The impact of polymer coatings on magnetite nanoparticles performance as MRI contrast agents: a comparative study

Abstract

BackgroundSuperparamagnetic iron oxide nanoparticles (SPIONs) are the most commonly used negative MRI contrast agent which affect the transverse (T2) relaxation time. The aim of the present study was to investigate the impact of various polymeric coatings on the performance of magnetite nanoparticles as MRI contrast agents.MethodsFerrofluids based on magnetite (Fe3O4) nanoparticles (SPIONs) were synthesized via chemical co-precipitation method and coated with different biocompatible polymer coatings including mPEG-PCL, chitosan and dextran.ResultsThe bonding status of different polymers on the surface of the magnetite nanoparticles was confirmed by the Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The vibrating sample magnetometer (VSM) analysis confirmed the superparamagnetic behavior of all synthesized nanoparticles. The field–emission scanning electron microscopy (FE-SEM) indicated the formation of quasi-spherical nanostructures with the final average particle size of 12–55 nm depending on the type of polymer coating, and X-ray diffraction (XRD) determined inverse spinel structure of magnetite nanoparticles. The ferrofluids demonstrated sufficient colloidal stability in deionized water with the zeta potentials of −24.2, −16.9, +31.6 and −21 mV for the naked SPIONs, and for dextran, chitosan and mPEG-PCL coated SPIONs, respectively. Finally, the magnetic relaxivities of water based ferrofluids were measured on a 1.5T clinical MRI instrument. The r2/r1 value was calculated to be 17.21, 19.42 and 20.71 for the dextran, chitosan and mPEG-PCL coated SPIONs, respectively.ConclusionsThe findings demonstrated that the value of r2/r1 ratio of mPEG-PCL modified SPIONs is higher than that of some commercial contrast agents. Therefore, it can be considered as a promising candidate for T2 MRI contrast agent.

Intraarterial route increases the risk of cerebral lesions after mesenchymal cell administration in animal model of ischemia

“…The TGA spectrum (Fig. 1D) showed two peaks, corresponding to mass losses at approximately 280 °C and 322 °C, in the range of dextran decomposition temperature (150–380 °C)27, demonstrating that about 66 wt% of the D-MNPs can be attributed to dextran. The FTIR spectrum (Fig.…”

High impact of in situ dextran coating on biocompatibility, stability and magnetic properties of iron oxide nanoparticles

“…However, the presence of dextran due to its amorphous structure and also its effect on size reduction of the samples A and B causes to broaden observed peaks in XRD pattern of the dextran coated NPs [23]. In addition, the average crystallite size (D) is calculated by Scherrer's equation:…”

“…In fact, fluctuations of magnetization in easy directions minimize the magnetic interactions between NPs in colloidal suspension and consequently by improving dispersibility and chemical stability of nanoparticles, reduce the risk of embolism in blood vessels [6,[15][16][17]. For this reason, recently, ferrofluids based on superparamagnetic iron oxide NPs have been used as one of the most widely agents in theranostic (therapeutic and diagnostic) applications such as magnetic fluid hyperthermia [18][19][20], targeted drug delivery [21,22], magnetic resonance imaging (MRI) [23][24][25][26][27], gene therapy [28], magnetic particle imaging [29], cell labelling [30], immunoassay [31] and DNA detection [32].…”

<p>Core–Shell Imidazoline–Functionalized Mesoporous Silica Superparamagnetic Hybrid Nanoparticles as a Potential Theranostic Agent for Controlled Delivery of Platinum(II) Compound</p>

“…T 1 and T 2 relaxivity of MMSN-Imi were determined to be 5.89 and 144.88 m/Mᐧs −1 (Figure 9, B and C, respectively); therefore, the r 2 :r 1 ratio was calculated as 24.59, consistent with other reports on F 3 O 4 -coated nanoparticles. 71,72 Conclusion A novel theranostic platform was developed based on an Imifunctionalized magnetic mesoporous nanocarrier for Cis-Pt delivery. These particles provided unique advantages, such as high magnetism saturation (53 emu/g), high drug loading (~30% w:), and sustained and pH-triggered release of Cis-Pt without any burst, and are suitable for drug-targeting purposes.…”