Oleylamine as a beneficial agent for the synthesis of CoFe₂O₄nanoparticles with potential biomedical uses

Abstract

The multifunctional role of oleylamine (OAm) as a versatile and flexible reagent in synthesis as well as a desired surface ligand for the synthesis of CoFe2O4 nanoparticles (NPs) is described. CoFe2O4 NPs were prepared by a facile, reproducible and scalable solvothermal approach in the presence of pure OAm. By monitoring the volume of OAm, different shapes of NPs, spherical and truncated, were formed. The syntheses led to high yields of monodispersed and considerably small (9-11 nm) CoFe2O4 NPs with enhanced magnetization (M(s) = 84.7-87.5 emu g(-1)). The resulting hydrophobic CoFe2O4 NPs were easily transferred to an aqueous phase through the formation of reverse micelles between the hydrophobic chains of OAm and cetyltrimethylammonium bromide (CTAB) and transverse relaxivities (r2) were measured. The spherical NPs had a greater effect on water proton relaxivity (r2 = 553 mM(-1) s(-1)) at an applied magnetic field of 11.7 T. The NPs became fluorescent probes by exploiting the presence of the double bond of OAm in the middle of the molecule; a thiol-ene "click" reaction with the fluorophore bovine serum albumin (FITC-BSA) was achieved. The labeled/biofunctionalized CoFe2O4 NPs interacted with cancer (HeLa and A549) and non-cancer cell lines (MRC5 and dental MSCS) and cell viability was estimated. A clear difference of toxicity between the cancer and non-cancer cells was observed while low cytotoxicity in living cells was supported. Confocal laser microscopy showed that NPs entered the cell membranes and were firstly localized close to them provoking a membrane expansion and were further accumulated perinuclearly without entering the nuclei.

Influence of cobalt doping on the hyperthermic efficiency of magnetite nanoparticles

“…While for uncoated cobalt ferrite NPs a non-negligible toxicity is reported in the literature [13,14], the coating with silica or polymers strongly improves their biocompatibility [13,15,16]. However, a low residual toxicity is often still present, depending on the cellular line investigated and on the concentration of the NPs used [17,18]. Moreover, it must be noted that almost all cytotoxicity tests reported in the literature are performed at much lower NPs concentrations than that required by hyperthermia assays.…”

A Review of the Synthesis and Applications of Polymer–Nanoclay Composites

“…Heretofore, the most widely applied synthesis method was the in-situ polymerization method, where the grafted amounts of organics was adjusted and the clay interlayer spacing was controlled by changing the polymerization conditions [38]. The combination of in-situ polymerization with efficient coupling methods, including click chemistry [39], radical-mediated polymerization [40,41], tandem preparation [42], photopolymerization [38] and miniemulsion [43], has enabled effective dispersion of nanoclays in the form of individual platelets in the polymer matrix, which is a significant challenge inherent to the synthesis of polymer/nanoclay composites. All these methods have been successfully implemented for the chemical modification of clay surfaces with low molecular or polymeric grafts [44].…”

Nanoengineered thermoresponsive magnetic hydrogels for biomedical applications

“…Among the different types of MNPs, ferromagnetic, and superparamagnetic nanoparticles have been extensively investigated for biomedical applications (Figure b) . Superparamagnetic MNPs are less than 30 nm in diameter and under an AMF these MNPs produce heat due to Brownian and Néel relaxation .…”

“…The modified surface of FePt nanoparticles allows for applications in targeted drug delivery, photochemical therapy, biosensing, and imaging . Finally, cobalt‐iron (CoFe) nanoparticles are also under investigation for potential bioimaging and drug delivery applications . Overall, superparamagnetic iron‐containing nanoparticles (SPINs) are utilized in research for a wide range of biomedical applications and have potential for clinical translation due to low cell toxicity …”