Biocompatible Polymer Coated Paramagnetic Nanoparticles for Doxorubicin Delivery: Synthesis and Anticancer Effects Against Human Breast Cancer Cells

To increase the efficacy of doxorubicin in induction of apoptosis, pH-responsive nanocarriers with an average particle size of 20 nm by using chitosan-polymethacrylic acid (CTS-PMAA) shells and Fe₃O₄ cores via in situ polymerization approach were synthesized. Doxorubicin hydrochloride (DOX) was loaded effectively to nanocarrier through electrostatic interactions and strong hydrogen banding. The cumulative release of DOX-loaded nanoparticles was pH dependent with a maximum release rate at pH 5.8. In vitro cytotoxicity assay revealed the biocompatibility of blank nanocarrier and superior anticancer performance of DOX-loaded nanoparticles verified by DAPI staining and MTT assay tests.     

磁性纳米粒子在生物学及医学领域的应用

磁性纳米粒子由于其生物相客性和低毒性而广泛应用于生物医学领域.阐述了近年来磁性纳米粒子在生物分离、生物检测、靶向药物输送、磁共振成像、肿瘤磁感应热疗等生物学和医学领域中的应用进展,并指出其主要发展方向和亟待解决的问题.     

PEG-co-Polyvinyl Pyridine Coated Magnetic Mesoporous Silica Nanoparticles for pH-Responsive Controlled Release of Doxorubicin

In the present work a pH responsive drug nanocarrier based on magnetic mesoporous silica nanoparticles (MMSN) and polyethylene glycol-co-polyvinyl pyridine (PEG-co-PVP) was prepared. The core-shell nanocarrier was formed due to electrostatic interaction between protonated polyvinyl pyridine and surface modified MMSN with carboxylate groups. This carrier was used for pH-controllable doxorubicin release. The maximum release was occurred at pH 5.5 (pH of endosomes). This carrier was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, UV-Vis spectrophotometer, scanning electron microscope, and high-resolution transmission electron microscope techniques. Also the zeta potential value and dynamic light scattering were measured. All characterizations confirmed the core-shell structure of the drug nanocarrier.     

紫外分光光度法测定琼脂糖磁性纳米粒的四氧化三铁含量

目的:采用紫外分光光度法测定琼脂糖磁性纳米粒的四氧化三铁含量。方法:将琼脂糖磁性纳米粒用硝酸硝化后,游离出铁离子与邻菲罗啉形成橙红色配合物,用分光光度法测定吸光度。结果:铁离子与邻菲罗啉生成的配合物,在510 nm波长处有最大吸收;在0.0036~0.036μmol/m L浓度范围内,吸光度与浓度之间呈良好的线性关系,标准曲线为A=11.436C-0.0006,R2=0.9999;总平均回收率99.91%,RSD=0.81%(n=9)。结论:该方法操作简便,结果准确可靠,适用于测定琼脂糖磁性纳米粒的四氧化三铁含量。     

磷酸化聚乙烯醇修饰磁性纳米粒子对铀酰的吸附性能研究

在Fe3O4磁性纳米粒子表面复盖一层磷酸化聚乙烯醇制备了一种用于从水相选择性分离铀酰的复合型磁性纳米粒子。用平衡吸附法研究了纳米粒子对铀酰的吸附性能和选择识别能力,且探讨了实验条件对纳米粒子吸附性能的影响。结果表明在竞争金属离子存在下,纳米粒子对铀酰具有较高的吸附能力和选择识别能力,且可以循环使用。     

The Proteolytic Landscape of Ovarian Cancer: Applications in Nanomedicine

Ovarian cancer (OvCa) is one of the leading causes of mortality globally with an overall 5-year survival of 47%. The predominant subtype of OvCa is epithelial carcinoma, which can be highly aggressive. This review launches with a summary of the clinical features of OvCa, including staging and current techniques for diagnosis and therapy. Further, the important role of proteases in OvCa progression and dissemination is described. Proteases contribute to tumor angiogenesis, remodeling of extracellular matrix, migration and invasion, major processes in OvCa pathology. Multiple proteases, such as metalloproteinases, trypsin, cathepsin and others, are overexpressed in the tumor tissue. Presence of these catabolic enzymes in OvCa tissue can be exploited for improving early diagnosis and therapeutic options in advanced cases. Nanomedicine, being on the interface of molecular and cellular scales, can be designed to be activated by proteases in the OvCa microenvironment. Various types of protease-enabled nanomedicines are described and the studies that focus on their diagnostic, therapeutic and theranostic potential are reviewed.     

Syntheses of Fe-Ni Magnetic Nanoparticles and Their Applications on Biologic Labeling

In this study, we compared FeNi alloy magnetic nanoparticles (MNPs) prepared by either combustion or chemical precipitation methods. We found that the FeNi MNPs generated by combustion method have a rather high saturation magnetization Ms of～180 emu/g and a coercivity field Hc of near zero. However, the alloy nanoparticles are easily aggregated and are not well dispersive such that size distribution of the nanoparticle clusters is wide and clusters are rather big (around 50～700 nm). To prepare a better quality and well dispersed Fe-Ni MNPs, we also developed a thermal reflux chemical precipitation method to synthesize FeNi3 alloy MNPs. The precursor chemicals of Fe(acac)3 and Ni(acac)2 in a molecular ratio 1,2-hexadecandiol and tri-n-octylphosphine oxide (TOPO) were used as reducer and surfactant, respectively. The chemically precipitated FeNi3 MNPs are well dispersed and have well-controlled particle sizes around 10～20 nm with a very narrow size distribution (±1.2 nm). The highly monodispersive FeNi3 MNPs present good uniformity in particle shape and crystallinity on particle surfaces. The MNPs exhibit well soft magnetism with saturation magnetization of ～61 emu/g and Hc～0. The biomedically compatible FeNi MNPs which were coated with biocompatible polyethyleneimine (PEI) polymer were also synthesized. We demonstrated that the PEI coated FeNi MNPs can enter the mammalian cells in vitro and can be used as a magnetic resonance imagine (MRI) contrast agent. The results demonstrated that FeNi MNPs potentially could be applied in the biomedical field. The functionalized magnetic beads with biocompatible polymer coated on MNPs are also completed for biomedical applications.     

Chemical Synthesis of Monodisperse Magnetic Nanoparticles for Sensitive Cancer Detection

This short tutorial review highlights the advance in high temperature solution phase chemical synthesis of monodisperse magnetic nanoparticles (MNPs), especially iron oxide NPs, as contrast enhancement agents for cancer detection by magnetic resonance imaging (MRI). It introduces briefly the unique nanomagnetism of MNPs required for MRI. It then summarizes some typical methods used to prepare monodisperse Fe₃O₄ and ferrite MFe₂O₄ MNPs from high temperature organic phase reaction with controlled magnetic properties. It further outlines the chemistry used to make these MNPs biocompatible and target-specific. Finally it presents two examples to demonstrate the MNP control achieved from chemical synthesis for sensitive detection of cancer.     

Magnetic Nanoparticles: Surface Effects and Properties Related to Biomedicine Applications

Due to finite size effects, such as the high surface-to-volume ratio and different crystal structures, magnetic nanoparticles are found to exhibit interesting and considerably different magnetic properties than those found in their corresponding bulk materials. These nanoparticles can be synthesized in several ways (e.g., chemical and physical) with controllable sizes enabling their comparison to biological organisms from cells (10–100 μm), viruses, genes, down to proteins (3–50 nm). The optimization of the nanoparticles’ size, size distribution, agglomeration, coating, and shapes along with their unique magnetic properties prompted the application of nanoparticles of this type in diverse fields. Biomedicine is one of these fields where intensive research is currently being conducted. In this review, we will discuss the magnetic properties of nanoparticles which are directly related to their applications in biomedicine. We will focus mainly on surface effects and ferrite nanoparticles, and on one diagnostic application of magnetic nanoparticles as magnetic resonance imaging contrast agents.     

Magnetic Iron Oxide Nanoparticles for Multimodal Imaging and Therapy of Cancer

Superparamagnetic iron oxide nanoparticles (SPION) have emerged as an MRI contrast agent for tumor imaging due to their efficacy and safety. Their utility has been proven in clinical applications with a series of marketed SPION-based contrast agents. Extensive research has been performed to study various strategies that could improve SPION by tailoring the surface chemistry and by applying additional therapeutic functionality. Research into the dual-modal contrast uses of SPION has developed because these applications can save time and effort by reducing the number of imaging sessions. In addition to multimodal strategies, efforts have been made to develop multifunctional nanoparticles that carry both diagnostic and therapeutic cargos specifically for cancer. This review provides an overview of recent advances in multimodality imaging agents and focuses on iron oxide based nanoparticles and their theranostic applications for cancer. Furthermore, we discuss the physiochemical properties and compare different synthesis methods of SPION for the development of multimodal contrast agents.     

Phosphocholine-Modified Magnetic Nanoparticles for Isolation of C-Reactive Protein from Human Serum

In the present study, we describe the easy isolation of C-reactive protein (CRP) from human serum using phosphocholine-modified magnetic nanoparticles (MNPs). A phosphocholine-based monomer, 3-(4)-vinylbenzyl-12-phosphorylcholine dodecanoate (VPC), was polymerized on methacrylate-coated MNPs and the resulting MNPs (VPC-MNPs) were assessed for their ability to isolate CRP from a human serum sample. CRP could be isolated from human serum with one adsorption step to VPC-MNPs within 1 h. The high purity of the isolated CRP fraction determined by SDS-PAGE indicates a good selectivity of VPC-MNPs for CRP binding. These results demonstrate the feasibility of using ligand-functionalized MNPs for rapid, easy, and efficient protein isolation.     

Sustained Release of Prindopril Erbumine from Its Chitosan-Coated Magnetic Nanoparticles for Biomedical Applications

The preparation of magnetic nanoparticles coated with chitosan-prindopril erbumine was accomplished and confirmed by X-ray diffraction, TEM, magnetic measurements, thermal analysis and infrared spectroscopic studies. X-ray diffraction and TEM results demonstrated that the magnetic nanoparticles were pure iron oxide phase, having a spherical shape with a mean diameter of 6 nm, compared to 15 nm after coating with chitosan-prindopril erbumine (FCPE). Fourier transform infrared spectroscopy study shows that the coating of iron oxide nanoparticles takes place due to the presence of some bands that were emerging after the coating process, which belong to the prindopril erbumine (PE). The thermal stability of the PE in an FCPE nanocomposite was remarkably enhanced. The release study showed that around 89% of PE could be released within about 93 hours by a phosphate buffer solution at pH 7.4, which was found to be of sustained manner governed by first order kinetic. Compared to the control (untreated), cell viability study in 3T3 cells at 72 h post exposure to both the nanoparticles and the pure drug was found to be sustained above 80% using different doses.     

Magnetic Field-Assisted Laser Ablation of Titanium Dioxide Nanoparticles in Water for Anti-Bacterial Applications

Journal of Inorganic and Organometallic Polymers and Materials - Titanium oxide nanoparticles (TiO2) were produced by pulsed Nd:YAG laser ablation in water under the effect of an external magnetic...     

Monodisperse and Corrosion-Resistant Metallic Nanoparticles Embedded into Sepiolite Particles for Optical and Magnetic Applications

The preparation of large quantities of heterogeneous materials containing non-agglomerated and monodispersed nanoparticles is becoming one of the bottlenecks that hinders the development of commercial devices. Here we describe a method to prepare monodispersed metallic (Cu, Ag, Au, Ni, Co, and Fe) nanoparticles in a silicate matrix (sepiolite) by means of a reduction process of metallic cations associated with a dehydration process of the matrix. This process is characterized by the huge amount of monodispersed metallic nanoparticles that it produces. Additionally, these nanoparticles have been revealed to be remarkably stable against oxidation because the transformed sepiolite matrix becomes a diffusion barrier for oxygen. Furthermore, the nanoparticles present suitable properties to be used for optical and magnetic applications.     

纳米磁流体及其在癌症治疗中的应用研究进展

对纳米磁流体的组成、制备、应用进行了详细的综述。对纳米磁流体的制备方进行了评价,着重介绍了国内外纳米磁流体在癌症治疗中的应用研究进展。     

Synthesis and Characterization of Sulfamic-Acid Functionalized Magnetic Fe3O4 Nanoparticles Coated by Poly(amidoamine) Dendrimer

Grafting of chlorosulfuric acid on the amino-functionalized Fe₃O₄ nanoparticles produced sulfamic acid-functionalized magnetic Fe₃O₄ nanoparticles as a novel organic–inorganic hybrid material, which was characterized with X-ray diffractometry (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, scanning electron spectroscopy, and magnetization measurements (VSM). The as-prepared nanocomposite with a narrow size distribution has the crystallite size from XRD (11 ± 4 nm) and particle size from TEM analysis (12.9 ± 0.4 nm) are consistent with each other. Magnetization measurements proved the superparamagnetic property of the product.     

Enzymatic Synthesis of Magnetic Nanoparticles

We report the first in vitro enzymatic synthesis of paramagnetic and antiferromagnetic nanoparticles toward magnetic ELISA reporting. With our procedure, alkaline phosphatase catalyzes the dephosphorylation of l-ascorbic-2-phosphate, which then serves as a reducing agent for salts of iron, gadolinium, and holmium, forming magnetic precipitates of Fe_45±14Gd_5±2O_50±15 and Fe_42±4Ho_6±4O_52±5. The nanoparticles were found to be paramagnetic at 300 K and antiferromagnetic under 25 K. Although weakly magnetic at 300 K, the room-temperature magnetization of the nanoparticles found here is considerably greater than that of analogous chemically-synthesized Ln_xFe_yO_z (Ln = Gd, Ho) samples reported previously. At 5 K, the nanoparticles showed a significantly higher saturation magnetization of 45 and 30 emu/g for Fe_45±14Gd_5±2O_50±15 and Fe_42±4Ho_6±4O_52±5, respectively. Our approach of enzymatically synthesizing magnetic labels reduces the cost and avoids diffusional mass-transfer limitations associated with pre-synthesized magnetic reporter particles, while retaining the advantages of magnetic sensing.     

Innovative Strategy for MicroRNA Delivery in Human Mesenchymal Stem Cells via Magnetic Nanoparticles

Bone marrow derived human mesenchymal stem cells (hMSCs) show promising potential in regeneration of defective tissue. Recently, gene silencing strategies using microRNAs (miR) emerged with the aim to expand the therapeutic potential of hMSCs. However, researchers are still searching for effective miR delivery methods for clinical applications. Therefore, we aimed to develop a technique to efficiently deliver miR into hMSCs with the help of a magnetic non-viral vector based on cationic polymer polyethylenimine (PEI) bound to iron oxide magnetic nanoparticles (MNP). We tested different magnetic complex compositions and determined uptake efficiency and cytotoxicity by flow cytometry. Additionally, we monitored the release, processing and functionality of delivered miR-335 with confocal laser scanning microscopy, real-time PCR and live cell imaging, respectively. On this basis, we established parameters for construction of magnetic non-viral vectors with optimized uptake efficiency (~75%) and moderate cytotoxicity in hMSCs. Furthermore, we observed a better transfection performance of magnetic complexes compared to PEI complexes 72 h after transfection. We conclude that MNP-mediated transfection provides a long term effect beneficial for successful genetic modification of stem cells. Hence, our findings may become of great importance for future in vivo applications.     

玻璃纤维涂层织物的技术与应用

玻璃纤维涂层织物是在玻璃纤维织物表面涂覆一层涂层材料,不仅可以充分发挥玻璃纤维固有的性能特点,还可以赋予织物新的性能,以满足不同应用领域的需求。介绍了各种涂层材料的特性、各种涂覆工艺的特点及涂层织物的应用情况。     

Synthesis and Characterization of Asparaginase Bound Silver Nanocomposite Against Ovarian Cancer Cell Line A2780 and Lung Cancer Cell Line A549

Development of new strategies of drug delivery is essential for effective treatment of cancer. In the present work, nanobiocomposite of fungal asparaginase was produced by immobilizing with silver nanoparticles. Asparaginase bound silver nanoparticle has shown higher enzyme activity than crude asparaginase. The primary and secondary amine/amide functional groups were found responsible for binding of asparaginase to silver nanoparticles. The silver nanobiocomposite of asparaginase was found to have smooth surface and crystalline in nature. The size of the nanobiocomposites ranged from 60 to 80 nm. The cytotoxicity of silver nanobiocomposite of asparaginase was found to be higher than free asparaginase on ovarian cancer cell line. The silver nanobiocomposite of asparaginase showed better cytotoxicity against ovarian cancer cell line A2780 than lung cancer cell line A549. Thus the synthesized silver nanobiocomposite of asparaginase can be used as an effective anticancer agent against lung cancer.