Synthesis and cytotoxicity study of magnesium ferrite-gold core-shell nanoparticles

Photocatalytic, antimicrobial and antibiofilm activities of MgFe2O4 magnetic nanoparticles

This study reports the antibacterial and antibiofilm activities of Magnesium ferrite nanoparticles (MgFe2O4) against gram-positive and gram-negative bacteria. The photocatalytic degradation of Carbol Fuchsin (CF) dye (a class of dyestuffs that are resistant to biodegradation) under the influence of UV-light irradiation is also studied. The crystalline magnesium ferrite (MgFe2O4) nanoparticles were synthesized using the co-precipitation method. The morphology of the resulting nanocomposite was examined using scanning electron microscopy (SEM), while transmission electron microscopy (TEM) was employed for further characterization of particle morphology and size. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were utilized to analyze the crystalline structure, chemical composition, and surface area, respectively. Optical properties were evaluated using UV-Vis spectroscopy. The UV-assisted photocatalytic performance of MgFe2O4 nanoparticles was assessed by studying the decolorization of Carbol fuchsin (CF) azo dye. The crystallite size of the MgFe2O4 nanoparticles at the (311) plane, the most prominent peak, was determined to be 28.5 nm. The photocatalytic degradation of 10 ppm CF using 15 mg of MgFe2O4 nanoparticles resulted in a significant 96% reduction after 135 min at ambient temperature (25 °C) and a pH value of 9. Additionally, MgFe2O4 nanoparticles exhibited potent antibacterial activity against E. coli and S. aureus in a dose dependent manner with maximum utilized concentration of 30 µg/ml. Specifically, MgFe2O4 nanoparticles demonstrated substantial antibacterial activity via disk diffusion and microbroth dilution tests with zones of inhibition and minimum inhibitory concentrations (MIC) for E. coli (26.0 mm, 1.25 µg/ml) and S. aureus (23.0 mm, 2.5 µg/ml), respectively. Moreover, 10.0 µg/ml of MgFe2O4 nanoparticles elicited marked percent reduction in biofilm formation by E. coli (89%) followed by S. aureus (78.5%) after treatment. In conclusion, MgFe2O4 nanoparticles demonstrated efficient dye removal capabilities along with significant antimicrobial and antibiofilm activity against gram-positive and gram-negative bacterial strains suggesting their potential as promising antimicrobial and detoxifying agents.

Surface Deposition of Magnesium Ferrite-Based Supports with Bimetallic Gold/Silver Nanoparticles for the Catalytic Reduction of Nitroaromatics

Surface deposition of magnesium ferrite nanoparticles (MgFe2O4 NPs) with bimetallic gold/silver (Au/Ag) nanoparticles was conducted using the seed-mediated growth method to obtain magnetic-metallic composite catalysts for use in the catalytic reduction of nitroaromatics. Two types of amine-functionalized MgFe2O4 and MgFe2O4@SiO2 NPs were used as magnetic supports for the surface deposition process. The combination of several characterization analyses (i.e., XRD, XPS, TEM, SEM, EDS, and VSM) confirmed the successful syntheses of the MgFe2O4/Au/Ag and MgFe2O4@SiO2/Au/Ag NPs. The catalytic reduction of 4-nitrophenol using sodium borohydride as a reducing agent revealed that the reaction was completed within 2 min by using MgFe2O4/Au/Ag and MgFe2O4@SiO2/Au/Ag NPs as catalysts. The appearance rate constant of the MgFe2O4/Au/Ag NPs was slightly higher than that of the MgFe2O4@SiO2/Au/Ag NPs. In terms of reusability, high conversion (>80%) of the reduction of 4-nitrophenol was still obtained after 7 and 10 consecutive cycles for the MgFe2O4/Au/Ag and MgFe2O4@SiO2/Au/Ag catalysts, respectively. Interestingly, these two catalysts exhibited the highly catalytic conversion of the chosen nitroaromatic derivatives (i.e., 4-nitrobenzaldehyde and 4-nitroaniline). On the whole, the MgFe2O4/Au/Ag and MgFe2O4@SiO2/Au/Ag NPs could be utilized as suitable and sustainable catalysts for the catalytic reduction of nitroaromatics due to several desirable features (i.e., high activity, facile and rapid separation by a magnet, and good reusability).

Biosynthesis, characterization, magnetic hyperthermia, and in vitro toxicity evaluation of quercetin-loaded magnetoliposome lipid bilayer hybrid system on MCF-7 breast cancer

Novel biocompatible and effective hyperthermia (HT) treatment materials for breast cancer therapeutic have recently attracting researchers, because of their effective ablation of cancer cells and negligible damage to healthy cells. Magnetoliposome (MLs) have numerous possibilities for utilize in cancer treatment, including smart drug delivery (SDD) mediated through alternating magnetic fields (AMF). In this work, magnesium ferrite (MgFe2O4) encapsulated with liposomes lipid bilayer (MLs), Quercetin (Q)-loaded MgFe2O4@Liposomes (Q-MLs) nano-hybrid system were successfully synthesized for magnetic hyperthermia (MHT) and SDD applications. The hybrid system was well-investigated by different techniques using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), Energy dispersive X-ray (EDX), Vibrating sample magnetometer (VSM), Transmission electron microscope (TEM), and Zeta Potential (ZP). The characterization results confirmed the improving quercetin-loading on the MLs surface. TEM analysis indicated the synthesized MgFe2O4, MLs, and Q-MLs were spherical with an average size of 23.7, 35.5, and 329.5 nm, respectively. The VSM results revealed that the MgFe2O4 exhibit excellent and effective saturation magnetization (MS) (40.5 emu/g). Quercetin drug loading and entrapment efficiency were found to be equal to 2.1 ± 0.1% and 42.3 ± 2.2%, respectively. The in-vitro Q release from Q-loaded MLs was found 40.2% at pH 5.1 and 69.87% at pH 7.4, verifying the Q-loading pH sensitivity. The MLs and Q-MLs hybrid system as MHT agents exhibit specific absorption rate (SAR) values of 197 and 205 W/g, correspondingly. Furthermore, the Q-MLs cytotoxicity was studied on the MCF-7 breast cancer cell line, and the obtained data demonstrated that the Q-MLs have a high cytotoxicity effect compared to MLs and free Q.

Hydrogel beads based on carboxymethyl cassava starch/alginate enriched with MgFe2O4 nanoparticles for controlling drug release

Implementing novel oral drug delivery systems with controlled drug release behavior is valuable in cancer therapy. Herein, a green synthetic approach based on the sol-gel technique was adopted to prepare MgFe₂O₄ nanoparticles at different calcination temperatures using citric acid as a chelating/combustion agent. In this context, pH-responsive and magnetic carboxymethyl starch/alginate hydrogel beads (CMCS-SA) containing the MgFe₂O₄ nanoparticles were developed as potential drug carriers for the anticancer drug (Doxorubicin, Dox) release in simulated gastrointestinal fluids. Furthermore, in vitro release behaviors validated that these beads illustrated excellent stability in the simulated stomach liquids. In contrast, the data in simulated intestinal fluids showed sustained release of Dox because of their pH-sensitive swelling characteristics. Notably, applying an external magnetic field (EMF) could accelerate drug release from the beads. The in vitro release of drugs from gel beads was mainly accomplished by a combination of diffusion, swelling and erosion. Moreover, the cell cytotoxicity test and laser confocal results showed no harmful effects on normal cells (3T3) but were significant cytotoxic to colon cancer cell lines (HCT116) by drug-loaded hydrogel beads. Therefore, the prepared gel beads could be qualified as latent platforms for controlling the release of anticancer drugs in cancer treatment.

Fabricating Dual-Functional Plasmonic-Magnetic Au@MgFe2O4 Nanohybrids for Photothermal Therapy and Magnetic Resonance Imaging

Bifunctional nanohybrids possessing both plasmonic and magnetic functionalities are of great interest for biomedical applications owing to their capability for simultaneous therapy and diagnostics. Herein, we fabricate a core-shell structured plasmonic-magnetic nanocomposite system that can serve as a dual-functional agent due to its combined photothermal therapeutic and magnetic resonance imaging (MRI) functions. The photothermal activity of the hybrid is attributed to its plasmonic Au core, which is capable of absorbing near-infrared (NIR) light and converting it into heat. Meanwhile, the magnetic MgFe₂O₄ shell exerts its ability to act as a MRI contrast agent. Our in vivo studies using tumor-bearing mice demonstrated the nanohybrids' excellent photothermal and MRI properties. As a photothermal therapeutic agent, the nanohybrids were able to dramatically shrink solid tumors in mice through NIR-induced hyperthermia. As T ₂-weighted MRI contrast agents, the nanohybrids were found capable of substantially reducing the MRI signal intensity of the tumor region at 10 min postinjection. With their dual plasmonic-magnetic functionality, these Au@MgFe₂O₄ nanohybrids hold great promise not only in the biomedical field but also in the areas of catalysis and optical sensing.

Development of photo-crosslinkable collagen hydrogel building blocks for vascular tissue engineering applications: A superior alternative to methacrylated gelatin?

The present work targets the development of collagen-based hydrogel precursors, functionalized with photo-crosslinkable methacrylamide moieties (COL-MA), for vascular tissue engineering (vTE) applications. The developed materials were physico-chemically characterized in terms of crosslinking kinetics, degree of modification/conversion, swelling behavior, mechanical properties and in vitro cytocompatibility. The collagen derivatives were benchmarked to methacrylamide-modified gelatin (GEL-MA), due to its proven track record in the field of tissue engineering. To the best of our knowledge, this is the first paper in its kind comparing these two methacrylated biopolymers for vTE applications. For both gelatin and collagen, two derivatives with varying degrees of substitutions (DS) were developed by altering the added amount of methacrylic anhydride (MeAnH). This led to photo-crosslinkable derivatives with a DS of 74 and 96% for collagen, and a DS of 73 and 99% for gelatin. The developed derivatives showed high gel fractions (i.e. 74% and 84%, for the gelatin derivatives; 87 and 83%, for the collagen derivatives) and an excellent crosslinking efficiency. Furthermore, the results indicated that the functionalization of collagen led to hydrogels with tunable mechanical properties (i.e. storage moduli of [4.8-9.4 kPa] for the developed COL-MAs versus [3.9-8.4 kPa] for the developed GEL-MAs) along with superior cell-biomaterial interactions when compared to GEL-MA. Moreover, the developed photo-crosslinkable collagens showed superior mechanical properties compared to extracted native collagen. Therefore, the developed photo-crosslinkable collagens demonstrate great potential as biomaterials for vTE applications.

A hybrid nanosensor based on novel fluorescent iron oxide nanoparticles for highly selective determination of Hg2+ ions in environmental samples

Novel fluorescent iron oxide nanoparticles were prepared for the determination of Hg²⁺ in real samples. The fluorescence behaviors of the sensor were examined using absorption and fluorescence (steady-state, time-resolved, 3-D, EEM) spectroscopies.

Tuning of spinel magnesium ferrite nanoparticles with enhanced magnetic properties

Monodispersed magnesium ferrite nanoparticles with enhanced magnetic properties were successfully fabricated by a simple solvothermal method without employing any templates, complex apparatus or techniques. The structure, morphology, composition, and magnetic properties of the products were tuned and characterized by X-ray powder diffraction, transmission electron microscopy, scanning electron microscopy and vibrating sample magnetometry. The results show that the reaction time and temperature have an important influence on the morphology, composition, structure and particle size of the synthesized MgFe₂O₄ nanoparticles. Not only the size, size distribution, crystallization, but also the atomic ratio of Mg : Fe has a decisive effect on their magnetic properties. The MgFe₂O₄ magnetic nanoparticles synthesized at 180 °C for 12 hours have excellent dispersion, narrow size distribution, good crystallinity and a Mg : Fe atomic ratio of approximately 1 : 4.53 and an average particle size of 114.3 nm, thus the highest saturation magnetization of 67.35 emu g⁻¹. It provides a reliable synthesis method for the better application of spinel structure magnesium ferrite nanoparticles in the future.

Monodispersed magnesium ferrite nanoparticles with enhanced magnetic properties were successfully fabricated by a simple solvothermal method without employing any templates, complex apparatus or techniques.

Fabrication and Characterization of Magnesium Ferrite-Based PCL/Aloe Vera Nanofibers

Composite nanofibers of biopolymers and inorganic materials have been widely explored as tissue engineering scaffolds because of their superior structural, mechanical and biological properties. In this study, magnesium ferrite (Mg-ferrite) based composite nanofibers were synthesized using an electrospinning technique. Mg-ferrite nanoparticles were first synthesized using the reverse micelle method, and then blended in a mixture of polycaprolactone (PCL), a synthetic polymer, and Aloe vera, a natural polymer, to create magnetic nanofibers by electrospinning. The morphology, structural and magnetic properties, and cellular compatibility of the magnetic nanofibers were analyzed. Mg-ferrite/PCL/Aloe vera nanofibers showed good uniformity in fiber morphology, retained their structural integrity, and displayed magnetic strength. Experimental results, using cell viability assay and scanning electron microscopy imaging showed that magnetic nanofibers supported 3T3 cell viability. We believe that the new composite nanofibrous membranes developed in this study have the ability to mimic the physical structure and function of tissue extracellular matrix, as well as provide the magnetic and soluble metal ion attributes in the scaffolds with enhanced cell attachment, and thus improve tissue regeneration.

Luteinizing hormone-releasing hormone targeted superparamagnetic gold nanoshells for a combination therapy of hyperthermia and controlled drug delivery

In this, we developed superparamagnetic iron oxide nanoparticles (SPIONs) to be appropriate for the diagnosis and treatment of cancer cells by means of magnetic resonance imaging (MRI) and magnetically controlled hyperthermia/drug delivery (respectively). For the preparation of composite, we started with SPIONs, followed by its coating with gold to form SPIONs@Au, which further conjugated with luteinizing hormone-releasing hormone (LHRH) protein by making use of the cysteamine (Cyst) space linker and finally loaded with 5-Fluororacil (5-Fu) anticancer drug to form SPIONs@Au-Cyst-LHRH_5-Fu composite. Thus formed composite was thoroughly characterized by making use of the instrumental analysis such as HRTEM, EDAX, DLS, TGA, XPS, UV-vis, FTIR, HPLC and SQUID magnetics. We found from the analysis that the particles are spherical in shape, monodispersed with a size distribution of around 6.9nm in powdered dry form, while in solution phase it is 8.7nm. The UV-vis, FTIR, and HPLC studies confirmed for the loading of the 5-Fu drug onto the surface of SPIONs core and the maximum amount of drug that got adsorbed to be about 42%. The SQUID magnetic studies provided the information for the superparamagnetic behavior of the drug loaded SPIONs and the saturation magnetization (Ms) values observed to be about 11emu/g and the blocking temperature (T_B) of 348K. On testing the particles to see the effects of magnetic fluid hyperthermia (MFH) due to some changes in the solvent medium and oscillating frequency, the material seems to be highly active in aqueous medium and the activity gets increased with respect to the applied frequency of oscillation (430Hz>230Hz>44Hz). From the heat release studies, the calculated specific power loss (SPL) values for the SPIONs@Au-Cyst-LHRH_5-Fu composite are at the highest of 1068W/g in water (430Hz) vs the least of 68W/g in toluene (44Hz). Further, the drug release studies tested under the influence of magnetic field provided the information that the composite released its entire loaded drug following an exposure to the magnetic field (430Hz over 4h time), while only 53% (over 5h) for the controlled measurements of no magnetic field, thereby supporting to have the magnetic field so as to observe the externally controlled drug release effects. Finally, the results of the study provide the information that the SPIONs@Au-Cyst-LHRH_5-Fu composite can be potential for theranostic applications of cancer through the phenomenon of applying for MRI, magnetically controlled hyperthermia and drug delivery externally.