https://iopscience.iop.org/article/10.1088/1468-6996/16/2/023501/pdf

Recent progress on magnetic iron oxide nanoparticles: synthesis, surface functional strategies and biomedical applications.

Multidrug resistance of the pathogenic microorganisms to the antimicrobial drugs has become a major impediment toward successful diagnosis and management of infectious diseases. Recent advancements in nanotechnology-based medicines have opened new horizons for combating multidrug resistance in microorganisms. In particular, the use of silver nanoparticles (AgNPs) as a potent antibacterial agent has received much attention. The most critical physico-chemical parameters that affect the antimicrobial potential of AgNPs include size, shape, surface charge, concentration and colloidal state. AgNPs exhibits their antimicrobial potential through multifaceted mechanisms. AgNPs adhesion to microbial cells, penetration inside the cells, ROS and free radical generation, and modulation of microbial signal transduction pathways have been recognized as the most prominent modes of antimicrobial action. On the other side, AgNPs exposure to human cells induces cytotoxicity, genotoxicity and inflammatory response in human cells in a cell-type dependent manner. This has raised concerns regarding use of AgNPs in therapeutics and drug delivery. We have summarized the emerging endeavors that address current challenges in relation to safe use of AgNPs in therapeutics and drug delivery platforms. Based on research done so far, we believe that AgNPs can be engineered so as to increase their efficacy, stability, specificity, biosafety and biocompatibility. In this regard, three perspectives research directions have been suggested that include 1) synthesizing AgNPs with controlled physico-chemical properties, 2) examining microbial development of resistance towards AgNPs, and 3) ascertaining the susceptibility of cytoxicity, genotoxicity, and inflammatory response to human cells upon AgNPs exposure.

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Mechanistic Basis of Antimicrobial Actions of Silver Nanoparticles.

A biotechnological perspective on the application of iron oxide magnetic colloids modified with polysaccharides

Iron oxide nanoparticles (NPs) hold great promise for future biomedical applications because of their magnetic properties as well as other intrinsic properties such as low toxicity, colloidal stability, and surface engineering capability. Numerous related studies on iron oxide NPs have been conducted. Recent progress in nanochemistry has enabled fine control over the size, crystallinity, uniformity, and surface properties of iron oxide NPs. This review examines various synthetic approaches and surface engineering strategies for preparing naked and functional iron oxide NPs with different physicochemical properties. Growing interest in designed and surface-engineered iron oxide NPs with multifunctionalities was explored in in vitro/in vivo biomedical applications, focusing on their combined roles in bioseparation, as a biosensor, targeted-drug delivery, MR contrast agents, and magnetic fluid hyperthermia. This review outlines the limitations of extant surface engineering strategies and several developing strategies that may overcome these limitations. This study also details the promising future directions of this active research field.

Designed synthesis and surface engineering strategies of magnetic iron oxide nanoparticles for biomedical applications

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The Basics of Crystallography and Diffraction

Magnetic Fe3O4 nanoparticles are prepared by the coprecipitation method and coated with starch as a surfactant. Their structural and magnetic behaviours are studied by means of X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Raman spectrum, Fourier Transform Infrared (FT-IR) as well as with a Vibrating Sample Magnetometer (VSM). The magnetic Fe3O4 nanoparticles under investigation have an average size of about 14 nm. The coated magnetic nanoparticles exhibit super-paramagnetic behaviours with a blocking temperature of about 170 K and saturation magnetisation ranging between 30 and 50 emu g−1. In addition, the results of FT-IR indicated that interactions between the Fe3O4 particles and starch layers are much improved.

Structural and magnetic properties of starch-coated magnetite nanoparticles

Magnetic nanoparticles Fe3O4 were prepared in air environment by the coprecipitation method using molar ratios of Fe2+: Fe3+ = 1: 2. The surface of magnetic nanoparticles was coated with sodium oleate as the primary layer and polyethylene glycol 6000 (PEG-6000) as the second layer. The morphology of the particles was investigated by scanning electronic microscopy (SEM). X-ray diffraction (XRD) indicated the sole existence of inverse cubic spinel phase of Fe3O4 and an average size of about 25 nm. Fourier transform infrared spectroscopy (FTIR) analysis indicated existence of two distinct surfactants on the particle surface. In addition, the results of FT-IR indicated that the coated Fe3O4 particles improved the thermal stability due to the interaction between the Fe3O4 particles and protective layers.

/pdf/preparation-and-characterization-of-magnetic-nanoparticles-1n8btt6565.pdf

Preparation and characterization of magnetic nanoparticles coated with polyethylene glycol

We have prepared polymeric drug nanoparticles by oil in water (O/W) emulsion solvent evaporation method. We used acetone as solvent for polymer and water as non-solvent. The purpose of this study is to use the emulsion solvent evaporation method in order to prepare nanoparticles and to investigate the effects of the various processing parameters to the characteristics of the nanoparticles. In this research, we use two different forms of acrylic polymers, Eudragit E100 and Eudragit RS. It was found that the size of the nanoparticles depends on different parameters such as the polymer concentration in the organic solvent, surfactant concentration and the volume ratio of oil and water phases. The morphology structure is investigated by transmission electron microscope (TEM). TEM images confirmed that the nanoparticles produced were spherical in shape and the successfully prepared nanoparticles with size 80 nm. The size distribution is measured by laser dynamic light scattering. The size distribution of the n...

Preparation and characterisation of nanoparticles containing ketoprofen and acrylic polymers prepared by emulsion solvent evaporation method

Polymeric drug nanoparticles were prepared by emulsion solvent evaporation method. In this study, prepared the polymeric drug nanoparticles consist of ketoprofen and Eudragit E 100. The morphology structure was investigated by scanning electron microscopy (SEM). The interactions between the drug and polymer were investigated by Fourier transform infrared spectroscopy (FTIR). The size distribution was measured by means of Dynamic Light Scattering. The nanoparticles have an average size of about 150 nm. The incorporation ability of drugs in the polymeric nanoparticles depended on the integration between polymer and drug as well as the glass transition temperature of the polymer.

http://iopscience.iop.org/article/10.1088/1742-6596/187/1/012047/pdf

Preparation of drug nanoparticles by emulsion evaporation method

Self-cleaning hydrophilic and hydrophobic properties of TiO2-based thin films on glass substrates have been investigated in this study. The addition of SiO2 into TiO2 can increase the wettability of films and maintain the hydrophilic state for a long time even in the dark. The contact angle of water on deposited films containing 15% SiO2 is less than 2° after 2 h of UV illumination. These TiO2–SiO2 films exhibit excellent antifogging characteristics. Meanwhile, TiO2–Al2O3 films possess high water repellent ability and the photo-induced self-cleaning can take place even in visible light. The TiO2 thin film containing 33% of Al2O3 shows a high hydrophobic state with a water contact angle of 73° after being irradiated with sunlight for 2 h. A comparison of hydrophilic TiO2–SiO2 and hydrophobic TiO2–Al2O3 films demonstrates the ability to modify the TiO2 thin film properties for self-cleaning applications.

Dang Mau Chien

Papers

Structural and magnetic properties of starch-coated magnetite nanoparticles

Preparation and characterization of magnetic nanoparticles coated with polyethylene glycol

Preparation and characterisation of nanoparticles containing ketoprofen and acrylic polymers prepared by emulsion solvent evaporation method

Preparation of drug nanoparticles by emulsion evaporation method

Characteristics modification of TiO2 thin films by doping with silica and alumina for self-cleaning application