arXiv subjects

Bahareh Rezaei

Publications and source records attributed to Bahareh Rezaei.

4 recordsLinked to original sources

arXiv2026

Shape- and Cation-Engineered Ferrite Nanoparticles for Enhanced Theranostic Performance in Ovarian Cancer Tumor-Mimicking Phantom

Magnetic hyperthermia integrated with magnetic resonance imaging (MRI) requires nanoparticles that combine strong heating, T2 contrast, and hemocompatibility after systemic administration. Here, we prepared citrate-stabilized ferrite nanoparticles (Fe3O4, Co0.6Fe2.4O4, Zn0.3Fe2.7O4, and Zn0.35Mn0.25Fe2.4O4) in spherical (8-10.5 nm) and quasi-cubic (9-12.5 nm) forms, along with 35 nm Fe3O4 cubes. By coupling morphology engineering with spinel-lattice cation substitution, we tuned saturation magnetization, coercivity, T2-weighted signal attenuation, and heat dissipation in ovarian tumor-mimicking phantoms under clinically compatible alternating magnetic fields. The 35 nm Fe3O4 cube and quasi-cubic Zn0.35Mn0.25Fe2.4O4 generated the highest phantom temperature rises, whereas smaller spherical particles produced softer heating. All formulations were cytocompatible in SKOV3 cells, with >96% viability at 24 h. However, hemocompatibility distinguished the leading candidates: 35 nm Fe3O4 cubes induced red blood cell deformation despite minimal hemolysis, while 9 nm quasi-cubic Zn0.35Mn0.25Fe2.4O4 showed no change versus PBS up to 1,000 μg mL-1. Perfusable GelMA models under physiological flow further confirmed biocompatibility. MRI phantoms showed that Fe3O4 cubes produced extended signal voids that may obscure boundaries. Overall, 9.5 nm quasi-cubic Zn0.35Mn0.25Fe2.4O4 is the leading intravenous candidate, combining strong heating, T2 contrast, and hemocompatibility, whereas large Fe3O4 cubes are better suited for localized intratumoral hyperthermia.

physics.app-ph↗

arXiv2026

Magnetic Particle Spectroscopy for Detecting Cell-Associated Zinc Ferrite Nanoparticles and Probing Their Relaxation Dynamics

Magnetic particle spectroscopy (MPS) enables sensitive detection of magnetic nanoparticles (MNPs) and characterization of their dynamic magnetization through higher-order harmonics. Here, we synthesized citrate-functionalized, 30 nm cubic Zn0.4Fe2.6O4 (ZFO) MNPs and investigated their association with SKOV3 ovarian cancer cells using MPS. The ZFO MNPs exhibited a crystalline spinel structure, a mean hydrodynamic diameter of 39.4 nm, strong room-temperature magnetization, low coercivity, and citrate-associated surface functional groups. Live/Dead imaging indicated good cytocompatibility after 24 h exposure at concentrations up to 0.5 mg/mL, while bright-field microscopy showed concentration-dependent cell-associated nanoparticle accumulation. Two MPS drive fields were compared using ZFO MNPs dispersed in DI water and agar as relatively unrestricted and strongly confined reference states. The 7.75 kHz, 20 mT condition retained more higher-order harmonics than 11.37 kHz and 10 mT and produced a larger and order-dependent spectral separation between the two states; it was therefore selected for the cellular measurements. After ZFO exposure and removal of unbound nanoparticles, MPS detected cell-associated MNPs in samples containing 0.1, 1, and 2x10^6 SKOV3 cells. The 3rd-, 5th-, and 7th-harmonic amplitudes increased proportionally with cell number, with power-law exponents of 1.03-1.09. We also report that most normalized harmonic ratios from the 1- and 2x10^6-cell samples fell between the water and agar references, indicating partial restriction of Brownian rotation in the cellular environment. These findings demonstrate that MPS can detect cell-associated MNPs while providing complementary spectral information about their ensemble-averaged physical confinement, supporting its application in magnetic cell labeling and cell-tracking studies.

physics.app-ph↗

arXiv2023

Synthesis and characterization of PEG-coated Zn$_{0.3}$Mn$_x$Fe$_{2.7-x}$O$_4$ nanoparticles as the dual T1/T2-weighted MRI contrast agent

Super-paramagnetic nanoparticles (NPs) have been widely explored as magnetic resonance imaging (MRI) contrast agents because of a combination of favorable magnetic properties, biocompability and ease of fabrication. MRI using traditional T1- or T2-weighted single mode contrast-enhanced techniques may yield inaccurate imaging results. In the present work, a T1/T2 dual mode contrast agent based on the super-paramagnetic zinc-manganese ferrite (Zn$_{0.3}$Mn$_x$Fe$_{2.7-x}$O$_4$, x= 0, 0.25, 0.75 and 1) NPs with small core size and a hydrophilic PEG surface coating is reported. The TEM, TGA and FTIR results confirmed the formation of a uniform coating on the NPs surface. The MRI analysis revealed that the Zn$_{0.3}$Mn$_{0.5}$Fe$_{2.2}$O$_4$ NPs had the maximum image contrast compared to other zinc-manganese ferrite samples. Cell viability evaluations revealed that the coated and uncoated particles did not inhibit cell growth pattern. The present PEG-coated Zn$_{0.3}$Mn$_{0.5}$Fe$_{2.2}$O$_4$ NPs can be utilized as a suitable T1/T2-weighted MRI contrast agent for better diagnostic of abnormalities in the organs or tissues.

cond-mat.mtrl-sci↗

arXiv2023

Investigation the effect of pH and reducing agent concentration on the structural properties of zinc-substitution magnetite nanoparticles

Today, spinel ferrite nanoparticles are widely used in the medical field for cancer treatment, drug delivery, and magnetic resonance imaging contrast agent due to their superior magnetic properties and biocompatibility. Due to the strong dependence of magnetic properties on morphology and other structural aspects, the magnetic properties of these nanoparticles depend on their manufacturing process. One of the goals of the researchers is to improve the magnetic properties of these nanoparticles by substituting elements such as manganese, cobalt, zinc, nickel, magnesium and iron. In this research, first, magnetic Zn0.3Fe0.6O4 nanoparticles were synthesized by hydrothermal method in the presence of citric acid as a reducing agent. In order to reduce the amount of impurity and obtain the pure spinel phase and reduce the size of magnetic nanoparticles, the hydrothermal process was carried out in the presence of different concentrations of the reducing agent and pH level of the medium. The structural investigations of the resulting nanoparticles were carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that in order to obtain pure and single-phase spinel nanoparticles with appropriate particle size and size distribution, it is necessary to control the concentration of reducing agent and pH.

cond-mat.mtrl-sci↗