The impact of size on tissue distribution and elimination by single intravenous injection of silica nanoparticles

Many approaches for the application of nano-sized particles to the human body as nanotechnology have been recently developed. The size of nanoparticles is related to their useful character and also plays a key role in toxicity. Since this surface area can interact with biological components of cells, nanoparticles can be more reactive in than larger particles.     

ALTERATIONS OF NEUTROPHIL FUNCTIONS IN FOUNDRY AND POTTERY WORKERS

ABSTRACT

To assess the immune competence of workers occupationally exposed to mainly silica, neutrophil functions such as the chemotactic and oxidative burst activity in foundry and pottery workers were evaluated. The chemotactic activity was examined in 22 foundry and 10 pottery workers and oxidative burst activity of neutrophils were determined in 22 foundry and 6 pottery workers. Healthy subjects of comparable age, sex, and smoking habits and with no history of silica exposure were used as the control groups. Chemotaxis was carried out in Boyden chambers using Zymosan activated serum as chemotactic stimulus. Oxidative burst activity was measured using nitroblue tetrazolium (NBT) dye reduction test. Both neutrophil functions were significantly reduced in silica-exposed foundry and pottery workers (p<0.001) compared to controls suggesting that human chronic exposure mainly to silica and other chemicals originated from foundry and pottery settings may diminish neutrophil functions in humans.     

FasL在染矽尘大鼠肺组织细胞不同时间点的表达

【目的】探讨FasL在矽肺肺纤维化过程中的作用。【方法】随机将Wistar大鼠分为对照组和染矽尘组。采用暴露式气管内一次注入二氧化硅粉尘悬液建立大鼠矽肺模型。模型建立后,分4个时间点(7、14、21、28 d),每组分别取8只大鼠将其处死取肺组织,用组织芯片技术结合免疫组化SP法观察大鼠肺组织不同时间点FasL的表达情况,采用Image-Pro Plus Version 4.5 for windowsTM图像分析计算积分光密度。【结果】大鼠矽肺模型组肺组织FasL在染矽尘后的7、14、21和28 d时,表达显著高于对照组,差异有显著性(P<0.05),表达高峰是在染矽尘后的14 d。【结论】肺组织FasL的表达与矽肺纤维化的发生发展有关。     

多聚赖氨酸-硅纳米颗粒的生物相容性研究

背景与目的：多聚赖氨酸-硅纳米颗粒是一种新型的非病毒纳米颗粒基因传递载体。本研究主要阐述其生物相容性,为其进一步的体内应用提供实验依据。方法：细胞转染和流式细胞仪分析在含血清培养基中多聚赖氨酸-硅纳米颗粒介导质粒DNA和反义寡核苷酸的转染能力,随后通过血浆蛋白反应滤过试验和红细胞聚集试验进一步评价其生物相容性。结果：在含血清培养基中,多聚赖氨酸-硅纳米颗粒介导质粒DNA和反义寡核苷酸传递的能力显著下降。多聚赖氨酸-硅纳米颗粒／DNA(／ODN)复合物可与小鼠血浆蛋白成分结合,并可引起红细胞聚集。结论：多聚赖氨酸-硅纳米颗粒可能与含血清培养基中的血浆蛋白相互作用,影响体外细胞转染效率。多聚赖氨酸-硅纳米颗粒可能与体内外周血血浆蛋白和外周血红细胞反应而影响其体内基因传递能力,其生物相容性还有待于进一步提高。     

染矽尘大鼠血浆一氧化氮、一氧化氮合酶的变化

目的　探讨染矽尘不同时点大鼠血浆NO (一氧化氮 )、NOS (一氧化氮合酶 )的变化。方法　采用析因分析的研究设计进行实验 ;气管注射染尘方法建立动物模型 ;称量法测定脏器系数 ;硝酸还原酶法测定血浆NO水平 ;NOS催化L Arg法测定血浆NOS活性。结果　在染尘后第 30天时 ,实验组血浆NO水平高于对照组 (P <0 0 5) ,其他时点差异没有显著性 ,但有升高趋势 ;在染尘后第 2 1、 30、 60天时 ,实验组血浆NOS活力显著低于对照组。控制时间因素进行偏相关分析结果显示实验组血浆NO水平和血浆NOS活力为负相关 (r=- 0 367,P =0 0 2 8)。结论　矽尘可导致大鼠血浆NO水平升高和血浆NOS活力的降低     

Enzyme-linked immunofiltration assay used in the screening of solid supports and immunoreagents for the development of an azinphos-methyl flow immunosensor

Azinphos-methyl (AM), O,O-dimethyl S-[(4-oxo-1,2,3-benzotriazin-3(4H)-yl)methyl] phosphorodithioate, is a dithiophosphorous insecticide extensively used for the control of fruit culture pests. In this work the ELIFA system, initially developed and marketed to substitute conventional ELISA methods, was used for the screening of supports and immunoreagents in the development of a flow immunosensor to AM. The objective was to find the optimal antibody concentration, support quantity and enzymatic tracer concentration to develop a sensitive and reusable immunosensor. The influence of chitosan as protein stabilizing agent was also investigated. We observed that, on the basis of immunosorbent characterization, chitosan-modified silica with immobilized LIB-MFH14 monoclonal antibody (MAb) showed the best sensitivity, with a I₅₀ value of 6 nM AM. All of the immobilized MAbs either in alkylaminated or chitosan-modified silica showed I₅₀ values between 10 and 36 nM. Regarding the regeneration capability, the best desorption agent tested was 0.1 M glycine/HCl, pH 2.0, performing in most cases a 100% desorption after just one wash and maintaining the antibody activity even after 20 cycles of regeneration. The chitosan-modified silica seemed to be the best support for this purpose.     

矽尘相关性自身免疫病的研究进展

长期二氧化硅粉尘暴露可引起矽肺,同时也引起自身免疫功能异常,可能导致自身免疫病,如类风湿性关节炎、系统性硬化症、系统性红斑狼疮、特发性炎症性肌病、抗中心粒细胞胞质抗体相关性血管炎等。矽肺、自身免疫病可以单独发生,也可以合并存在。本文对矽尘相关性自身免疫病的概念、流行病学、临床特征以及可能的作用机制进行综述,以期提高对疾...     

Interaction of folate – Linked silica nanoparticles with HeLa cells: Analysis and investigation the effect of polymer length

This work is a continuance to our previous findings on silica nanoparticles (NPs) modified with diamine polymer, carboxymethyl-β-cyclodextrin (CM-β-CD) and folic acid (FA), respectively. When four different polymer lengths (D230, D400, D2000 and D4000) were analyzed, the release rate of anticancer agents was inversely related to the polymer length while the cell toxicity was directly related to the length. We investigate here the effect of polymer length on the extent of cellular interaction with HeLa cells. The mean particle size, the polydispersity (PD) and the zeta potential of the NPs were measured using dynamic light scattering (DLS), the quantitative analysis of the extent of NPs'' interaction was studied using fluorescence microscopy and transmission electron microscopy (TEM) was used to qualitatively visualize them. The particle size increased by increasing the polymer length, the PD values were within the acceptable ranges (0.3−0.5) and the zeta potential was in the range of (−16 to −20 mV). A direct relation was observed between the fluorescence intensity and the length. All modified NPs were capable of entering the cells, however a greater number of NPs with long polymers was observed compared to short polymers. Thus, the direct relation of polymer length to the cell toxicity is due to the release rate behavior and the enhanced interaction of NPs which possess long polymers.     

自体软骨真皮联合硅胶假体隆鼻术29例临床效果

目的：探讨自体软骨、真皮联合硅胶假体隆鼻术临床效果.方法：取适当的耳甲腔软骨、自体真皮、瘢痕皮、无细胞同种真皮,附在L形硅胶假体鼻尖部,置入鼻背筋膜下进行隆鼻.结果：本组29例随访3个月～4年,未发生假体下滑、移位、脱出,效果满意.结论：应用耳软骨、自体真皮、瘢痕皮、无细胞同种真皮可加强鼻尖部自体组织厚度,联合硅胶假体隆鼻术可避免假体下滑、移位和外露等并发症的发生.     

自体耳软骨与硅胶假体联合隆鼻术

目的探讨应用耳软骨加强鼻尖部自体组织的厚度,并与硅胶假体联合置入隆鼻的方法。方法取适当的耳甲腔软骨雕刻成型,附在硅胶假体鼻尖部,置入鼻背筋膜下,进行隆鼻。结果本组患者39例,其中2例术后1周出现假体偏斜,1个月后自然好转;1例术后6个月假体鼻根部活动并抬高,经再次手术后满意。余患者随访6个月至2年,效果满意。结论应用耳软骨可加强鼻尖部自体组织厚度,耳软骨联合硅胶假体隆鼻术可避免假体下滑、移位和外露等并发症的出现,值得临床推广应用。