Physical characterization of biomedical magnetic nanoparticles using multi-detector centrifugal field-flow fractionation

Abstract

The unique magnetic properties of magnetic nanoparticles (MNP) combined with their small size already led to numerous medical applications. Accurate determination of their magnetic properties is a key requirement enquired by users, that is impeded by the ever-present distribution of MNP sizes. Field flow fractionation (FFF) techniques may help to overcome these limitations by first separating the particles before characterization. In this study, we demonstrate the use of centrifugal FFF coupled to online detectors for fractionation, structural, and magnetic characterization of MNP. The primary goal is to establish a reproducible centrifugal FFF (CF3) method for MNP fractionation We show that CF3 has the same capability as other FFF techniques in resolving the bimodal hydrodynamic size distribution present in the commercial MNP system Resovist® but is faster and more straightforward through its technical approach.

Determining the resolution of a tracer for magnetic particle imaging by means of magnetic particle spectroscopy

“…Very promising approaches for structural analyses are separation techniques that have already been described in ref. 12 and 31 .…”

Cell Tracking by Magnetic Particle Imaging: Methodology for Labeling THP-1 Monocytes with Magnetic Nanoparticles for Cellular Imaging

“…To evaluate the MNP behavior in different biological media prior to cell contact, we performed centrifugal flow-field fractionations (CF3, Postnova Analytics GmbH, Landsberg am Lech, Germany). In CF3, the sample is transported within the main flow through a thin channel (350 µm height) [ 19 ]. A centrifugal force drives the particles towards the channel wall in a rotating disk.…”

“…A rotational speed of v rot = 4900 1/min, ddH 2 O as carrier liquid, and an MNP concentration of c (Fe) = 5 mmol/L were used for the separation. The fractions were afterwards magnetically and structurally characterized using the online detector array of CF3 consisting of an MPS (MPS-3, Bruker BioSpin, Rheinstetten, Germany), a device for dynamic light scattering (DLS) (Zetasizer NanoZS, Malvern, UK), and an ultraviolet/visible (UV/Vis) spectrophotometer (Postnova Analytics, Landsberg am Lech, Germany) [ 19 ]. The detectors are described in the following paragraphs (2.5–2.7).…”