Engineered Inorganic/Organic-Core/Shell Magnetic Fe_xO_y Nanoparticles with Oleic Acid and/or Oleylamine As Capping Agents

Abstract

Magnetic nanoparticles with tailored surface chemistry are widely used for a number of different in vivo applications, ranging from tissue repair and magnetic cell separation through to cancer-hyperthermia, drug delivery and magnetic resonance imaging contrast enhancement. A major requirement for all these biomedical applications is that these nanoparticles must have high magnetization values and sizes smaller than 100 nm with a narrow particle size distribution. Thus nanoparticles must have uniform physical and chemical properties. For these applications, a tailored surface coating/shell needs to be engineered, which has to be non-toxic, biocompatible and make allowance for targetable drug delivery with particle localization in a targeted area. Most work in this field has been done on improving the biocompatibility of the nanoparticles. Only a few scientific investigations have been carried out on improving the quality of magnetic nanoparticles with specific focus on the nanoparticle's surface chemistry, size distribution and shape (which directly influences the magnetic properties). All these particles also need to be properly characterized in order to get a protocol for the quality control of these particles, the nature of the surface coatings and their subsequent geometric arrangement. This will ultimately determine the overall size of the colloids and also plays a significant role in biokinetics and biodistribution of nanoparticles in the body. This review highlights recent advances in the synthetic chemistry, magnetic characterization and biological applications of inorganic/organic - core/shell FexOy based magnetic nanoparticles with specific focus on using the two popular surfactants for producing MNPs namely oleic acid and/or oleylamine as capping agents. Although the main nano-magnets under discussion are magnetite (Fe3O4) nanoparticles, maghemite (γ-Fe2O3) is also briefly mentioned.

Unveiling the Structure and Reactivity of Fatty-Acid Based (Nano)materials Thanks to Efficient and Scalable 17O and 18O-Isotopic Labeling Schemes

“…Oleic acid being one of the main surfactant molecules involved in the synthesis of metal and metal oxide nanoparticles, − the obvious next step was to show how using 17 O-enriched species can help shed light on their mode of attachment and reactivity at the surface of NPs. Here, we set our focus on functionalized ZnO NPs.…”

Hybrid nanomaterial: biocolloidals

“…One of the widely employed types of nanomaterials with diameters between 1 and 100 nm are iron oxide NPs (IONPs). Much attention was drawn to their significant features, which make IONPs very suitable for potential technologic applications in materials engineering and biological sciences (Griesser et al, 2002;Harris, 2004;Fudouzi and Sawada, 2006;Gioux et al, 2010;Gabudean et al, 2012;Giorgetti et al, 2012;Frank et al, 2013;Garg et al, 2013;Gatto et al, 2013;Hasany et al, 2013;Ghosh and Collie, 2014;Gonella and Dai, 2014;Hashemizadeh and Huyeh, 2014;Hassan and Singh, 2014;Gui et al, 2015;Guisbiers et al, 2015;Harris et al, 2015;Helmbrecht et al, 2015;Garg, 2016). Since they are relatively nontoxic to human organs, magnetite and maghemite are selected to be used in biomedical applications.…”

“…An interesting alternative method is based on a precoated surface with a thin gold layer for functionalizing IONPs. By a variety of methods, the IO-core Au-shell NP (IONP@ Au) systems have been improved (Kiatkamjornwong et al, 2002;Kim et al, 2011;Harris et al, 2015). Most techniques are achieved by the crystallization of Au grains over an IO nanocrystal and gold plating based on electrolysis.…”

“…Recent advances for colloidal particles have enabled the synthesis of highly monodispersed colloidal particles with biomolecules to obtain more functional hybrid nanoscale materials. To utilize the unique properties of nanomaterials, these advanced methods have always been examined for a biological setting (Hayward et al, 2000;Joannopoulos et al, 2011;Im et al, 2011;Hasany et al, 2013;Han et al, 2014;Hashemizadeh and Huyeh, 2014;Hassan and Singh, 2014;Kumar et al, 2014;Gui et al, 2015;Guisbiers et al, 2015;Harris et al, 2015;Rodio et al, 2016).…”

Preparation of Large-Size, Superparamagnetic, and Highly Magnetic Fe3O4@PDA Core–Shell Submicrosphere-Supported Nano-Palladium Catalyst and Its Application to Aldehyde Preparation through Oxidative Dehydrogenation of Benzyl Alcohols

“…However, single Fe 3 O 4 nanospheres will usually experience an agglomeration phenomenon, which hinders the catalytic reaction. Hence, substances such as SiO 2 [10,11], dopamine [12,13,14,15], and surfactant [16,17,18] are usually used to wrap Fe 3 O 4 so that it becomes uniformly dispersed, achieving favorable hydrophilic interactions. This type of Fe 3 O 4 with a core–shell structure has enormous application potential in various fields, including bioseparation [19,20], diagnostic analysis [21,22], molecular imprinting [23], and battery energy storage [24].…”