Rapid Sonochemical Approach Produces Functionalized Fe₃O₄Nanoparticles with Excellent Magnetic, Colloidal, and Relaxivity Properties for MRI Application

Abstract

Functionalized Fe3O4 nanoparticles (NPs) have emerged as a promising contrast agent for magnetic resonance imaging (MRI). Their synthesis and functionalization methodology strongly affect their performance in vivo. The methodology most used in the literature for the synthesis of Fe3O4 NPs is thermal decomposition, which has proven to be time-consuming, expensive, and laborious, as it requires further ligand exchange strategies to transfer the as-synthesized nanoparticles from organic to aqueous solvents. This work describes a rapid and facile sonochemical methodology to synthesize and functionalize Fe3O4 NPs with excellent physicochemical properties for MRI. This sonochemistry approach was used to produce, in 12 min, Fe3O4 NPs functionalized with polysodium acrylate (PAANa), trisodium citrate (CIT), branched polyethylenimine (BPEI), and sodium oleate. X-ray diffraction and transmission electron microscopy demonstrated that the NPs were composed of a single inverse spinel phase with an average diameter of 9–11 nm and a narrow size distribution. Mössbauer spectroscopy and magnetic measurements confirmed that the obtained NPs were transitioning to the superparamagnetic regime and possessed excellent magnetization saturation values (59–77 emu/g). Fourier transform infrared spectroscopy proved that the sonochemistry approach provided conditions that induced a strong interaction between Fe3O4 and the coating agents. Furthermore, dynamic light-scattering experiments evidenced that samples coated with PAANa, CIT, and BPEI possess colloidal stability in aqueous solvents. Emphasis must be placed on PAANa-coated NPs, which also presented remarkable colloidal stability under simulated physiological conditions. Finally, the obtained NPs exhibited great potential to be applied as an MRI contrast agent. The transverse relaxivity values of the NPs synthesized in this work (277–439 mM–1 s–1) were greater than those of commercial NPs and those prepared using other methodologies. Therefore, this work represents significant progress in the preparation of Fe3O4 NPs, providing a method to prepare high-quality materials in a rapid, cost-effective, and facile manner.

Chitosan-magnetite nanocomposite as a sensing platform to bendiocarb determination

“…One can be observe a presence of two distinct morphology: rods and spherical. It is interesting to note that the nanorod morphology is not present in the previous work [47,[58][59][60]. Thus, this result suggesting that the increase in the ultrasound time may lead to the formation of nanorods of magnetite coated with chitosan.…”

“…Li et al [58]s h o w e dt h a tt h i s changes occur when the time is increasing of 5 min to 30 min. Furthermore, Neto et al [59] have synthesized magnetite ferrofluid with different polymers in a time greater than that used in this work and the nanoparticles do not present nanorods morphology. It is well-known that capping agent can orient the preferential growth of ac r y s t a ld u et ot h ec h a n g eo ft h ef r e ee n e r g yo fd i f f e rent facets [60].…”

Orthogonal Clickable Iron Oxide Nanoparticle Platform for Targeting, Imaging, and On‐Demand Release

“…The presenceo fp yrene after the reaction was confirmedb yU V/Vis spectroscopy,w hich showed absorption bands from the maleimide moiety at l = 261 and 210 nm and those from the pyrene ligand at l = 343, 327, 313, and 234 nm ( Figure 5, green). An increment in the organic content of 22 wt %w as calculated from TGA measurements, with one additional weightl oss feature at 400 8C, in comparison with that of Maleimide-Alkyne-Fe 3…”

“…Naked Fe 3 O 4 NPs (27 mg) were suspended in dry toluene (1.4 mL) and subjected to sonication for 5min. Maleimide isocyanate 1 (24 mg, 0.11mmol) and alkyne isocyanate 2 (19 mg, 0.11mmol) were added to the suspension and the mixture was subjected to sonication at 60 8Cf or 4h.T hen, the IONs were isolated magnetically and washed with toluene (4 )t oy ield Maleimide-Alkyne-Fe 3…”

“…The magnetic responseo fI ONs can be exploited for detection by magnetic resonance imaging (MRI) because IONs can be designedt oc reate different contrasts. [3,4] Similarly,t he magnetic properties can be used to label stem cells for cell-tracking applications, [5] to guide the nanomaterials to the desiredl ocation through the application of magnetic fields, [6] to increase temperature by magnetich yperthermia, [7,8] or to release ad rug on command through triggeredh eat production. [9][10][11][12] Therefore, magneticI ONs can act as theranostic probes, which pro-vide therapy and diagnosis simultaneously.…”