纳米载银磷酸锆抗菌聚氨酯的抗菌性能****

背景：聚氨酯材料具有优异的物理和化学性能,良好的生物相容性和抗凝血性能,且易加工成形,但聚氨酯制造的人工器官容易受到细菌等微生物的入侵。 目的：观察纳米载银无机抗菌剂对聚氨酯抗菌性能的影响。 方法：将纳米载银无机抗菌剂RHA-2,按0%(空白对照组),0.5%,1%,1.5%,2%,2.5%,5%比例添加到聚氨酯中。采用薄膜密着法检测抗菌聚氨酯对金黄色葡萄球菌、大肠杆菌的抑菌作用,并分析比较抗菌剂添加比例与聚氨酯抗菌性能的相关性。 结果与结论：添加纳米载银无机抗菌剂的聚氨酯对金黄色葡萄球菌、大肠杆菌具有良好的抑菌作用。抗菌剂添加比例0.5%~5%组对金黄色葡萄球菌的抑菌率分别为80.23%,91.32%,95.23%,99.19%,99.87%,99.93%,对大肠杆菌的抑菌率分别为76.70%,86.96%,92.92%,95.43%,99.34%,99.87%,显示抗菌性能随抗菌剂添加比例的上升而明显提高。表明纳米载银无机抗菌剂的添加赋予了聚氨酯优异的抗菌性能,且从抗菌角度出发,推荐纳米载银无机抗菌剂在聚氨酯中的添加比例不应低于1.5%。     

口腔纳米载银无机抗菌材料的抗菌性能

背景：纳米载银无机抗菌剂具有抗菌谱广、抗菌能力强等特点,是目前口腔无机抗菌材料研究的热点之一。 目的：研究纳米载银无机抗菌材料的抗菌性能及抗菌机制,为基础实验研究和临床应用提供参考信息。 方法：研究多种口腔纳米载银无机抗菌材料对常见病原菌如变形链球菌、白色念珠菌以及粘性放线菌等的抗菌性能,其中包括最低杀菌浓度以及抗菌率等,同时进行对比分析。并且研究纳米载银无机抗菌材料的抗菌机制,明确其优点与不足。 结果与结论：口腔纳米载银无机抗菌材料具有较广的抗菌谱,对变形链球菌、乳酸杆菌、粘性放线菌、白色念珠菌、牙龈卟啉单胞菌、金黄色葡萄球菌以及大肠埃希菌等均具有较强的抗菌性能,最低杀菌浓度较低,而抗菌率较高。但是同一纳米载银无机抗菌材料对不同的病原菌,其最低杀菌浓度不同,抗菌率也不同,而不同的纳米载银无机抗菌材料对同一病原菌的最低杀菌浓度也不相同,抗菌率也不同。     

纳米载银抗菌剂与四针状氧化锌抗白色念珠菌的性能

背景：口腔修复材料室温固化甲基丙烯酸甲酯的表面结构疏松多孔,极易附着各种细菌、微生物导致患者义齿性口炎的发生,所以在甲基丙烯酸甲酯中加入抗菌剂成为国内外学者研究的热点。 目的：比较加入纳米载银抗菌剂与四针状氧化锌抗菌剂后,室温固化甲基丙烯酸甲酯对白色念珠菌的抗菌活性。 方法：采用对倍稀释法测定纳米载银抗菌剂与四针状氧化锌抗菌剂对白色念珠菌的最小杀菌浓度。将纳米磷酸锆载银抗菌粉体与四针状氧化锌抗菌剂分别以0%,1%,2%,3%的质量比加入到室温固化甲基丙烯酸甲酯粉剂中,检测各组试件对白色念珠菌的抗菌率。 结果与结论：纳米载银抗菌剂对白色念珠菌的最小杀菌浓度为 40 g/L,四针状氧化锌抗菌剂对白色念珠菌的最小杀菌浓度为25 g/L。未加入纳米载银抗菌剂或四针状氧化锌抗菌剂的甲基丙烯酸甲酯几乎无抗菌活性,加入两种抗菌剂后其抗菌活性明显增加,随着加入抗菌剂质量比的增加,抗菌活性逐渐增强;当抗菌剂质量比增加到3%时,加入纳米载银抗菌剂的甲基丙烯酸甲酯抗菌率为92.23%,加入四针状氧化锌抗菌剂的甲基丙烯酸甲酯抗菌率为98.23%。表明纳米载银抗菌剂与四针状氧化锌抗菌剂对白色念珠菌均有抗菌效果,且四针状氧化锌抗菌剂比纳米载银系抗菌剂抗菌效果好。     

无机纳米抗菌材料抗菌性能在口腔正畸中的作用

背景：口腔正畸患者口内通常存在各种活动和固定矫治器,容易发生牙周炎。无机抗菌剂因具有安全性高、耐热性好、作用时间长、不易产生耐药性、抗菌谱广等优点,成为研究的热点。 目的：综述无机纳米抗菌材料在口腔正畸中的应用及研究进展。 方法：应用计算机检索PubMed数据和CNKI数据库2001年1月至2014年12月之间,有关无机纳米抗菌材料在口腔正畸治疗相关领域应用的文献,英文检索词为“Orthodontic,antibacterial agent”,中文检索词为“正畸,抗菌”。 结果与结论：无机纳米抗菌材料对口腔常见细菌均具有较好的抗菌性能,是一种比较理想的生物抗菌材料。通过对无机纳米抗菌材料的改性,可以使托槽釉质粘接剂、活动矫治器树脂材料、托槽等在发挥矫治作用的同时具有抑菌作用,降低龋坏等并发症的发生。但纳米抗菌材料在口腔正畸学中的应用研究尚处于起步阶段,改性后的材料颜色问题、物理化学性能、生物安全性等都需要进一步研究。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

钙磷涂层中掺入锌对成骨的影响及其潜在生物学机制

种植体表面涂层改性可提高其骨诱导性,其中单纯钙磷涂层已被广泛研究,但其促骨整合速率慢、抗菌性低,其他金属离子如纳米锌离子的加入可弥补这些缺陷。本文阐述了该改良涂层中纳米锌的掺入形式、对材料理化性能的影响以及抑菌性,同时归纳了钙离子、锌离子和无机磷赋予材料的生物学性能主要集中于三种无机离子对成骨细胞增殖分化、蛋白合成及基质矿化等方面的作用,以全面阐述纳米掺锌钙磷涂层对骨形成的促进作用。     

载银硅灰石涂层对变形链球菌的抑制*

背景：涂层材料本身无抗菌性,带有涂层的植入物在植入体内后也有发生感染的可能。 目的：体外实验评价载银硅灰石涂层对变形链球菌的抑制作用。 方法：用纸片扩散法测定载银硅灰石涂层材料的抑菌环大小,从而评价材料的抑菌性能优劣。 结果与结论：随着硝酸银浓度的提高,涂层载银量增加;5%载银硅石灰组抑菌环持续40 d以上,其最大直径显著大于1%载银硅石灰组抑菌环最大直径及未载银原始硅灰石涂层的抑菌环最大直径(P均< 0 .01)。结果提示,载银硅石灰涂层能缓慢释放出具有抗菌作用的Ag+,从而具有一定的抑菌性。通过加入不同初始浓度的Ag+溶液,可以在一定范围内调节载银硅石灰涂层的抑菌效率和持续时间。     

纳米载银磷酸锆抗菌聚氨酯的细胞毒性检测

背景：聚氨酯是一种研究热门的医用高分子材料,并在许多人工器官和医疗装置中发挥着至关重要的作用。 目的：制备并观察纳米载银磷酸锆抗菌聚氨酯生物材料对L929细胞增殖活性的影响及细胞毒性反应。 方法：采用MTT法检测各组抗菌聚氨酯对传代培养小鼠成纤维细胞L929的细胞毒性,L929细胞接种于96孔板,随机分为3组进行培养,实验组用抗菌聚氨酯浸提液处理,阳性对照组用苯酚溶液,阴性对照组用高密度聚乙烯浸提液,于24,48,72 h后在倒置相差显微镜下观察细胞形态,通过MTT比色法检测各组细胞的相对增殖率,并评价材料的细胞毒性。 结果与结论：实验组作用于小鼠成纤维细胞24,48,72 h后,相对增殖率分别为94.3%~97.9%,94.5%~99.8%和90.8%~96.3%,材料细胞毒性评级为Ⅰ级。提示添加低浓度纳米载银无机抗菌剂RHA-2(添加比例<5%)的热塑性聚氨酯,无细胞毒性,符合医用生物材料安全标准。     

LZB-GC纳米载银抗菌剂在藻酸盐印模材料中的抗菌性

背景：关于藻酸盐印模材料的消毒方法一直存在争议。 目的：分析LZB-GC纳米载银抗菌剂在藻酸盐印模材料中的最佳添加比例。 方法：将LZB-GC抗菌剂分别以0.125%,0.25%,0.5%,1%,1.5%,2%,2.5%的比例添加到藻酸盐印模材料中,以未添加LZB-GC抗菌剂的藻酸盐印模材料为对照,采用薄膜密着法测试其对金黄色葡萄球菌和大肠杆菌的抗菌性能。 结果与结论：随着LZB-GC抗菌剂添加量的增加,对金黄色葡萄球菌和大肠杆菌的抗菌率随之增大(P < 0.05),当添加量达到0.5%及以上,抗菌率可达到99%以上。说明LZB-GC抗菌剂在藻酸盐印模材料中的最佳添加比例为0.5%。     

纳米氧化锌抗菌性能及机制*◆

 背景：氧化锌作为一种活性氧化物类抗菌材料,拥有良好的生物相容性、安全性以及长效性。目的：总结纳米氧化锌的抗菌性能及其抗菌机制。方法：应用计算机检索1995-12/2011-02 Elsevier (ScienceDirect)及Web of Science期刊引文索引数据库相关文章,检索词为“antibacterial properties of nano-zinc oxide”,并限定文章语言种类为English。同时计算机检索1995-12/2011-02 CNKI学术总库及万方数据库相关文章,检索词为“纳米氧化锌抗菌性能”,并限定文章语言种类为中文。共检索到文献75篇。结果与结论：纳米氧化锌在很多方面的杀菌性能都很强,并且由于其良好的生物相容性、安全性以及长效性,可以取代医学上其他活性氧化物抗菌材料。文章从纳米氧化锌抗菌性能改性,以及形貌与结构对抗菌性的影响等方面,详细总结了纳米氧化锌的抗菌性能及其抗菌机制,但是如何提高纳米氧化锌的利用率和杀菌性能,如何使纳米氧化锌应用于更多细菌的抑制或更广阔的领域,都需要人们的继续努力。关键词：纳米氧化锌;抗菌材料;抗菌机制;生物材料;综述文献 doi:10.3969/j.issn.1673-8225.2012.03.033      

新型银纳米颗粒涂层薄膜材料的制备与抗菌性研究

目的制备银纳米颗粒涂层薄膜材料并检测其抗菌性。方法利用脉冲激光沉积法（PLD）将银-二氧化硅薄膜种植在衬底硅片表面,根据不同的激光脉冲沉积速率制备3组薄膜材料样品,其银与二氧化硅的含量比分别为1：3（TypeA）、1：1（TypeB）、3：1（TypeC）设为实验组,纯硅片设为对照组。使用扫描电子显微镜（SEM）、能量色散光谱仪（EDS）、原子力显微镜（AFM）对实验组样品进行物理表征,选用临床标准菌株金黄色葡萄球菌和大肠杆菌作为实验菌株进行样品体外抗菌试验。结果制备的3种样品TypeA、TypeB和TypeC应用EDS测定银纳米颗粒的含量分别为19．29％、65．32％、77．18％。SEM显示,实验组样品中银纳米颗粒镶嵌于二氧化硅的骨架结构中,结构清晰。AFM显示3种样品TypeA、TypeB和TypeC表面粗糙度良好,银纳米颗粒的大小分别为10．8、11．9和12．9nm。抗菌实验显示,接种大肠杆菌的培养基中3种样品TypeA、TypeB和TypeC的抑菌环直径分别为11、15、16mm,接种金黄色葡萄球菌的培养基中3种样品的抑菌环直径分别为15、16、17mm,所制备的银纳米颗粒涂层薄膜材料均显示出抑菌作用;对照组没有出现抑菌环。结论应用PLD方法制备银纳米颗粒抗菌薄膜材料简单易行,且材料具有良好的抑菌作用。     

Current landscape in the discovery of novel antibacterial agents

BackgroundStandard treatments against bacterial infections are becoming ineffective due to the rise of antibacterial resistance worldwide. Classical approaches to develop new antibacterial agents are not sufficient to fulfil the current pipeline, therefore new strategies are currently being devised in the field of antibacterial discovery.ObjectivesThe objective of this narrative review is to compile the most successful strategies for drug discovery within the antibacterial context that are currently being pursued.SourcesPeer-reviewed publications from the MEDLINE database with robust data addressing the discovery of new antibacterial agents in the current pipeline have been selected.ContentSeveral strategies to discover new antibacterials are described in this review: (i) derivatives of known antibacterial agents; the activity of a known antimicrobial agent can be improved through two strategies: (a) the modification of the original chemical structure of an antimicrobial agent to circumvent antibacterial resistance mechanisms and (b) the development of a compound that inhibits the mechanisms of resistance to an antibacterial agent; (ii) new antibacterial agents targeting new proteins; (iii) inhibitors of virulence factors; (iv) nanoparticles; (v) antimicrobial peptides and peptidomimetics; (vi) phage therapy and enzybiotics; and (vii) antisense oligonucleotides.ImplicationsThis review intends to provide a positive message affirming that several different strategies to design new antibacterial agents are currently being developed, and we are therefore confident that in the near future some of the most promising approaches will come to fruition.     

The formation of an antibacterial agent-apatite composite coating on a polymer surface using a metastable calcium phosphate solution

A percutaneous device with antibacterial activity and good biocompatibility is desired for clinical applications. Three types of antibacterial agent: lactoferrin (LF), tetracycline (TC), and gatifloxacin (GFLX) were immobilized on the surface of an ethylene-vinyl alcohol copolymer (EVOH) using a liquid phase coating process. In this process, an EVOH plate was alternately dipped in calcium and phosphate ion solutions, and then immersed in a metastable calcium phosphate solution supplemented with 4, 40, or 400 microg/mL of the antibacterial agent. As a result, the antibacterial agent was immobilized on the EVOH surface in the form of an antibacterial agent-apatite composite layer. The amount of immobilized antibacterial agent increased with increasing absorption affinity for apatite in the order: GFLX相似文献   

羟基磷灰石抗菌改性的研究与应用

文题释义：溶胶凝胶法：是制备羟基磷灰石的一种常用方法,其利用五氧化二磷或者磷酸盐与钙离子等溶剂反应生成溶胶或者凝胶状的化合物后,再经过高温烧结生成羟基磷灰石的一种方法。 壳聚糖：由自然界广泛存在的几丁质经过脱乙酰作用得到的化合物,法国人Rouget在1859年首先得到壳聚糖,这种天然高分子具有生物相容性、血液相容性、安全性、微生物降解性、抗菌性等优良性能,在食品、化妆品、医药、化工、金属提取及回收、水处理、生化和生物医学工程等很多领域的应用研究中取得了诸多进展。 背景：羟基磷灰石由于其良好的组织相容性及骨传导性已经被广泛应用于骨材料的研究,但单纯羟基磷灰石不具备抗菌性能,因此对羟基磷灰石进行抗菌修饰就显得非常重要。 目的：阐述羟基磷灰石抗菌修饰的相关研究进展。 方法：应用计算机检索Science Direct online数据库、PubMed、中国知网数据库,纳入建库以来至2019年发表的相关文献。检索英文关键词为“antibacterial mechanism,hydroxyapatite,Silver,Gold,copper,cobalt,chitosan,strontium,zinc,gallium,magnesium,selenium,titanium”,中文关键词“抗菌机制,抑菌机制,杀菌机制,羟基磷灰石,银,金,铜,钴,壳聚糖,锶,锌,镓,镁,硒,钛”。排除相关性低、重复文献和陈旧文献。 结果与结论：羟基磷灰石的抗菌修饰方法众多,但主要以添加金属抗菌粒子为主,银、金、铜、钴、壳聚糖、锶、锌、镓、镁、硒、钛这些物质都能添加进入羟基磷灰石并使其具有抗菌活性。目前抗菌材料的研究还存在几点不足：抗菌离子在羟基磷灰石中的释放曲线尚不能很好的调控;目前抗菌材料种类较少,能用于人体植入物的就更少,还需要发现更多无毒的具有良好抗菌性能的物质以便今后使用;由于抗菌离子具有的毒性问题,每种抗菌离子的最适抗菌离子浓度还没有一个统一标准。 ORCID: 0000-0002-1809-7037(罗进) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

Antimicrobial properties of lysozyme in relation to foodborne vegetative bacteria

The purpose of this review is to describe the antibacterial properties and mode of action of lysozyme against gram-positive and gram-negative bacteria, and to provide insight in the underlying causes of bacterial resistance or sensitivity to lysozyme. Such insight improves our understanding of the role of this ubiquitous enzyme in antibacterial defense strategies in nature and provides a basis for the development and improvement of applications of this enzyme as an antibacterial agent. The bactericidal properties of lysozyme are primarily ascribed to its N-acetylmuramoylhydrolase enzymic activity, resulting in peptidoglycan hydrolysis and cell lysis. However, an increasing body of evidence supports the existence of a nonenzymic and/or nonlytic mode of action. Because gram-negative bacteria, including some major foodborne pathogens, are normally insensitive to lysozyme by virtue of their outer membrane that acts as a physical barrier preventing access of the enzyme, several strategies have been developed to extend the working spectrum of lysozyme to gram-negative bacteria. These include denaturation of lysozyme, modification of lysozyme by covalent attachment of polysaccharides, fatty acids and other compounds, attachment of C-terminal hydrophobic peptides to lysozyme by genetic modification, and the use of outer membrane permeabilizing agents such as EDTA or polycations or permeabilizing treatments such as high hydrostatic pressure treatment.     

Porous starch-based drug delivery systems processed by a microwave route

Abstract-A new simple processing route to produce starch-based porous materials was developed based on a microwave baking methodology. This innovative processing route was used to obtain non-loaded controls and loaded drug delivery carriers, incorporating a non-steroid anti-inflammatory agent. This bioactive agent was selected as model drug with expectations that the developed methodology might be used for other drugs and growth factors. The prepared systems were characterized by 1H and 13C NMR spectroscopy which allow the study of the interactions between the starch-based materials and the processing components, i.e, the blowing agents. The porosity of the prepared materials was estimated by measuring their apparent density and studied by comparing drug-loaded and non-loaded carriers. The behaviour of the porous structures, while immersed in aqueous media, was studied in terms of swelling and degradation, being intimately related to their porosity. Finally, in vitro drug release studies were performed showing a clear burst effect, followed by a slow controlled release of the drug over several days (up to 10 days).     

Current perspectives of nanoparticles in medical and dental biomaterials

Nanotechnology is gaining tremendous impetus due to its capability of modulating metals into their nanosize, which drastically changes the chemical, physical and optical properties of metals. Nanoparticles have been introduced as materials with good potential to be extensively used in biological and medical applications. Nanoparticles are clusters of atoms in the size range of 1-100 nm. Inorganic nanoparticles and their nano-composites are applied as good antibacterial agents. Due to the outbreak of infectious diseases caused by different pathogenic bacteria and the development of antibiotic resistance, pharmaceutical companies and researchers are searching for new antibacterial agents. The metallic nanoparticles are the most promising as they show good antibacterial properties due to their large surface area to volume ratios, which draw growing interest from researchers due to increasing microbial resistance against metal ions, antibiotics and the development of resistant strains. Metallic nanoparticles can be used as effective growth inhibitors in various microorganisms and thereby are applicable to diverse medical devices. Nanotechnology discloses the use of elemental nanoparticles as active antibacterial ingredient for dental materials. In dentistry, both restorative materials and oral bacteria are believed to be responsible for restoration failure. Secondary caries is found to be the main reason to restoration failure. Secondary caries is primarily caused by invasion of plaque bacteria (acid-producing bacteria) such as Streptococcus mutans and lactobacilli in the presence of fermentable carbohydrates. To make long-lasting restorations, antibacterial materials should be made. The potential of nanoparticles to control the formation of biofilms within the oral cavity is also coming under in- creasing scrutiny. Possible uses of nanoparticles as topically applied agents within dental materials and the appli- cation of nanoparticles in the control of oral infections are also reviewed.     

Antimicrobial Properties of Lysozyme in Relation to Foodborne Vegetative Bacteria

The purpose of this review is to describe the antibacterial properties and mode of action of lysozyme against Gram-positive and Gram-negative bacteria, and to provide insight in the underlying causes of bacterial resistance or sensitivity to lysozyme. Such insight improves our understanding of the role of this ubiquitous enzyme in antibacterial defense strategies in nature and provides a basis for the development and improvement of applications of this enzyme as an antibacterial agent. The bactericidal properties of lysozyme are primarily ascribed to its N-acetylmuramoylhydrolase enzymic activity, resulting in peptidoglycan hydrolysis and cell lysis. However, an increasing body of evidence supports the existence of a nonenzymic and/or nonlytic mode of action. Because Gram-negative bacteria, including some major foodborne pathogens, are normally insensitive to lysozyme by virtue of their outer membrane that acts as a physical barrier preventing access of the enzyme, several strategies have been developed to extend the working spectrum of lysozyme to Gram-negative bacteria. These include denaturation of lysozyme, modification of lysozyme by covalent attachment of polysaccharides, fatty acids and other compounds, attachment of C-terminal hydrophobic peptides to lysozyme by genetic modification, and the use of outer membrane permeabilizing agents such as EDTA or polycations or permeabilizing treatments such as high hydrostatic pressure treatment.