Influence of Dextran Molecular Weight on the Physical Properties of Magnetic Nanoparticles for Hyperthermia and MRI Applications.

Oliver Strbak,Iryna Antal,Vlasta Zavisova,Martina Kubovcikova,Jan Gombos,Petra Hnilicova,Alena Jurikova,Nina Kadasova,Matus Molcan,Martina Koneracka,Dusan Dobrota,Iryna Khmara

doi:10.3390/nano10122468

Abstract

Dextran-coated magnetic nanoparticles are promising biocompatible agents in various biomedical applications, including hyperthermia and magnetic resonance imaging (MRI). However, the influence of dextran molecular weight on the physical properties of dextran-coated magnetic nanoparticles has not been described sufficiently. We synthesise magnetite nanoparticles with a dextran coating using a co-precipitation method and study their physical properties as a function of dextran molecular weight. Several different methods are used to determine the size distribution of the particles, including microscopy, dynamic light scattering, differential centrifugal sedimentation and magnetic measurements. The size of the dextran-coated particles increases with increasing dextran molecular weight. We find that the molecular weight of dextran has a significant effect on the particle size, efficiency, magnetic properties and specific absorption rate. Magnetic hyperthermia measurements show that heating is faster for dextran-coated particles with higher molecular weight. The different molecular weights of the coating also significantly affected its MRI relaxation properties, especially the transversal relaxivity r2. Linear regression analysis reveals a statistically significant dependence of r2 on the differential centrifugal sedimentation diameter. This allows the targeted preparation of dextran-coated magnetic nanoparticles with the desired MRI properties. These results will aid the development of functionalised magnetic nanoparticles for hyperthermia and MRI applications.

Highlights

Biocompatible magnetic nanoparticles (MNPs) are essential in the field of nanomedicine as they provide non-toxic systems for various biomedical applications, including targeted drug delivery, magnetic hyperthermia (MH) and magnetic resonance imaging (MRI) [1,2,3,4,5]
In addition to determining the relaxivity of the DEX-coated MNPs with various molecular weight (MW) of DEX, we focused on the possible correlation and causality of the relaxivity values on the diameter, determined by various methods: dynamic light scattering (DLS), differential centrifugal sedimentation (DCS), SEM and magnetic measurements (Figure 8D)
There was a lack of information regarding the influence of the MW of DEX coating on the physical and MRI properties of such modified MNPs

Summary

Introduction

Biocompatible magnetic nanoparticles (MNPs) are essential in the field of nanomedicine as they provide non-toxic systems for various biomedical applications, including targeted drug delivery, magnetic hyperthermia (MH) and magnetic resonance imaging (MRI) [1,2,3,4,5]. MH is a promising therapeutic method in cancer treatment and is currently attracting increasing attention [6]. It includes an artificially induced increase in temperature (up to 45 ◦C) from the heat generated by the MNPs when subjected to an alternating magnetic field (AMF) [6]. Efforts have been focused on maximising the heat generation into the surrounding environment and this can be achieved by varying the applied magnetic field intensity and frequency or by increasing the concentration of MNPs [9]. Apart from the application parameters (H and f ), the SAR depends on the magnetic component characteristics, such as particle size, distribution, shape and magnetic properties of MNPs, including coating/surfactant properties, which affect the hydrodynamic size and carrier liquid viscosity [5,12,13,14]

Methods

Results

Conclusion