Data on iron oxide core oil-in-water nanoemulsions for atherosclerosis imaging

The data presented in this article are related to the publication entitled “Iron oxide core oil-in-water nanoemulsion as tracer for atherosclerosis MPI and MRI imaging” (Prévot et al., 2017) [1]. Herein we describe the synthesis and the characteristics of the Superparamagnetic Iron Oxide Nanoparticles (SPION) loaded inside nanoemulsions (NEs). Focus was set on obtaining SPION with narrow size distribution and close to superparamagnetic limit (20 nm) in order to reach a reasonable magnetic signal. Nanoparticles (NPs) of three different sizes were obtained (7, 11 and 18 nm) and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), diffuse reflectance infrared Fourier transform (DRIFT) and thermogravimetric analysis (TGA). SPION were coated with oleic acid (OA) in order to load them inside the oily core of NEs droplets. SPION loaded NEs were magnetically sorted using MACS® MS Column (Miltenyi Biotec) and iron quantification was performed by UV-spectrometry measurements.


a b s t r a c t
The data presented in this article are related to the publication entitled "Iron oxide core oil-in-water nanoemulsion as tracer for atherosclerosis MPI and MRI imaging" (Prévot et al., 2017) [1]. Herein we describe the synthesis and the characteristics of the Superparamagnetic Iron Oxide Nanoparticles (SPION) loaded inside nanoemulsions (NEs). Focus was set on obtaining SPION with narrow size distribution and close to superparamagnetic limit (20 nm) in order to reach a reasonable magnetic signal. Nanoparticles (NPs) of three different sizes were obtained (7, 11 and 18 nm) and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), diffuse reflectance infrared Fourier transform (DRIFT) and thermogravimetric analysis (TGA). SPION were coated with oleic acid (OA) in order to load them inside the oily core of NEs droplets. SPION loaded NEs were magnetically sorted using MACS® MS Column

Bordeaux, France
Data accessibility The data is provided with this article

Value of the data
The data presented in this paper describe two synthesis processes in order to obtain SPION from 3 different sizes 7, 11 and 18 nm.
SPION physico-chemical properties were characterized by TEM, XRD, DRIFT, TGA and VSM. NEs magnetic sorting process using MACS® MS Column (Miltenyi Biotec) and iron quantification data are also described.
These data will be helpful for the scientific community that work with magnetic nanosystems.

Data
The dataset of this articles provides information about the engineering of hydrophobic SPION and their loading inside NEs for imaging purpose [1]. Figs. 1 and 2 and Table 1 display the size characteristics of the NPs obtained by TEM and XRD. Fig. 3 displays the magnetic behavior of the 3 different NPs obtained by VSM. NPs coating was assessed by DRIFT and TGA analysis (Fig. 4). Fig. 5 shows the iron quantification of NEs before and after magnetic sorting.

Magnetic nanoparticles synthesis
Maghemite NPs of 7 nm diameter were synthesized by alkaline coprecipitation of ferrous and ferric salts as previously described [2]. NPs of 11 nm were obtained using size sorting procedure  Table 1.  Table 1.

Table 1
Values of average sizes (D), standard deviations (σ) obtained by TEM and crystallite sizes by XRD analysis. The average crystallite sizes were obtained from the EVA software after assessment of the integral width of the most intense peak (311) and the   according to Sandre and al. [3]. Hydrophobization of these NPs was performed by complexation of OA on the SPION surface according to the procedure described by Van Ewijk et al. [4]. For 18 nm sized NPs, the synthesis derived from a slightly modified procedure previously described by Sun et al. [5] and hydrophobic NPs are directly obtained.

Characterizations of NPs
TEM micrographs were performed with a Philips CM120 microscope operating at 120 kV and captured with Ultra scan USC1000 2k×2k camera. Assessments of NPs sizes were performed with the Digital Micrograph software from Gatan on more than 300 NPs.
XRD on dried powders were performed with a PANalytical X'pert PRO MPD diffractometer in Bragg-Brentano (θ-θ) geometry Cu Kα radiation (λ ¼1.5418 Å) to check the crystallographic structure and to assess the crystallite size (size of the coherent domains of diffraction). Magnetic measurements were performed with a VSM MicroSence FCM-10 at 290 K for a field H varying to 75000 Oe. DRIFT spectroscopy was performed with a Bruker IFS Equinox 55 FTIR spectrometer (signal averaging 32 scans at a resolution of 4 cm -1 ) equipped by a selector Graseby Specac diffuse reflection cell (Eurolabo, France).
TGA were assessed using a Tag2400 thermobalance from Setaram (Caluire-et-Cuire, France). TGA measurements were effected by applying a first temperature cycle from 25°C to 650°C by increasing heat of 2°C/min under O 2 .

Iron quantification
Iron was quantified by UV-spectrometry measurements. Samples were prepared following this procedure: ethanol was used to break the emulsion. After 10 min centrifugation at 14,000 g, precipitates were washed with ethanol and centrifuged again. Then the precipitate was dissolved into HCl (2%)/HCOOH, in order to dissolve the maghemite NPs into Fe 3 þ ions. These ions react with KSCN to produce a red compound allowing the iron concentration determination by spectrometry measurements at 466 nm. Geoffrey Prévot is a recipient of a Ph.D. fellowship from the French Ministry of Education Research and Technology. TRAIL program seeks to facilitate interdisciplinary, collaborative basic and clinical research in image based diagnostics and novel bio-compatible technologies for evaluating treatments, interventions and drug delivery strategies.

Transparency document. Supporting information
Transparency data associated with this article can be found in the online version at http://dx.doi. org/10.1016/j.dib.2017.10.059.