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。     

几种常用载银抗菌材料改性方式的研究现状

背景：银系抗菌剂具有生物安全性高,抗菌谱广,不产生耐药性等特点,是口腔无机抗菌剂中研究的热点。 目的：围绕几种常用银系无机抗菌剂载体结构、载银原理及对其载银方式、载银环境等改性增强其抗菌效果和改善原材料缺陷的研究现状作以综述。 方法：应用计算机检索CNKI数据库、OVID数据库2000/2010有关银系抗菌剂及其载体的相关文章。 结果与结论：无论是传统的沸石、磷酸盐等载体,还是新型的纳米载银方式,人们都从材料本身特征及其载银特质方面不断改性,以期得到用量更少,抑菌性能更优及克服了变色等性能缺陷的优质载银抗菌剂。以后载银无机抗菌材料的开发,除了可以更进一步地利用纳米载银以外,还可以往复合抑菌,缓释抑菌以及将抑菌作为其他材料的添加辅助性能等方面发展。     

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：     

P型纳米二氧化硅载银抗真菌耐高温及稳定性试验的研究

目的:研究P型纳米二氧化硅载银抗菌粉抗真菌效果及耐热性和稳定性。方法:(1)测定不同浓度,不同作用时间的抗真菌率。(2)耐高温和稳定性测试。结果:P型纳米二氧化硅载银抗菌粉浓度越高抗真菌效果越好,作用时间越长抗真菌效果越好。最小抑菌浓度,P型纳米二氧化硅载银抗菌粉(含银0.35%)1 g 5 mL水与白色念珠菌作用20分钟平均抑菌率可达70.21%。P型纳米二氧化硅载银抗菌粉置于94℃电热恒温水浴锅中放置14天后,配制浓度为1 g 5 mL的药液与白色念珠菌作用20分钟,抗真菌率仍可达到56.25%。结论:P型纳米二氧化硅载银抗菌稳定性很好,耐高温、不失效。     

纳米氧化锌对白色念珠菌的抗菌作用

背景：纳米氧化锌作为无机抗菌剂,与有机杀菌剂的抗菌机制明显不同。 目的：探讨纳米氧化锌对白色念珠菌等真菌的抗菌作用。 方法：分别配制成100,75,50,25,10 g/L的纳米氧化锌与普通氧化锌悬浊液,以生理盐水作为阴性对照,采用KB纸片扩散法将30 μL不同浓度悬浊液分别作用于白色念珠菌,将培养平板上置于37 ℃恒温箱培养24 h观察并测量抑菌圈大小。 结果与讨论：随着纳米氧化锌浓度的提高,对白色念珠菌的抑制作用逐渐增强,抑菌圈直径逐渐增大。普通氧化锌的无明显抑菌作用。证实纳米氧化锌能够抑制白色念珠菌等真菌的生长。     

钴铬合金表面镀氮化锆涂层对细菌黏附性能的影响

背景：细菌黏附与钴铬合金材料的表面性能密切相关,因此近年来材料的表面改性技术成了该领域的研究重点。 目的：验证钴铬合金表面所镀氮化锆薄膜是否可以改善义齿金属材料的细菌黏附性能。 方法：应用磁控溅射沉积方法在钴铬合金材料表面镀氮化锆薄膜,制备钴铬合金镀膜组试件(实验组),以未镀膜的钴铬合金试件为对照组,分别将变形链球菌、白色念珠菌和黏液放线菌接种在两组试件的测试面上,待培养结束时进行菌落计数。 结果与结论：细菌黏附实验结果显示,实验组3种细菌的菌落计数均低于对照组,差异有显著性意义(P < 0.05),对照组的细菌黏附数量明显高于镀膜组。提示：钴铬合金表面所镀氮化锆薄膜可以显著降低变形链球菌、白色念珠菌及黏性放线菌的黏附数量,从而改善钴铬合金材料的细菌黏附性能。  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     

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      

载银磷酸锆可影响293T细胞的生长与增殖

背景：研究表明6种国内外知名品牌口腔抗菌纳米载银无机抗菌剂中载银磷酸锆的杀菌性和安全性最佳。 目的：进一步观察载银磷酸锆对体外培养人胚肾上皮293T细胞生长、超微结构及胰岛素样生长因子1表达与分泌的影响。 方法：采用CCK-8方法检测5,2.5,1.25,0.625 g/L载银磷酸锆稀释液对293T细胞增殖的影响。根据结果选择对细胞增殖影响最大的质量浓度处理293T细胞,光学倒置显微镜观察细胞形态变化,于透射电镜下观察细胞超微结构及代谢变化,RT-PCR检测细胞胰岛素样生长因子1 mRNA的表达,ELISA法检测细胞培养上清液中胰岛素样生长因子1蛋白的水平。 结果与结论：载银磷酸锆作用于293T细胞48 h,1.25 g/L组细胞毒性为Ⅱ级,轻度细胞毒性,其余质量浓度组均为Ⅰ级,无细胞毒性。1.25 g/L载银磷酸锆处理293T细胞24,36,48 h后,细胞形态发生异常,细胞膜破损,出现轻度中毒现象,尤以48 h表现明显。1.25 g/L载银磷酸锆处理48 h后,293T细胞中胰岛素样生长因子1 mRNA的表达及上清液中胰岛素样生长因子1蛋白水平与正常培养细胞差异无显著性意义(P > 0.05)。表明载银磷酸锆影响293T细胞的生长及增殖,具有一定的细胞毒性,其在牙科材料中的应用还有待于进一步研究。     

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%。     

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。     

TiO2-xNx抗菌托槽的抑菌性能

 背景：有研究表明TiO_2-xN_x薄膜对变形链球菌、黏性放线菌及白色念珠菌具有良好的抗菌效果。目的：进一步评价TiO_2-xN_x薄膜托槽的抗菌性能。 方法：纳入10例正畸患者,将口内牙齿以上下中线分为左右两侧,分别粘接普通金属托槽和TiO_2-xN_x薄膜托槽,在矫治前、矫治后1,2,3,4周检测正畸菌斑指数、牙龈指数、龈沟出血指数及釉质脱矿指数。结果与结论：普通金属托槽组矫治后1,2,3,4周的正畸菌斑指数、牙龈指数、龈沟出血指数及釉质脱矿指数均高于矫治前(P < 0.05);TiO_2-xN_x薄膜托槽组矫治后3周的牙龈指数高于矫治前(P < 0.05),矫治后1,2,3周的龈沟出血指数高于矫治前(P < 0.05),矫治后2,3,4周的釉质脱矿指数高于矫治前(P < 0.05);TiO_2-xN_x薄膜托槽组矫治后1-4周的正畸菌斑指数、龈沟出血指数均低于普通金属托槽组(P < 0.05),矫治后2-4周的牙龈指数、釉质脱矿指数均低于普通金属托槽组(P < 0.05)。表明TiO_2-xN_x薄膜托槽具有较好的抗菌效果,可更好地控制和清除菌斑。中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Coagglutination reactions between Candida albicans and oral bacteria

An agglutination assay for detecting intermicrobial adherence between the cells of Candida albicans and various oral bacteria is described. Strains of Streptococcus sanguis, S. salivarius, S. mutans, S. mitis, Fusobacterium nucleatum and Actinomyces viscosus all coagglutinated with C. albicans. No interaction could be demonstrated between the cells of Bacteroides melaninogenicus and those of C. albicans. Preliminary investigations of these interactions suggest that binding of F. nucleatum and A. viscosus to C. albicans is mediated by bacterial proteins, possibly lectins. Other mechanisms must account for the binding of oral streptococci to C. albicans. The possible implications of these findings in relation to oral mucosal colonisation and oral candidal clearance are discussed.     

纳米银生物安全性及其在树脂基托中的应用

背景：近年来纳米银已在医学生物学领域得到了广泛应用,它具有很稳定的物理化学性能,且广谱抗菌,效力持久,无耐药性。随着越来越多的纳米银产品被研制出来,对它的生物安全性研究也逐渐引起人们的关注。 目的：围绕纳米银的生物安全性研究现状作以综述,并初步分析其在树脂基托中的抗菌作用及对基托性能的影响。 方法：于2000/2010应用计算机检索CNKI数据库、PUDMED数据库,OVID数据库中有关银系无机抗菌剂及其在基托树脂中的应用等相关文章,挑选出有代表性的30篇中英文文献做进一步分析。 结果与结论：讨论纳米银生物安全性这个问题时,要从形态,尺寸粒径,剂量等方面综合考虑,不能简单的说是有毒的还是无毒的。此外,纳米银对口腔常见致病菌如变形链球菌、乳杆菌、白色念珠菌有较强杀菌作用,将其应用到树脂基托中可以预防和治疗义齿性口炎,但如何克服基托氧化变色等问题仍有待进一步研究。     

Production, purification, and properties of a bacteriocin from Staphylococcus aureus isolated from saliva.

Staphylococci from samples of human saliva were isolated on staphylococcal-selective agar plates. These strains were tested for the inhibition of the growth of Staphylococcus aureus FDA209P. The frequency of inhibitory strains among all of the staphylococcal isolates was 5.2%. Strain IYS2, which formed the biggest inhibitory zone against the growth of the indicator strain, was used as the producer of bacteriocin. IYS2 was identified to be S. aureus, based on its biological properties. The bacteriocin was purified by sequential procedures, including ammonium sulfate precipitation, fractionation with ethanol, ion-exchange chromatography, and gel filtration. Its molecular weight was determined to be 5,000. The isoelectric point was 10.0. In amino acid composition, lysine, histidine, aspartic acid, valine, and phenylalanine were predominant. The bacteriocin was heat stable but inactivated by proteases or peptidase. The bacteriocin had a bactericidal effect on susceptible cells. An analysis of the inhibitory spectrum among typical oral indigenous bacteria showed that Streptococcus salivarius, Propionibacterium acnes, Corynebacterium parvulum, and Actinomyces israelii were susceptible to the bacteriocin. Streptococcus mutans, Streptococcus sanguis, Streptococcus mitis, Actinomyces viscosus, Actinomyces naeslundii, Fusobacterium nucleatum, Bacterionema matruchotii, and Bacteroides melaninogenicus were resistant. The majority of S. aureus tested were susceptible, and all Staphylococcus epidermidis strains tested were resistant.     

Human beta-defensins 2 and 3 demonstrate strain-selective activity against oral microorganisms

Human beta-defensins 2 and 3 (HBD-2 and HBD-3) are inducible peptides present at sites of infection in the oral cavity. A few studies have reported broad-spectrum antimicrobial activity for both peptides. However, no comprehensive study has thoroughly investigated their potential against oral pathogens. The purpose of this study was to test the effectiveness of HBD-2 and HBD-3 against a collection of oral organisms (Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Peptostreptococcus micros, Actinomyces naeslundii, Actinomyces israelii, Streptococcus sanguis, Streptococcus mutans, Candida tropicalis, Candida parapsilosis, Candida krusei, Candida glabrata, and Candida albicans). Radial diffusion assays were used to test HBD-2 and HBD-3 activities against at least three strains of each species. There was significant variability in MICs, which was strain specific rather than species specific. MICs ranged from 3.9 to >250 micro g/ml for HBD-2 and from 1.4 to >250 micro g/ml for HBD-3. HBD-3 demonstrated greater antimicrobial activity and was effective against a broader array of organisms. Overall, aerobes were 100% susceptible to HBD-2 and HBD-3, whereas only 21.4 and 50% of the anaerobes were susceptible to HBD-2 and HBD-3, respectively. HBD-2 and HBD-3 also demonstrated strain-specific activity against the Candida species evaluated. Interestingly, an association between HBD-2 and HBD-3 activities was noted. This suggests that the two peptides may have similar mechanisms yet utilize distinct pathways. The lack of activity against specific anaerobic strains and Candida warrants further investigation of the potential resistance mechanisms of these organisms. Finally, the significant variability between strains underlies the importance of testing multiple strains when evaluating activities of antimicrobial peptides.     

Salivary-agglutinin-mediated adherence of Streptococcus mutans to early plaque bacteria.

Interspecies binding is important in the colonization of the oral cavity by bacteria. Streptococcus mutans can adhere to other plaque bacteria, such as Streptococcus sanguis and Actinomyces viscosus, and this adherence is enhanced by saliva. The salivary and bacterial molecules that mediate this interaction were investigated. Salivary agglutinin, a mucinlike glycoprotein known to mediate the aggregation of many oral streptococci in vitro, was found to mediate the adherence of S. mutans to S. sanguis or A. viscosus. Adherence of S. mutans to saliva- or agglutinin-coated S. sanguis and A. viscosus was inhibited by antibodies to the bacterial agglutinin receptor. Expression of the S. sanguis receptor (SSP-5) gene in Enterococcus faecalis increased adhesion of this organism to saliva- or agglutinin-coated S. sanguis and A. viscosus. This interaction could be inhibited by antibodies to the agglutinin receptor. The results suggest that salivary agglutinin can promote adherence of S. mutans to S. sanguis and A. viscosus through interactions with the agglutinin receptor on S. mutans.     

Quaternary ammonium silane-functionalized, methacrylate resin composition with antimicrobial activities and self-repair potential

The design of antimicrobial polymers to address healthcare issues and minimize environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol-gel chemical route; these compounds possess flexible Si-O-Si bonds. In present work, a partially hydrolyzed QAMS co-polymerized with 2,2-[4(2-hydroxy 3-methacryloxypropoxy)-phenyl]propane is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. The kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) and Candida albicans (ATCC 90028). Improved mechanical properties after hydration provided the proof-of-concept that QAMS-incorporated resin exhibits self-repair potential via water-induced condensation of organic modified silicate (ormosil) phases within the polymerized resin matrix.