The magnetic ferrite nanoparticles are recently in focus of modern science and biotechnology due to their unique properties, giving them a variety of possible applications, including targeted drug delivery. Colloidal ferrites are usually synthesized in a relatively simple aqueous precipitation reaction, which can be easily adapted for big-scale preparations. However, the main disadvantage of this route is the high polydispersity of the product, unsatisfactory for further practical applications. Here, we propose an efficient way of sorting the particles by size. The colloidal suspension of nanoparticles is centrifuged at increasing rotational speed and the fraction sedimented on the bottom of the tube is collected after each run. The particles’ size distribution and the efficiency of the process is estimated by agarose gel electrophoresis. Quantitatively, the mean size in each fraction is measured by Small Angle X-Ray Scattering and Powder X-Ray Diffraction.

Fig.1. Top: Powder XRD patterns of samples collected at increasing centrifugal forces. Widening of the peaks is observed.  Crystallite size calculated from PXRD peak broadening for the unsorted sample: 14 +/- .5 nm.

 Sorted particles are further subjected to chemical modifications of their surface including, in the first step, the adsorption of simple surfactant molecules and/or growth of the colloidal silica layer. Two-dimensional arrays, (on aqueous subphase, Langmuir-type) of particles grafted with oleic acid are transferred onto the solid substrate by Langmuir-Blodgett technique.  Subsequently, they were characterized by neutron and X-ray reflectivity as well as IR spectroscopy. The second step includes the covalent attachment of drug molecules (e.g., anthraquinone derivatives) to the particle surface coated with silica. Magnetic properties allow for targeted medicine delivery while silica coating prevents the heavy-metal containing core from direct contact with the organism thus providing higher biocompatibility of these carriers.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/12339 must be provided.

1. Solid-core and hollow magnetic nanostructures: synthesis, surface modifications and biological applications
2. Understanding and Controlling Curvature and Intermolecular Interactions in Biomimetic Membranes
3. Probing interfacial organization in planar lipid bilayers using tethered pyrene
4. Immobilization of molecules: From self-assembled monolayers to polymeric hollow structures
5. Probing organization and communication at layered interfaces
6. Application of ZP chemistry for the immobilization of polycyclic aromatic hydrocarbons and enzymes on gold, boron doped diamond, indium tin oxide and quartz.
7. Spectroscopic and Electrochemical Characterization of Interfacial Biomimetic Assemblies for Biosensors
8. Magnetoresistance and magnetic properties of the double perovskites