Phagocytosis and endocytosis of silver nanoparticles induce interleukin-8 production in human macrophages

Phagocytosis or endocytosis by macrophages is critical to the uptake of fine particles, including nanoparticles, in order to initiate toxic effects in cells. Here, our data enhance the understanding of the process of internalization of silver nanoparticles by macrophages. When macrophages were pre-treated with inhibitors to phagocytosis, caveolin-mediated endocytosis, or clathrin-mediated endocytosis, prior to exposure to silver nanoparticles, Interleukin-8 (IL-8) production was inhibited. Although cell death was not reduced, the inflammatory response by macrophages was compromised by phagocytosis and endocytosis inhibitors.     

纳米Ag/TiO2涂层托槽对口腔常见细菌的抗菌性能研究

目的:检测纳米Ag/TiO2涂层托槽对口腔常见细菌的抗菌性能.方法:通过扫描电镜检测纳米Ag/TiO2涂层托槽表面微观形态;采用贴膜法研究纳米Ag/TiO2涂层对口腔常见细菌的抗菌性能.结果:本研究合成的纳米Ag/TiO2涂层为具有严整组织结构的纳米颗粒膜;纳米Ag/TiO2涂层对口腔常见细菌20min黑暗环境下抗茵率均达到79％以上.结论:纳米Ag/TiO2涂层托槽对口腔常见细菌有较强的抗菌效果.     

光致还原制备透明质酸-纳米银复合物

以透明质酸(HA)为分散载体,通过紫外光还原硝酸银制备出了Ag纳米颗粒分散体系。用紫外-可见光分光光度计(UV-Vis)、傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)、动态激光光散射(DLS)及抑菌实验对所得样品的形貌、结构及性质进行表征。结果表明：所制备的Ag纳米颗粒呈球形,平均粒径约为18 nm,在水相中能稳定分散,且对金黄色葡萄球菌(S.aureus)具有明显的抑菌作用。     

乳糖化-去甲斑蝥素及其纳米粒在Caco-2细胞模型中的跨膜转运机制

目的 研究乳糖化-去甲斑蝥素（Lac-NCTD）及其壳聚糖纳米粒（Lac-NCTD-NPs）的细胞摄取、转运机制。方法 采用Caco-2细胞单层模型研究Lac-NCTD和Lac-NCTD-NPs的摄取和跨膜转运;考察了时间、温度、pH值、药物质量浓度、吸收抑制剂和促进剂对药物跨膜吸收的影响,并比较两种剂型吸收过程的差异。结果 Lac-NCTD以主动转运为主要方式被细胞摄取和转运,少部分通过旁路转运。药物的摄取和时间呈正相关,与温度呈负相关。P-糖蛋白（P-gp）和多药耐药相关蛋白2（MRP2）抑制剂能增加Lac-NCTD的细胞摄取（P＜0.05）。药物从基底侧（basolateral,BL）到肠腔侧（apical,AP）的渗透系数（P_app(BL→AP)）大于P_app(AP→BL)。内吞抑制剂氧化苯砷对药物的转运无影响,旁路转运促进剂去氧胆酸钠能增加药物转运。结论 Lac-NCTD主要以主动转运方式被吸收,少部分通过旁路转运被Caco-2细胞摄取和转运,此过程受P-gp和MRP2外排蛋白作用,且药物纳米粒的摄取和转运较其溶液均有增加。     

血红蛋白基纳米氧载体:结构特点、高铁含量控制及血循环中持久存在(英文)

Due to the continuously insufficient supply and the disadvantages associated with the donated blood,artificial blood substitute has received extensive attentions throughoutthe world in recentyears.Nano-structured hemoglobin-based oxygen carriers (NHOCs),in particular the liposome-encapsulated hemoglobin (LEH) and hemo-globin-based polymeric nanoparticles (HbPNPs),which combine the nanotechnology with the traditional cellular oxygen carriers,have shown great potential applications in blood transfusion,thrombus and cancer therapy as well.The present article firstly reports on the current status of the synthesis,properties,clinical trial and application of the LEHand HbPNPs.And then,attentions are devoted to highlight the main challenges and the proposed strategies of the NHOCs with the respect of suppression of the methemoglobin formation and prolonging the blood circulation time.These results make us confident in advancing further development of NHOCs,with the expectation of their eventual commercialization.     

Gene expression of zebrafish embryos exposed to titanium dioxide nanoparticles and hydroxylated fullerenes

Increased release of engineered nanoparticles to the environment suggests a rising need for the monitoring and evaluation of potential toxicity. Zebrafish frequently have been used as a model species in human and aquatic toxicology studies. In this study, zebrafish embryos were microinjected in the otic vesicle with a sublethal dose of engineered nanoparticles (titanium dioxide/TiO₂ and hydroxylated fullerenes/C₆₀(OH)₂₄). A gene microarray analysis was performed on injected and control embryos to determine the potential for nanoparticles to change the expression of genes involved in cross talk of the nervous and immune systems. The exposure to TiO₂ and hydroxylated fullerenes caused shifts in gene regulation response patterns that were similar for downregulated genes but different for upregulated genes. Significant effects on gene regulation were observed on genes involved in circadian rhythm, kinase activity, vesicular transport and immune response. This is the first report of circadian rhythm gene deregulation by nanoparticles in aquatic animals, indicating the potential for broad physiological and behavioral effects controlled by the circadian system.     

Single-molecule protein arrays enabled by scanning probe block copolymer lithography

The ability to control the placement of individual protein molecules on surfaces could enable advances in a wide range of areas, from the development of nanoscale biomolecular devices to fundamental studies in cell biology. Such control, however, remains a challenge in nanobiotechnology due to the limitations of current lithographic techniques. Herein we report an approach that combines scanning probe block copolymer lithography with site-selective immobilization strategies to create arrays of proteins down to the single-molecule level with arbitrary pattern control. Scanning probe block copolymer lithography was used to synthesize individual sub-10-nm single crystal gold nanoparticles that can act as scaffolds for the adsorption of functionalized alkylthiol monolayers, which facilitate the immobilization of specific proteins. The number of protein molecules that adsorb onto the nanoparticles is dependent upon particle size; when the particle size approaches the dimensions of a protein molecule, each particle can support a single protein. This was demonstrated with both gold nanoparticle and quantum dot labeling coupled with transmission electron microscopy imaging experiments. The immobilized proteins remain bioactive, as evidenced by enzymatic assays and antigen-antibody binding experiments. Importantly, this approach to generate single-biomolecule arrays is, in principle, applicable to many parallelized cantilever and cantilever-free scanning probe molecular printing methods.     

超声辐照促纳米多聚体释放DNA的体内研究

目的 通过研究不同超声参数与绿色荧光蛋白表达之间的关系,探讨超声辐照促进绿色荧光蛋白基因(GFP)与雄激素受体抗体标记的PLGA纳米颗粒(NP-PLGA-GFP-AR)的体内降解与释放的作用.方法 建立人前列腺癌PC-3细胞裸鼠动物模型,将NP-PLGA-GFP-AR纳米粒注射于瘤内2 h后,对癌瘤使用不同强度和类型的超声进行局部辐照,通过激光共聚焦荧光显微镜观察GFP表达,从而评价转染效果.结果 粒径优选后的纳米粒能稳定转染GFP与雄激素受体抗体标记的DNA质粒,超声辐照组较非辐照组的GFP表达提前,占空比为50%的连续波超声较脉冲波超声对前列腺癌的转染效果好.结论 优化后的超声辐照可有效靶向增强体内DNA转染,局部超声辐照结合特异PLGA纳米粒能有效用于DNA靶向递送.

Abstract：

Objective To investigate the feasibility and the efficacy of ultrasound in promoting PLGA nanoparticle-mediated gene transfection in vivo.Methods Prostate cancer cell line PC-3 was used to generate xenografts in nude mice for gene transfection experiment in vivo.GFP plasmid was encapsulated in PLGA-based nanoparticles.Nanoparticles were injected into tumors locally.Two hours later,xenografts were exposed to ultrasound.Xenograft tissues were harvested in different time points to assess the efficiency of gene expression with regard to different parameters of ultrasound. Results PLGA nanoparticle-encapsulated GFP plasmids were readily transfected to PC-3 cells in vivo.A large number of GFP expressing cells were observed after exposed to ultrasound with 1.0 MHz 50% duty factor continuous wave.In comparison,ultrasound exposure with 40% duty factor pulse wave in vivo had low efficacy in terms of GFP expression.No animal death was noticed due to ultrasound exposure.Conclusions Ultrasound exposure can enhance the release of plasmid DNA content delivered by PLGA nanoparticles in vivo,local exposure to ultrasound wave would be used in conjunction with PLGA nanoparticle-mediated targeted delivery to the tissue or organ of interest.     

生物纳米siRNA颗粒抑制丙型肝炎病毒复制的体外研究

目的研究携带针对丙型肝炎病毒（HcV）I洲A的小干扰RNA（siRNA）的生物可降解性纳米颗粒在体外对HCV复制的抑制作用。方法采用“一锅合成法”制备携带针对HCVRNA的siRNA的D－半乳糖－多聚乙酰亚胺－磷酸钙纳米颗粒,噻唑盐（MTT）法检测该纳米颗粒的细胞毒性,荧光分光光度法检测该siRNA纳米颗粒对HcV的抑制作用。结果该纳米siRNA颗粒对肝原代细胞无毒性作用,在HcV细胞培养系统中,可被肝肿瘤细胞（Huh7．5．1）摄取进入细胞内,抑制HcV病毒载量超过1log100。结论D－半乳糖－多聚乙酰亚胺－磷酸钙生物可降解性纳米siRNA颗粒为治疗HCV感染提供了新的手段,具有一定发展前景。