Silver Chloride Loaded Mesoporous Silica Particles and Their Application in the Antibacterial Coatings on Denture Base

Thiol-functionalized MCM-41 type mesoporous silica particles（MSPs） were prepared and loaded with silver chloride to act as antibacterial agents. The antibacterial activity of the silver chloride loaded MSPs（AgCI-MSPs） was evaluated by the minimum bactericidal concentration（MBC） against Candida albieans（ATCC 10231）. The AgC1-MSPs with the highest antibacterial activity were then dispersed in hybrid coatings with different mass ratios to fabricate antibacterial coatings. The antibacterial activity of the coatings was tested against Candida albicans{ATCC 10231） and Streptococcus mutans（ATCC 25175）. The resulting antibacterial coatings exhibited high antibacterial activity, good adhesion to the substrate and high hardness.     

聚(4-乙烯基吡啶季铵盐-丙烯酰胺)的抗菌性能与机理研究

季铵盐型阳离子聚合物具有絮凝、缓蚀与杀菌等多种功能,据此,我们通过分子设计,先将丙烯酰胺与4-乙烯基吡啶（4-VP）进行共聚合,然后使用季铵化试剂硫酸二甲酯使共聚物阳离子化,制备了吡啶季铵盐型阳离子聚丙烯酰胺（QPAV）,本文报道QPAV的抗菌性能,并探讨其抗菌机理,结果表明,吡啶季铵盐型阳离子聚丙烯酰胺具有很强的抗菌性能,且其抗菌机理是基于杀菌而不仅仅是抑菌。     

锌-钬共掺杂无机抗菌材料的制备及性能研究

采用溶胶-凝胶法制备了一种新型无机抗菌材料--锌-钬抗菌白炭黑。通过单因素实验和响应曲面法优化,得到了最优制备条件为:锌浓度0.711 mol·L^-1,钬浓度0.5 mmol·L^-1及反应时间65 min。获得了分散性好、粒度较小、抗菌性能良好的复合抗菌材料。通过SEM,EDS,FTIR,粒径检测和抗菌检测等手段对锌-钬抗菌白炭黑进行了表征。结果表明:锌-钬抗菌白炭黑结构蓬松,平均粒径为28.948μm,且锌离子和钬离子的添加对载体白炭黑的结构基本没有影响,其抗菌率可达83.41%。     

Antimicrobial Thiol–ene–acrylate Photosensitive Resins for DLP 3D Printing

Designing digital light processing (DLP) 3D printable photosensitive resins with antibacterial properties is especially vital because of their potential applications in various biomedical fields. In this contribution, a thiol–ene–acrylate ternary system with reduced volume shrinkage and fast photopolymerization rate was chosen as the antibacterial 3D printing matrix resin. Two quaternary ammonium salt‐type antibacterial agents (QAC and SH‐QAC) with different molecular weight were designed and prepared, which can participate in the curing of matrix resin to achieve contact antibacterial effect. The effects of antibacterial agent content on the photopolymerization kinetics and on thermal and mechanical properties were discussed in detail. When the amount of added QAC is 4wt%, the antibacterial rate is almost 100% for Escherichia coli and Staphylococcus aureus, and when the amount of SH‐QAC is 10wt%, the antibacterial rate against S. aureus is also essentially 100%. Both antibacterial photosensitive resins have been successfully applied in DLP technology to fabricate tooth model with high precision.     

茶皂素―金属复合抗菌剂的制备及抗菌性能研究

通过抑菌环法探讨了茶皂素、金属离子、茶皂素―金属复合抗菌剂对大肠杆菌和金黄色葡萄球菌的抗菌活性,考察了茶皂素纯度、浓度、金属离子种类等因素对抗菌剂抗菌活性的影响。结果表明,茶皂素的抗菌活性与单一的金属离子的抗菌活性相当,茶皂素对大肠杆菌的最低抑制浓度为5 mg/mL,对金黄色葡萄球菌的最低抑制浓度是10 mg/mL;茶皂素与金属离子复配抗菌活性具有协同效应,尤其茶皂素―锌复合抗菌剂对大肠杆菌的抑制效果大大加强。     

合成源1,4-萘醌类化合物抑菌活性研究进展

1,4-萘醌作为广泛存在的一种物质,其生物活性尤其是抗菌作用受到越来越多的关注。本文对不同取代类型的合成源1,4-萘醌衍生物进行总结,并探讨其抑菌活性及构效关系,发现在1,4-萘醌的2位引入含氨基取代、含硫取代的基团能够提高抗菌活性,且通常含硫取代比氨基取代基团的抗菌活性高。期望本文能为1,4-萘醌类抗菌药物的研发提供参考。     

Silver Chloride Loaded Hollow Mesoporous Silica Particles and Their Application in the Antibacterial Coatings on Denture Base

Hollow mesoporous silica particles(HMSPs) were prepared by using polystyrene microspheres as a template and loaded with silver chloride(AgCl) to act as antibacterial agents. The HMSPs possess radially oriented pore channels and a high loading amount of AgCl. The AgCl loaded HMSPs were then dispersed in hybrid coatings with different mass ratios to fabricate antibacterial coatings. The antibacterial activities of the coatings were tested against Candida albicans(ATCC 10231) and Streptococcus mutants(ATCC 25175). The resulting antibacterial coatings exhibited high antibacterial activities, high hardness, and acceptable adhesion to the substrate.     

Copper-Based Nanoparticles as Antibacterial Agents

Over the past few decades, the resistance of different pathogenic bacteria to various antibiotics has gradually increased. In order to solve the problems of this modern era, metal nanoparticles have attracted more attention than ever. Copper has been recognized as a non-toxic, safe inorganic material and cheap antibacterial or antifungal agent, showing potential antibacterial effect in many biomedical fields. This interest has accelerated the generation of many novel methods for the synthesis of copper-based nanoparticles. Due to the non-toxicity and safety requirements of antibacterial agents, the recent green synthesis of copper-based nanoparticles is gradually replacing the traditional methods. In addition, the antibacterial mechanism of copper-based nanoparticles has provoked great curiosity. This review summarizes the synthetic methods, the possible antibacterial mechanisms and applications of copper-based nanoparticles. Additionally, the application prospects of copper-based nanoparticle antibacterial agent in biomedical applications and clinical field have been described and discussed.     

Size-dependent bacterial growth inhibition and mechanism of antibacterial activity of zinc oxide nanoparticles

The antibacterial properties of zinc oxide nanoparticles were investigated using both gram-positive and gram-negative microorganisms. These studies demonstrate that ZnO nanoparticles have a wide range of antibacterial activities toward various microorganisms that are commonly found in environmental settings. The antibacterial activity of the ZnO nanoparticles was inversely proportional to the size of the nanoparticles in S. aureus. Surprisingly, the antibacterial activity did not require specific UV activation using artificial lamps, rather activation was achieved under ambient lighting conditions. Northern analyses of various reactive oxygen species (ROS) specific genes and confocal microscopy suggest that the antibacterial activity of ZnO nanoparticles might involve both the production of reactive oxygen species and the accumulation of nanoparticles in the cytoplasm or on the outer membranes. Overall, the experimental results suggest that ZnO nanoparticles could be developed as antibacterial agents against a wide range of microorganisms to control and prevent the spreading and persistence of bacterial infections.     

层层静电自组装构建壳聚糖/肝素抗菌多层膜的研究

聚对苯二甲酸乙二醇酯（PET）由于其突出的机械性能和良好的生物相容性而广泛用作心血管的植入材料,但是植入内置医用材料时会发生感染,这直接导致了较高的发病率和死亡率,传统的抗感染的表面设计包括与抗菌药物机械共混和表面化学接枝抗菌药物等,但是采用简单的机械共混方式制备的材料中药物负载可控性差,表面化学接枝涉及步骤繁杂的合成工艺很难在具有复杂体型结构的医用装置上实现,因此寻求一种简单的面对装置的表面修饰手段成为医用装置抗感染表面设计的关键性问题。     

Preparation of active antibacterial LDPE surface through multistep physicochemical approach: I. Allylamine grafting, attachment of antibacterial agent and antibacterial activity assessment

Low-density polyethylene (LDPE) samples were treated in air plasma discharge, coated by polyallyamine brush thought copolymeric grafting surface-from reaction and deposited four common antibacterial agents (benzalkonium chloride, bronopol, chlorhexidine and triclosan) to gain material with active antibacterial properties. Surface characteristics were evaluated by static contact angle measurement with surface energy evaluation ATR-FTIR, X-ray Photoelectron Spectroscopy (XPS) and SEM analysis. Inhibition zone on agar was used as in vitro test of antibacterial properties on two representative gram positive Staphylococcus aureus (S. aureus) and gram negative Escherichia coli (E. coli) strains. It was confirmed, that after grafting of polyallyamine, more antibacterial agent is immobilized on the surface. The highest increase of antibacterial activity was observed by the sample containing triclosan. Samples covered by bronopol did not show significant antibacterial activity.     

载银sod基纳米分子筛的合成及抗菌性能

采用两步法合成了 sod 基系列分子筛(EMT、FAU、SOD),并通过离子交换法引入 Ag⁺得到载银分子筛,通过 X 射线衍射(XRD)、扫描电子显微镜(SEM)证明离子交换前后分子筛骨架结构和晶粒尺寸没有发生明显变化;通过红外光谱(IR)、热重(TG)证明制得的载银分子筛具有良好的稳定性;对获得的载银分子筛进行了Ag⁺释放实验与抗菌能力测试,考察了分子筛种类和晶粒尺寸对抗菌性能的影响。结果表明具有笼状结构的FAU与EMT分子筛因可储存更多的Ag⁺而具有更好的抗菌性能,而具有超笼结构的 FAU 分子筛抗菌性能最优。通过对比不同晶粒尺寸载银 FAU 分子筛抗菌数据发现,晶粒尺寸为 100 nm 的载银FAU分子筛因外表面丰富的抗菌活性位点以及其内部可以储存并不断释放 Ag⁺而具有最优的抗菌性能和抗菌寿命。而晶粒尺寸为10 nm的载银FAU分子筛由于晶粒尺寸较小、外比表面积大、扩散路径短,Ag⁺的释放速率最快,抗菌效率最高。     

Bio-Organometallic Derivatives of Antibacterial Drugs

Overuse and misuse of antibacterial drugs has resulted in bacteria resistance and in an increase in mortality rates due to bacterial infections. Therefore, there is an imperative necessity of new antibacterial drugs. Bio-organometallic derivatives of antibacterial agents offer an opportunity to discover new active antibacterial drugs. These compounds are well-characterized products and, in several examples, their antibacterial activities have been studied. Both inhibition of the antibacterial activity and strong increase in the antibiotic activity of the parent drug have been found. The synthesis of the main classes of bio-organometallic derivatives of these drugs, as well as examples of the use of structure–activity relation (SAR) studies to increase the activity and to understand the mode of action of bio-organometallic antimicrobial peptides (BOAMPs) and platensimicyn bio-organometallic mimics is presented in this article.     

温敏性抗菌水凝胶的制备与控释技术研究进展

温敏水凝胶是一类通过感知温度变化使自身发生相变的智能型聚合物凝胶,通过负载抗菌剂或抗菌性单体制备抗菌水凝胶是近年来药物控制释放、组织工程以及生物免疫等领域关注的热点。本文概述了负载抗菌剂型温敏性抗菌水凝胶的物理交联和化学交联制备技术的研究概况,着重阐述了温敏性抗菌水凝胶的孔径调控、制备材料调控、载药模式调控等技术的研究进展,并对温敏性抗菌水凝胶的控释技术应用前景,特别是在生物质材料领域的应用前景进行了展望。     

Ornidazole-loaded graphene paper for combined antibacterial materials

Excellent antibacterial property of graphene oxide makes it an important antibacterial material. However, in some cases, a synergistic combination of materials with different antibacterial mechanisms is desired. In this work, we developed a simple two-step protocol to prepare ornidazole (ONZ), a nitroimidazole antiprotozoal drug, loaded graphene-based paper for combined antibacterial materials. Graphene oxide (GO) and reduced graphene oxide (rGO) were used as carriers in antibacterial materials. After mixed with ONZ directly in aqueous media and filtrated under vacuum, the freestanding GO/ONZ and rGO/ONZ were peeled off from the filtrate membrane. The ONZ loading contents in the paper was determined by UV/vis spectroscopy and the surface properties were investigated by measuring their contact angle, which will have an important impact on the antibacterial effects of the papers.     

Preparation of magnetically separable N-halamine nanocomposites for the improved antibacterial application

Magnetic N-halamine nanocomposites were synthesized through the encapsulation of the magnetic silica nanoparticles with antibacterial N-halamine polymer. The as-synthesized sample was characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and thermogravimetric analysis (TGA). The fabricated magnetic N-halamine nanocomposites possessed enhanced antibacterial activity against both gram-positive and gram-negative bacteria compared with their bulk counterparts. The effect of chlorine content of the magnetic N-halamine nanocomposites on the antibacterial activity was investigated. The magnetic N-halamine nanocomposites also exhibited super-paramagnetic behavior and had a saturation magnetization of 4.728 emu g(-1) at room temperature, which made these nanocomposites separable magnetically after the antibacterial behavior. Performances derived from the synergism between magnetic core and antibacterial shell suggest that the magnetic N-halamine nanocomposites are qualified for antibacterial applications and separable by the aid of the external magnetic field.     

Synthesis and Antibacterial Activities of Erythromycin Derivatives

Ten new erythromycin antibacterial agents containing amidino group were designed and synthesized from erythromycin via oximation, reduction and condensation. Their structures were confirmed by MS and ^13C NMR; the synthetic condition(reaction medium)was explored; and their in vtiro antibacterial activities were tested. Compound HMA-3 showed antibacterial activity against staphylococcus aureus, which is equivalent to that of erythromycin A. Compounds HMA-8 and HMA-4 also showed an antibacterial activitiy. But no compound showed bactericidal activity.     

载银sod基纳米分子筛的合成及抗菌性能

采用两步法合成了sod基系列分子筛(EMT、FAU、SOD),并通过离子交换法引入Ag⁺得到载银分子筛,通过X射线衍射(XRD)、扫描电子显微镜(SEM)证明离子交换前后分子筛骨架结构和晶粒尺寸没有发生明显变化;通过红外光谱(IR)、热重(TG)证明制得的载银分子筛具有良好的稳定性;对获得的载银分子筛进行了Ag⁺释放实验与抗菌能力测试,考察了分子筛种类和晶粒尺寸对抗菌性能的影响。结果表明具有笼状结构的FAU与EMT分子筛因可储存更多的Ag⁺而具有更好的抗菌性能,而具有超笼结构的FAU分子筛抗菌性能最优。通过对比不同晶粒尺寸载银FAU分子筛抗菌数据发现,晶粒尺寸为100 nm的载银FAU分子筛因外表面丰富的抗菌活性位点以及其内部可以储存并不断释放Ag⁺而具有最优的抗菌性能和抗菌寿命。而晶粒尺寸为10 nm的载银FAU分子筛由于晶粒尺寸较小、外比表面积大、扩散路径短,Ag⁺的释放速率最快,抗菌效率最高。     

Synthesis and antibacterial activity of pleuromutilin derivatives with novel C(14) side chain

In order to find novel antibacterial agents with superior antibacterial activity and overcoming multidrug resistance,a series of pleuromutilin derivatives with novel C(14) side chain were synthesized and evaluated for their in vitro antibacterial activities.The results of antibacterial acticities indicated that most of the derivatives showed potent activities against Gram-positive organisms.In particular,compound lOd exhibited the most potent inhibitory activity compared with pleuromutilin and linezoid,emerged as potential molecule for further investigation.     

Structure-activity relationship (SAR) studies on oxazolidinone antibacterial agents. 1. Conversion of 5-substituent on oxazolidinone

A structure-activity relationship (SAR) study on 5-substituted oxazolidinones as an antibacterial agent is described. The oxazolidinones, of which 5-acetylaminomethyl moiety was converted into other functions, were prepared and evaluated for antibacterial activity. Elongation of the methylene chain (8) and conversion of the acetamido moiety into guanidino moiety (12) decreased the antibacterial activity. The replacement of carbonyl oxygen (=O) by thiocarbonyl sulfur (=S) enhanced in vitro antibacterial activity. Especially, compound 16, which had the 5-thiourea group, showed 4-8 stronger in vitro activity than linezolid. Our SAR study revealed that the antibacterial activity was greatly affected by the conversion of 5-substituent.