BSA修饰Fe_3O_4纳米颗粒用于苦瓜提取液中活性成分的筛选

用一步法直接合成了表面氨基化修饰的Fe3O4纳米颗粒(NH2-MION),通过双功能团试剂戊二醛将牛血清白蛋白(BSA)固定在NH2-MION表面,将BSA-MION用于苦瓜提取液中活性成分的筛选,利用气相色谱-质谱联用技术鉴定出了3种与BSA作用较强的活性成分。     

Graphene oxide impregnated with iron oxide nanoparticles for the removal of atrazine from the aqueous medium

ABSTRACT

The present study proposes development of an adsorbent based on combination of graphene oxide (GO) and iron oxide (α-γ-Fe₂O₃) nanoparticles for atrazine removal from water. The synthesized adsorbent (GO@ α-γ-Fe₂O₃) was characterized using different techniques. Magnetic measurements proved that the adsorbent has superparamagnetic characteristics, thus facilitating its magnetic separation from the working suspensions. The maximum adsorption capacity was 42.5 mg g^?1. The Langmuir isotherm and the pseudo-second order kinetic models correlated adequately with the experimental data. The thermodynamic data showed that atrazine adsorption was spontaneous, endothermic and thermodynamically favorable.     

复印墨粉用四氧化三铁的制备

主要研究了在碱性条件下，由经过处理的工业级硫酸亚铁和氢氧化钠通过氧化沉淀的方法，制备适合复印墨粉用高档四氧化三铁磁粉。介绍了硫酸亚铁和氢氧化钠的反应原理、工艺流程以及不同的m（Fe）／m（NaOH）、加料方式、反应体系的pH、鼓气量、鼓气时间、以及分散剂对产品性能的影响。制备的四氧化三铁磁粉纯度高，颗粒大小均匀，磁性能好，价格低廉，能够满足国内复印机市场需求。     

Effect of iron oxide nanoparticles on the morphological properties of isotactic polypropylene

Isotactic polypropylene (iPP) and iron oxide (Fe₃O₄) nanocomposites were mixed by masterbatch blending technique in a single screw extruder machine. The concentrations of Fe₃O₄ in the iPP/Fe₃O₄ nanocomposites were 0.5, 1, 2, and 5% by weight. The influence of Fe₃O₄ nanoparticles on the effectiveness of nucleation, morphology, mode of crystallization, and crystallinity of iPP were studied by differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The introduction of Fe₃O₄ nanoparticles in the iPP matrix inhibited the formation of β crystals, and caused a shift in the melting point to higher values. The magnitude of the shift was up to 20–21°C which indicates that using the masterbatch technique leads to an enhancement of the dispersion process of the Fe₃O₄ nanoparticle and the formation of less agglomerates in the iPP/Fe₃O₄ nanocomposites. The percentage crystallinity, X_c, increased at the low cooling rates of 1 and 2°C/min. At higher cooling rates of 5, 10, and 20°C/min, the masterbatch technique produced nanocomposites of X_c with nonuniform trends. The overall crystallization rate enhancement for the iPP/Fe₃O₄ nanocomposites is attributed to the presence of Fe₃O₄ nanoparticles as a nucleating agent which have no significant effect on the growth rate of iPP crystals. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Facile modification of polysulfone hollow-fiber membranes via the incorporation of well-dispersed iron oxide nanoparticles for protein purification

Protein existence in wastewater is an important issue in wastewater management because proteins are generally present as contaminants and foulants. Hence, in this study, we focused on designing a polysulfone (PSf) hollow-fiber membrane embedded with hydrophilic iron oxide nanoparticles (IONPs) for protein purification by means of ultrafiltration. Before membrane fabrication, the dispersion stability of the IONPs was enhanced by the addition of a stabilizer, namely, citric acid (CA). Next, PSf–IONP–CA nanocomposite hollow-fiber membranes were prepared via a dry–wet spinning process and then characterized in terms of their hydrophilicity and morphology. Ultrafiltration and adsorption experiments were then conducted with bovine serum albumin as a model protein. The results that an IONP/CA weight ratio of 1:20 contributed to the most stable IONP dispersion. It was also revealed that the membrane incorporated with IONP–CA at a weight ratio of 1:20 exhibited the highest pure water permeability (58.6 L m⁻² h⁻¹ bar⁻¹) and protein rejection (98.5%) while maintaining a low protein adsorption (3.3 μg/cm²). The addition of well-dispersed IONPs enhanced the separation features of the PSf hollow-fiber membrane for protein purification. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47502.     

Influence of structure of iron nanoparticles in aggregates on their magnetic properties

Zero-valent iron nanoparticles rapidly aggregate. One of the reasons is magnetic forces among the nanoparticles. Magnetic field around particles is caused by composition of the particles. Their core is formed from zero-valent iron, and shell is a layer of magnetite. The magnetic forces contribute to attractive forces among the nanoparticles and that leads to increasing of aggregation of the nanoparticles. This effect is undesirable for decreasing of remediation properties of iron particles and limited transport possibilities. The aggregation of iron nanoparticles was established for consequent processes: Brownian motion, sedimentation, velocity gradient of fluid around particles and electrostatic forces. In our previous work, an introduction of influence of magnetic forces among particles on the aggregation was presented. These forces have significant impact on the rate of aggregation. In this article, a numerical computation of magnetic forces between an aggregate and a nanoparticle and between two aggregates is shown. It is done for random position of nanoparticles in an aggregate and random or arranged directions of magnetic polarizations and for structured aggregates with arranged vectors of polarizations. Statistical computation by Monte Carlo is done, and range of dominant area of magnetic forces around particles is assessed.     

Glucosamine conjugated iron oxide and graphene oxide nanohybrid for smart drug delivery

Smart drug delivery systems have attracted a lot of attention as one of the new treatment methods for cancer. In this study, a smart drug delivery system carrying anticancer drugs was obtained by the intelligent synthesis of glucosamine (GA)-functionalized graphene oxide (GO)-based iron oxide nanoparticles (Fe₃O₄@GO-GA) using Hummers and chemical co-precipitation processes. Nanohybrids have a high surface area (280.26 m²/g) and superparamagnetic behaviour (Ms = 26.017 emu/g), indicating a significant loading capacity (373.78 mg/mg) and efficiency (96.3%) for pharmaceutical loading. An adsorption study of conventional daunorubicin (DNR) on this carrier showed that the drug release is more prone to occur under acidic conditions (pH = 5.5), at moderately high temperatures (T = 40°C), and in the absence of smart carriers. The toxicity of the smart nanohybrids was examined using the sulphorhodamine B (SRB) assay in Michigan Cancer Foundation-7 (MCF-7) cell lines. The rate of death of cells exposed to smart drug-containing systems in comparison to the systems without GA shows that GA reduces the toxicity of Fe₃O₄@GO.     

Controlled release of curcumin from thiolated starch-coated iron oxide magnetic nanoparticles: An in vitro evaluation

Thiolated starch-coated iron oxide nanoparticles containing curcumin were developed to investigate their cytotoxicity on lymphocytes and cancer cell lines. These nanoparticles were prepared using different concentrations of thiolated starch to study the effect of polymer coating on various properties of nanoparticles, namely, yield percentage, particle size, drug encapsulation, etc. Zeta potential confirmed the stability of nanoparticles. The nanoparticles with 5% polymer coating showed drug encapsulation efficiency up to 78%, while loading efficiency was higher than 80%. The cytotoxicity assay revealed excellent compatibility of the system with lymphocyte cells while considerable amount of cytotoxicity on cancer cell lines.     

Rapid and selective separation for mixed proteins with thiol functionalized magnetic nanoparticles

ABSTRACT: Thiol group functionalized silica-coated magnetic nanoparticles (Si-MNPs@SH) were synthesized for rapid and selective magnetic field-based separation of mixed proteins. The highest adsorption efficiencies of binary proteins, bovine serum albumin (BSA; 66 kDa; pI = 4.65) and lysozyme (LYZ; 14.3 kDa; pI = 11) were shown at the pH values corresponding to their own pI in the single-component protein. In the mixed protein, however, the adsorption performance of BSA and LYZ by Si-MNPs@SH was governed not only by pH but also by the molecular weight of each protein in the mixed protein.     

The cytotoxicity evaluation of magnetic iron oxide nanoparticles on human aortic endothelial cells

One major obstacle for successful application of nanoparticles in medicine is its potential nanotoxicity on the environment and human health. In this study, we evaluated the cytotoxicity effect of dimercaptosuccinic acid-coated iron oxide (DMSA-Fe₂O₃) using cultured human aortic endothelial cells (HAECs). Our results showed that DMSA-Fe₂O₃ in the culture medium could be absorbed into HAECs, and dispersed in the cytoplasm. The cytotoxicity effect of DMSA-Fe₂O₃ on HAECs was dose-dependent, and the concentrations no more than 0.02 mg/ml had little toxic effect which were revealed by tetrazolium dye assay. Meanwhile, the cell injury biomarker, lactate dehydrogenase, was not significantly higher than that from control cells (without DMSA-Fe₂O₃). However, the endocrine function for endothelin-1 and prostacyclin I-2, as well as the urea transporter function, was altered even without obvious evidence of cell injury in this context. We also showed by real-time PCR analysis that DMSA-Fe₂O₃ exposure resulted in differential effects on the expressions of pro- and anti-apoptosis genes of HAECs. Meanwhile, it was noted that DMSA-Fe₂O₃ exposure could activate the expression of genes related to oxidative stress and adhesion molecules, which suggested that inflammatory response might be evoked. Moreover, we demonstrated by in vitro endothelial tube formation that even a small amount of DMSA-Fe₂O₃ (0.01 and 0.02 mg/ml) could inhibit angiogenesis by the HAECs. Altogether, these results indicate that DMSA-Fe₂O₃ have some cytotoxicity that may cause side effects on normal endothelial cells.     

基于化学方法制备油酸改性超顺磁性氧化铁纳米粒子

目的 油酸改性超顺磁性氧化铁纳米粒子（O-SPION）被应用于制备高品质的MRI T2阴性造影剂或搭载药物的磁靶向分子探针,不同于传统的物理合成方法,本课题组尝试采过化学方法制备O-SPION,并通过体外实验检测其细胞毒性及细胞透过性。方法 通过共沉淀法制备分散性好、磁响应强的超顺磁性纳米粒子。对油酸的羧基进行活化后,利用缩合反应实现油酸改性SPION的化学合成。采用X-Ray衍射仪、红外光谱仪、激光粒度分布测试仪、透射电镜对产物进行表征。MTT法检测其对人肝癌细胞HepG2的毒性作用,普鲁士蓝染色检测其细胞摄取能力。结果 O-SPION的核心粒径为12?.5 nm的,其具有稳定的化学结构和低表面电势,体外实验证明其低毒或无毒性,且在细胞内的摄取量较原始SPION明显增多。结论 利用化学方法成功合成了O-SPION,为进一步制备高品质MRI造影剂提供实验依据。     

磁性Ni/NiO纳米颗粒的制备及其在蛋白分离上的应用

用1∶323的硝酸镍和尿素制备出前驱物Ni2+-oligomer,于450℃下热解2 h,得到平均粒径为2 nm的磁性Ni/NiO纳米颗粒;再利用Ni2+与组氨酸的特异性结合,将Ni/NiO纳米颗粒表面修饰上组氨酸,得到平均粒径为10 nm的磁性his-Ni/NiO纳米颗粒,在大肠杆菌体内进行蛋白吸附并在体外进行提纯。结果表明,his-Ni/NiO纳米颗粒洗脱下来的蛋白与大肠杆菌中的蛋白种类一致,该研究为蛋白分离和纯化提供了一条新思路。     

Structural and magnetic characterization of norbornene-deuterated norbornene dicarboxylic acid diblock copolymers doped with iron oxide nanoparticles

A series of iron oxide doped norbornene (NOR)/deuterated norbornene dicarboxylic acid (NORCOOH) diblock copolymers were synthesized and characterized by X-ray photoelectron spectroscopy (XPS), small angle neutron scattering (SANS) and superconducting quantum interference device (SQUID) experiments. γ-Fe₂O₃ nanoparticles were synthesized within the microdomains of diblock copolymers with volume fractions of NOR/NORCOOH 0.64/0.36, 0.50/0.50 and 0.40/0.60. A spherical nanoparticle morphology was displayed in the polymer with 0.64/0.36 volume fraction. Polymers with 0.50/0.50 and 0.40/0.60 volume fractions exhibited interconnected metal oxide nanostructures. The observed changes in the shape and peak positions of the small-angle neutron scattering profiles of polymers after metal doping were related to the scattering from the metal oxide particles and to the possible deformed morphologies due to the strong interparticle interactions between metal particles, which may influence the polymer microphase separation. The combined scattering from both polymer domains and magnetic particles was depicted in SANS profiles of metal oxide doped polymers. γ-Fe₂O₃ containing block copolymers were superparamagnetic at room temperature. An increase in the blocking temperature (T_b) of interconnected nanoparticles was observed and was related to the interparticle interactions, which depends on the average distance (d) between particles and individual particle diameter (2R). The sample with volume fraction of 0.4/0.6 have the lowest d/(2R) ratio and exhibit the highest T_b at 115 K.     

酸洗废液及污泥制备磁性氧化铁颜料的工艺

以金属制品厂酸洗废液与酸洗污泥为原材料，采用湿式沉淀法制备高性能磁性氧化铁（Fe₃O₄）颜料。实验采用双氧水为氧化剂，15%石灰浆液调节反应液pH，利用蒸汽加热法为体系升温，以终点Fe³⁺/Fe²⁺比为判断依据，分析了废酸/污泥比、原液Fe³⁺/Fe²⁺比、反应时间、pH、反应温度对合成Fe₃O₄产品的影响。结果表明，随着实验不断进行，受空气影响，反应过程中Fe³⁺/Fe²⁺比是逐渐升高的；在废酸/污泥比为5∶1、原液Fe³⁺/Fe²⁺比为1.60∶1、反应时间为4h、pH为9、反应温度介于80～90℃之间条件下，合成产物色光及吸油量等指标达到氧化铁黑标准要求。本研究解决了行业内酸洗污泥资源化处置的瓶颈问题，为企业带来经济效益及环境效益。     

The effect of iron oxide nanoparticles on the mechanical relaxation of magnetic polymer hybrid films composed of a polystyrene matrix,a fractional calculus approach

A magnetic polymer hybrid film (MPHF) with a thickness of ~80 μm, composed of iron oxide nanoparticles (IONPs) in a polystyrene (PS) matrix, was successfully prepared. Its structure and morphology were analyzed by HRTEM, XRD, and FTIR. The optical and magnetic behaviors were studied by UV–Vis spectroscopy and VSM, respectively. The main relaxation of the MPHF was characterized by dynamic mechanical analysis (DMA), and the molecular mobility was analyzed by a fractional Zener model (FZM). Results obtained by DMA reveal the mechanical manifestation of the α -relaxation for both, PS and MPHF, and how this process is modified by IONPs into MPHFs. Good agreement between experimental DMA spectra and the theoretical results calculated from the FZM was obtained. Fractional parameters a and b characterize the molecular mobility at low and high temperatures, respectively. These results show that at low temperatures ( a parameter), molecular mobility is slightly affected by the presence of IONPs, while at high temperatures ( b parameter), molecular mobility is affected in a greater degree. IONPs decrease the molecular mobility of PS matrix; this effect is more pronounced at temperatures above the glass transition temperature. These results validate the effect of IONPs on PS matrix considering future applications of the MPHFs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47840.     

东阳市钾长石矿干法磁选除铁研究

分析了东阳市钾长石矿中铁的赋存状态和嵌布特性，采用于式磁选方法对该矿进行了除铁工艺研究，获得了含Ｆｅ２Ｏ３小于０．２％，产率大于８０％的精矿．研究成果巳得到了工业应用．     

Synthesis of magnetic citric‐acid‐functionalized graphene oxide and its application in the removal of methylene blue from contaminated water

A magnetic nanocomposite of citric‐acid‐functionalized graphene oxide was prepared by an easy method. First, citric acid (CA) was covalently attached to acyl‐chloride‐functionalized graphene oxide (GO). Then, Fe₃O₄ magnetic nanoparticles (MNPs) were chemically deposited onto the resulting adsorbent. CA, as a good stabilizer for MNPs, was covalently attached to the GO; thus MNPs were adsorbed much more strongly to this framework and subsequent leaching decreased and less agglomeration occurred. The attachment of CA onto GO and the formation of the hybrid were confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction spectrometry and transmission electron microscopy. The specific saturation magnetization of the magnetic CA‐grafted GO (GO‐CA‐Fe₃O₄) was 57.8 emu g^?1 and the average size of the nanoparticles was found to be 25 nm by transmission electron microscopy. The magnetic nanocomposite was employed as an adsorbent of methylene blue from contaminated water. The adsorption tests demonstrated that it took only 30 min to attain equilibrium. The adsorption capacity in the concentration range studied was 112 mg g^?1. The GO‐CA‐Fe₃O₄ nanocomposite was easily manipulated in an external magnetic field which eases the separation and leads to the removal of dyes. Thus the prepared nanocomposite has great potential in removing organic dyes. © 2014 Society of Chemical Industry