Characterization of physicochemical and colloidal properties of hydrogel chitosan-coated iron-oxide nanoparticles for cancer therapy

Enhancing Physicochemical Properties and Biocompatibility of Hollow Porous Iron Oxide Nanoparticles through Polymer-Based Surface Modifications

In this study, we synthesized hollow porous iron oxide nanoparticles (HPIONPs) with surface modifications using polymers, specifically chitosan (Chi), polyethylene glycol (PEG), and alginate (Alg), to improve colloidal stability and biocompatibility. For colloidal stability, Alg-coated HPIONPs maintained size stability up to 24 h, with only an 18% increase, while Chi, PEG, and uncoated HPIONPs showed larger size increases ranging from 64 to 140%. The biocompatibility of polymer-coated HPIONPs was evaluated by assessing their cell viability, genotoxicity, and hemocompatibility. Across tested concentrations from 6.25 to 100 μg/mL, both uncoated and polymer-coated HPIONPs showed minimal cytotoxicity against three normal cell lines: RAW264.7, 3T3-L1, and MCF10A, with cell viability exceeding 80% at the highest concentration. Notably, polymer-coated HPIONPs exhibited nongenotoxicity based on the micronucleus assay and showed hemocompatibility, with only 2-3% hemolysis in mouse blood, in contrast to uncoated HPIONPs which exhibited 4-5%. Furthermore, we evaluated the cytotoxicity of HPIONPs on MDA-MB-231 breast cancer cells after a 2 h exposure to a stationary magnetic field, and the results showed the highest cell death of 38 and 29% when treated with uncoated and polymer-coated HPIONPs at 100 μg/mL, respectively. This phenomenon is attributed to iron catalyzing the Fenton and Haber-Weiss reactions, leading to reactive oxygen species (ROS)-dependent cell death (r ≥ 0.98). In conclusion, the hydrothermal synthesis and subsequent surface modification of HPIONPs with polymers showed improved colloidal stability, nongenotoxicity, and hemocompatibility compared to uncoated HPIONPs while maintaining closely similar levels of cytotoxicity against both normal and cancer cells. This research has paved the way for further exploration of polymer coatings to enhance the overall performance and safety profile of magnetic nanoparticles in delivering anticancer drugs.

Screen-printed disposable electrodes using graphite-polyurethane composites modified with magnetite and chitosan-coated magnetite nanoparticles for voltammetric epinephrine sensing: a comparative study

Disposable screen-printed electrodes based on the use of graphite-polyurethane composites modified with magnetite nanoparticles (MNP-SPE) or chitosan-coated magnetite nanoparticles (CHMNP-SPE) are described. The MNP and CHMNP were synthetized and comparatively characterized by TEM, XRD, FTIR, and TGA/DTG. The MNP-SPE and CHMNP-SPE were characterized by SEM and EDX. After optimization of the MNP percentage in MNP-SPE, the materials were electrochemically characterized by cyclic voltammetry, EIS, and chronocoulometry. The electrodes were tested for their performance towards sensing of epinephrine (EP). The CHMNP-SPE is found to have better electrochemical responses in comparison to the MNP-SPE. This is assumed to be due to the chitosan coating which also protects the MNPs from oxidation under air and at different applied potential fields. The performances of the MNP-SPE and CHMNP-SPE were studied by DPV after optimization of equilibration time and DPV parameters. Response is linear in the 0.1-0.8 μM EP concentration range, at 0.03 V (vs. pseudo-Ag/AgCl), and the detection limit is 25 nM for the MNP-SPE. The linear response for the CHMNP-SPE was 0.1-0.6 μM, at 0.0 V (vs. pseudo-Ag/AgCl), and a LOD of 14 nM was achieved. The devices were used for the quantification of EP in synthetic urine and in cerebrospinal synthetic fluids. Recoveries from spiked samples are in the 95.6-102.2% range for the CHMNP-SPE and in the 98.3-109% range for MNP-SPE. The stability of the respective sensors was investigated and compared over a period of 5 months. The EP peak currents were found to decrease by only 4% for the CHMNP-SPE, while the MNP-SPE lost 23% of its EP peak current. Accordingly, the CHMNP-SPE was chosen as the most stable and sensitive sensor for EP. Graphical abstract Schematic figure of modification of a graphite-polyurethane screen-printed composite electrode with magnetite nanoparticles (MNPs) and chitosan-coated magnetite nanoparticles (CHMNPs) for the voltammetric determination of epinephrine (EP). Improved response of CHMNP-SPE (black voltammogram) in comparison to MNP-SPE (red voltammogram) was attributed to the protection of MNP from oxidation.

Magnetic Materials and Systems: Domain Structure Visualization and Other Characterization Techniques for the Application in the Materials Science and Biomedicine

Magnetic structures have attracted a great interest due to their multiple applications, from physics to biomedicine. Several techniques are currently employed to investigate magnetic characteristics and other physicochemical properties of magnetic structures. The major objective of this review is to summarize the current knowledge on the usage, advances, advantages, and disadvantages of a large number of techniques that are currently available to characterize magnetic systems. The present review, aiming at helping in the choice of the most suitable method as appropriate, is divided into three sections dedicated to characterization techniques. Firstly, the magnetism and magnetization (hysteresis) techniques are introduced. Secondly, the visualization methods of the domain structures by means of different probes are illustrated. Lastly, the characterization of magnetic nanosystems in view of possible biomedical applications is discussed, including the exploitation of magnetism in imaging for cell tracking/visualization of pathological alterations in living systems (mainly by magnetic resonance imaging, MRI).

Environmentally benign pH-responsive cytidine-5′-monophosphate molecule-mediated akaganeite (5′-CMP-β-FeOOH) soft supramolecular hydrogels induced by the puckering of ribose sugar with efficient loading/release capabilities

A novel synthetic protocol for environmentally benign 5′-CMP-β-FeOOH soft hydrogels exhibiting a rapid pH-responsive reversible sol–gel transition, efficient adsorption and slow release capabilities is reported.

The Toxicity Assessment of Iron Oxide (Fe₃O₄) Nanoparticles on Physical and Biochemical Quality of Rainbow Trout Spermatozoon

The aim of this study was to evaluate the in vitro effect of different doses (50, 100, 200, 400, and 800 mg/L) of Fe₃O₄ nanoparticles (NPs) at 4 °C for 24 h on the kinematics of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) spermatozoon. Firstly, Fe₃O₄ NPs were prepared at about 30 nm from Iron (III) chloride, Iron (II) chloride, and NH₃ via a co-precipitation synthesis technique. Then, the prepared Fe₃O₄ NPs were characterized by different instrumental techniques for their chemical structure, purity, morphology, surface properties, and thermal behavior. The size, microstructure, and morphology of the prepared Fe₃O₄ NPs were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) spectroscopy, and scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS). The thermal properties of the Fe₃O₄ NPs were determined with thermogravimetric analysis (TGA), differential thermal analysis (DTA), and differential scanning calorimeter (DSC) analysis techniques. According to our results, there were statistically significant (p < 0.05) decreases in the velocities of spermatozoon after treatment with 400 mg/L Fe₃O₄ NPs. The superoxide dismutase (SOD) and catalase (CAT) activities were significant (p < 0.05) decrease after 100 mg/L in after exposure to Fe₃O₄ NPs in 24 h. As the doses of Fe₃O₄ NPs increases, the level of malondialdehyde (MDA) and total glutathione (tGSH) significantly (p < 0.05) increased at doses of 400 and 800 mg/L.