the catheter can potentially resolve this issue with excellent biocompatibility.Inspired by nitrite reductase,a Cu-BDC(BDC:benzene-1,4-dicarboxylic acid)catalyst with coordinated Cu(Ⅱ)sites was constructed as a heterogeneous electrocatalyst to control nitrite reduction to nitric oxide for catheter antibacteria.The combined results of in situ and ex situ tests unveil the key function of interconversion between Cu(Ⅱ)and Cu(Ⅰ)species in NO_(2)^(-)reduction to NO.After being incorporated into the actual catheter,the Cu-BDC catalyst exhibits high electrocatalytic activity toward NO_(2)^(-)reduction to NO and excellent antibacteria efficacy with a sterilizing rate of 99.9%,paving the way for the development of advanced metal-organic frameworks(MOFs)electrocatalysts for catheter antibacteria.

Preparation of Immobilized ε-Polylysine PET Nonwoven Fabrics and Antibacterial Activity Evaluation

A novel antibacterial material （L-PET） was prepared by immobilizing ε-polylysine on polyethylene terephthalate （PET） nonwoven fabrics. Surface modifications of the fabric were performed by using a chemical modification procedure where carboxyl groups were prepared on the PET surface, a coupling agent was grafted, and the ε-polylysine was immobilized. Scanning electron microscopy （SEM） was used to analyze the surface morphology of the fabrics, while the toluidine blue method and X-ray photoelectron spectroscopy （XPS） were used to evaluate the grafting densities. The antibacterial activities of the L-PET were investigated by using the shaking-flask method. The electron micrographs showed that the surface of the blank PET and the modified fabrics did not change. The results of XPS analysis confirmed that ε-polylysine was successfully grafted onto the surface of PET. The results of the antibacterial experiments showed that L-PET fabrics had excellent antibacterial activity against Escherichia coli and Staphylococcus aureus, and that L-PET fabrics were stable in storage for at least two years.

木糖合成纳米木聚糖在抗菌材料中的应用研究

以木糖为原料,加入适量的山梨醇与柠檬酸,以高温聚合法制备低聚木糖;随后将其与氢氧化钠溶液混合反应制备纳米木聚糖。结果表明:当木糖、山梨醇、柠檬酸的物料比为18∶6∶1,处理温度为170℃,处理时间为1 h时,低聚木糖的产率最高;当碱液浓度3.5%,处理温度为60℃,处理时间为2 h时,制得的纳米木聚糖粒径较小。抗菌试验表明:纳米木聚糖在金黄色葡萄球菌和大肠杆菌中的抑菌圈直径分别为11 mm和12 mm,显示出良好的抗菌效果。

铜复合金属材料抗菌特性试验研究

文章将大肠埃希氏菌作为试验菌种,采用平板计数法评价铜及铜复合金属材料的抗菌性能。试验中,将适宜稀释度的菌悬液分别滴加在空白样本(聚乙烯片)和实验样本(白铜片、磷铜片和铍青铜片)上接触培养一段时间,洗脱后将洗脱液涂布于平板上进行培养,并进行菌落计数,以研究铜合金材料的抗菌特性,探索铜合金抗菌材料在诸多领域的深入应用。结果表明,接触白铜、磷铜、铍青铜3种材料24 h,稀释10~5倍的菌液培养24 h后基本无菌落生长。试验结果显示,铜合金材料的平均抗菌率R≥99%,且材料中起主要抗菌作用的成分是铜。铜合金材料的抗菌率与纯铜材料的抗菌率相近,且结果均符合Ⅰ级抗细菌率标准,所以判断这三类铜合金材料均具有强抗菌效果。

一种氧化锌复合物抗菌纺织纤维材料制备及性能测试

为降低抗菌材料生物毒性,提高其抗菌性能,本试验先通过原位还原法制备氧化锌复合物,并以该复合物作为抑菌剂,结合聚酯纤维无纺布制备一种抗菌纺织纤维材料,并研究其性能。试验结果表明,当氧化锌复合物中Cu含量在4.5%以上时,抗菌纺织纤维材料抑菌率基本达到99%,抗菌性能良好;在经过50次2 g/L的AATCC 1993标准洗涤剂洗涤后,抗菌纺织纤维材料抑菌率为97.6%,耐水洗性能良好;在经过12 h、24 h细胞培养后,抗菌纺织纤维材料的细胞相对存活率分别是86.6%、85.1%,生物相容性良好。综上,该抗菌纺织纤维材料综合性能良好,具备应用价值。

抗菌PP/Rnano-ZnO复合材料的制备及性能研究

以棒状纳米氧化锌(Rnano-ZnO)为抗菌剂、聚丙烯(PP)为基材,采用熔融共混法在双螺杆挤出机中制备了抗菌PP/Rnano-ZnO复合材料。测试了复合材料的抗菌性能,通过DSC法研究了抗菌PP/Rnano-ZnO复合材料中Rnano-ZnO质量分数对结晶性能的影响,采用SEM分析了复合材料冲击断面的微观形貌,采用万能电子拉伸机测试了复合材料的力学性能。结果表明,抗菌PP/Rnano-ZnO复合材料中随着Rnano-ZnO的加入,结晶温度提高了1.81℃,相对结晶度提高了5.03%,冲击强度提高了47.83%,拉伸强度提高了20.96%和断裂伸长率提高了4790%;当抗菌PP/Rnano-ZnO复合材料中Rnano-ZnO质量分数为6.0%时,其力学性能、对大肠杆菌和金黄色葡萄球菌的抗菌效果最佳。