Long-term Pulmonary Responses to Quadweekly Intermittent Intratracheal Spray Instillations of Magnetite (Fe3O4) Nanoparticles for 52 Weeks in Fischer 344 Rats

Information about potential risks of iron nanomaterials is still limited, while a wide variety of applications are expected. We recently reported acute phase responses of male and female Fischer 344 rats after a single intratracheal spray instillation of Fe₃O₄ nanoparticles (magnetite), clearly showing dose-dependent pulmonary inflammatory changes (Tada et al., J Toxicol Pathol 25, 233–239, 2012). The present study assessed long-term responses of male and female Fischer 344 rats to multiple administrations of magnetite. Ten-week-old male and female Fischer 344 rats (n=20/group) were exposed to a total of 13 quadweekly intermittent intratracheal spray instillations of magnetite during the experimental period of 52 weeks, at doses of 0, 0.2 (low), 1.0 (medium) and 5.0 (high-dose) mg/kg body weight per administration. Absolute and relative lung weights of the high-dose group were significantly higher than those of the control group. Macroscopically, slight enlargement and scattered black patches were recognized in the lungs and the lung-associated lymph nodes of the high-dose group. Histopathologically, infiltration of macrophages phagocytosing magnetite (all dose groups) and of chronic inflammatory cells (medium- and high-dose males and high-dose females), alveolar bronchiolization and granuloma (high-dose group) were observed. In addition, alveolar hyperplasias were observed in some rats of the high-dose group, and cytoplasmic overexpression of β-catenin protein was immunohistochemically found in such lesions. The present results clearly show that instilled magnetite causes chronic inflammatory responses in the lung. These responses occur in a dose-dependent manner without apparent differences among sexes     

一株地衣芽孢杆菌合成纳米金的研究

以山西老陈醋醋醅中分离的一株地衣芽孢杆菌菌体(Bacillus licheni formis)作为还原剂,以氯金酸(HAuCl4)为原料,采用生物法合成纳米金粒子.研究结果显示,通过紫外可见分光光度法、X射线衍射和透射电子显微镜镜进行了表征后,分析得到合成的纳米金的紫外吸收峰值为545 nm,其粒径为15(±28％) nm,其结晶呈球形,为面心立方结构.X射线衍射仪表征图谱与已报道的纳米金图谱一致.     

环境水体中纳米氧化铜对金鱼藻的毒性效应研究

采用模拟水体环境的方法,研究了低浓度(2～8 mg·L-1)纳米氧化铜(CuONPs)溶液对金鱼藻生长的毒性影响,并与相同浓度的微米氧化铜和可比剂量铜离子进行对比分析.实验结果显示在纳米氧化铜溶液的作用下,金鱼藻对Cu元素的积累量为相同浓度的微米氧化铜溶液作用下的6～12倍,金鱼藻体内的酶活性对纳米氧化铜溶液作用的浓度和时间均有明显反应.在作用20 d时,4mg·L-1的纳米氧化铜溶液作用下金鱼藻体内POD、SOD活性均达到最大值;在作用30 d时,同样浓度作用下金鱼藻的叶绿素含量达到峰值,其后逐步下降.对于8 mg· L-1纳米氧化铜溶液的可比剂量铜离子(0.23 mg· L-1)作用于金鱼藻,其POD活性、SOD活性和叶绿素含量的变化明显小于8 mg· L-1浓度的纳米氧化铜溶液.上述结果表明低浓度(4～8 mg·L-1)的纳米氧化铜溶液对金鱼藻生长有明显的抑制效应和毒害作用,纳米氧化铜对金鱼藻的生长表现出很强的纳米效应,其生长同时受到纳米氧化铜溶液作用时间的影响,但低浓度的微米氧化铜溶液对金鱼藻生长几乎不存在毒害作用.     

纳米碳酸钙原位改性竹纤维表面性能的研究

采用离子溶液反应法将碳酸钙沉积到竹纤维上,研究在不同浓度氯化钙溶液下的碳酸钙原位沉积情况及其对单根竹纤维表面形貌、粗糙度及润湿性等性能的影响。结果表明:随着氯化钙溶液浓度的增大,碳酸钙吸附量呈上升趋势,从0.97%增至12.3%;碳酸钙由分散性较好的不规则四面体单晶逐渐团聚生长为球形或椭球形,单晶为60 nm左右;附着的碳酸钙颗粒改变了纤维的表面粗糙度和浸润性能;不同水平间改性纤维的表面粗糙度和静态接触角存在显著差异,氯化钙溶液浓度为0.3 mol/L时,单根竹纤维的表面粗糙度值达到最大、静态接触角最小。      

Development of a monoclonal antibody against deoxynivalenol for magnetic nanoparticle-based extraction and an enzyme-linked immunosorbent assay

Monoclonal antibody (mAb, NVRQS-DON) against deoxynivalenol (DON) was prepared. DON-Ag coated enzyme linked immunosorbent assay (ELISA) and DON-Ab coated ELISA were prepared by coating the DON-BSA and DON mAb. Quantitative DON calculation ranged from 50 to 4,000 ng/mL for DON-Ab coated ELISA and from 25 to 500 ng/mL for DON-Ag coated ELISA. 50% of inhibitory concentration values of DON, HT-2, 15-acetyl-DON, and nivalenol were 23.44, 22,545, 5,518 and 5,976 ng/mL based on the DON-Ab coated ELISA. Cross-reactivity levels of the mAb to HT-2, 15-acetyl-DON, and nivalenol were 0.1, 0.42, and 0.40%. The intra- and interassay precision coefficient variation (CV) were both <10%. In the mAb-coated ELISA, mean DON recovery rates in animal feed (0 to 1,000 µg/kg) ranged from 68.34 to 95.49% (CV; 4.10 to 13.38%). DON in a buffer solution (250, 500 and 1,000 ng/mL) was isolated using 300 µg of NVRQS-DON and 3 mg of magnetic nanoparticles (MNPs). The mean recovery rates of DON using this mAb-MNP system were 75.2, 96.9, and 88.1% in a buffer solution spiked with DON (250, 500, and 1,000 ng/mL). Conclusively we developed competitive ELISAs for detecting DON in animal feed and created a new tool for DON extraction using mAb-coupled MNPs.     

Development and Characterization of VEGF165-Chitosan Nanoparticles for the Treatment of Radiation-Induced Skin Injury in Rats

Radiation-induced skin injury, which remains a serious concern in radiation therapy, is currently believed to be the result of vascular endothelial cell injury and apoptosis. Here, we established a model of acute radiation-induced skin injury and compared the effect of different vascular growth factors on skin healing by observing the changes of microcirculation and cell apoptosis. Vascular endothelial growth factor (VEGF) was more effective at inhibiting apoptosis and preventing injury progression than other factors. A new strategy for improving the bioavailability of vascular growth factors was developed by loading VEGF with chitosan nanoparticles. The VEGF-chitosan nanoparticles showed a protective effect on vascular endothelial cells, improved the local microcirculation, and delayed the development of radioactive skin damage.     

纳米硅材料对植物生长发育影响的研究进展

随着纳米技术的快速发展,其在植物和农业上的应用已逐渐引起广泛兴趣。作为纳米材料的一种,纳米硅由于独特的结构和物理化学性质被广泛应用。纳米硅材料不断增加的生产和应用是否对环境中的植物及农作物带来影响,是一个值得关注的问题。本文就近年来国内外在纳米硅材料与植物相互作用及其对植物生长发育影响的研究进行了详细综述。首先介绍植物对纳米硅材料的吸附和吸收,分析纳米硅在植物体内的运输方式并描述纳米硅在植物体内的积累和分布情况;随后,详细介绍了纳米硅材料对植物不同生长发育阶段的影响,并分析了该影响产生的生理和分子机理;接着分析了纳米硅材料对植物抗逆性的影响及其原因;阐述了纳米硅作为肥料对植物（尤其是农作物）的应用效果;最后概括了纳米硅材料与植物互作研究中存在的问题、理论深度以及进一步的研究方向,并提出了具体建议,以期为纳米硅材料在农业生产上的安全、高效利用提供参考。     

纳米改性高密度聚乙烯耐老化性能的研究进展

高密度聚乙烯（HDPE）是性能优异的通用合成树脂,在工农业生产中有着广泛的应用,在渔业上主要是用作深水抗风浪网箱框架材料.但由于HDPE作为网箱框架材料在户外使用时存在着严重的老化现象,一旦其出现严重的老化不仅严重影响到网箱的使用寿命,甚至由于HDPE框架的老化产生断裂会造成巨大的经济损失.本文归纳并阐述了HDPE的老化机理,阐述了用无机纳米粒子改性HDPE进而提高其耐老化性能,重点归纳了几种用于改性HDPE的无机纳米粒子及其特性,阐明了这几种无机纳米粒子改性HDPE耐老化的机理和优势,总结了国内外无机纳米粒子表面处理方法及纳米改性HDPE耐老化性能的最新研究进展及发展趋势.     

Production of a Novel Fucoidanase for the Green Synthesis of Gold Nanoparticles by Streptomyces sp. and Its Cytotoxic Effect on HeLa Cells

Marine actinobacteria-produced fucoidanases have received considerable attention as one of the major research topics in recent years, particularly for the medical exploitation of fucoidans and their degradation products. The present study describes the optimization and production of a novel fucoidanase for the green synthesis of gold nanoparticles and its biological applications. The production of fucoidanase was optimized using Streptomyces sp. The medium components were selected in accordance with the Plackett-Burman design and were further optimized via response surface methodology. The fucoidanase was statistically optimized with the most significant factors, namely wheat bran 3.3441 g/L, kelp powder 0.7041 g/L, and NaCl 0.8807 g/L, respectively. The biosynthesized gold nanoparticles were determined by UV-vis spectroscopy and were further characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis, and high-resolution transmission electron microscopy. Furthermore, the biosynthesized gold nanoparticles exhibited a dose-dependent cytotoxicity against HeLa cells and the inhibitory concentration (IC₅₀) was found to be 350 µg/mL at 24 h and 250 µg/mL at 48 h. Therefore, the production of novel fucoidanase for the green synthesis of gold nanoparticles has comparatively rapid, less expensive and wide application to anticancer therapy in modern medicine.     

ORIGINAL ARTICLE: Changes in composition a metabolism of caecal microbiota in rats fed diets supplemented with copper‐loaded chitosan nanoparticles

The study was conducted to investigate the effect of copper‐loaded chitosan nanoparticles on the composition and metabolism of the caecal microbiota in rats. Forty male Sprague–Dawley (SD) rats (average body weight of 82 ± 5 g) were randomly assigned to five groups (n = 8). The dietary treatments were: (i) basal diet, (ii) basal diet + 80 mg/kg BW CuSO₄, (iii) basal diet + 80 mg/kg BW chitosan (CS‐I), (iv) basal diet + 80 mg/kg BW copper‐loaded chitosan nanoparticles (CSN‐I) and (v) basal diet + 160 mg/kg BW copper‐loaded chitosan nanoparticles (CSN‐II). The trial lasted 21 days. The results showed that compared with control, Average day gain (ADG) of group CSN‐I and CSN‐II increased (p < 0.05). No significant difference was found in CuSO₄ or CS‐I‐treated groups (p > 0.05). There were no effects of these treatments on average day feed intake (ADFI) of rats (p > 0.05). The counts of Bifidobacteria and Lactobacillus in group CSN‐II were higher than those of the control group (p < 0.05), while the counts of total aerobes, total anaerobes, Salmonella, Clostridium and coliform were lower than those of the control (p < 0.05). The activity of β‐glucuronidase in group CSN‐I or CSN‐II was significantly depressed (p < 0.05), while the activities of α‐galactosidase and β‐galactosidase were enhanced significantly (p < 0.05). The pH of the caecum digesta and the concentration of propionate and butyrate in group CSN‐I and CSN‐II were higher than those of the control group (p < 0.05). No significant difference was found in these parameters in CuSO₄ or CS‐I‐treated groups (p > 0.05). The results indicate that the microbiota and environment of caecum are beneficially changed by the administration of copper‐loaded CSN.