Synthesis and characterization of magnetic nanoparticles coated with polystyrene sulfonic acid for biomedical applications

Synthesis and Characterization of Maghemite Nanoparticles Functionalized with Poly(Sodium 4-Styrene Sulfonate) Saloplastic and Its Acute Ecotoxicological Impact on the Cladoceran Daphnia magna

Using a modified co-precipitation method, 11(2) nm γ-Fe2O3 nanoparticles functionalized with PSSNa [Poly(sodium 4-styrenesulfonate)] saloplastic polymer were successfully synthesized, and their structural, vibrational, electronic, thermal, colloidal, hyperfine, and magnetic properties were systematically studied using various analytic techniques. The results showed that the functionalized γ-Fe2O3/PSSNa nanohybrid has physicochemical properties that allow it to be applied in the magnetic remediation process of water. Before being applied as a nanoadsorbent in real water treatment, a short-term acute assay was developed and standardized using a Daphnia magna biomarker. The ecotoxicological tests indicated that the different concentrations of the functionalized nanohybrid may affect the mortality of the Daphnia magna population during the first 24 h of exposure. A lethal concentration of 533(5) mg L-1 was found. At high concentrations, morphological changes were also seen in the body, heart, and antenna. Therefore, these results suggested the presence of alterations in normal growth and swimming skills. The main changes observed in the D. magna features were basically caused by the PSSNa polymer due to its highly stable colloidal properties (zeta potential > -30 mV) that permit a direct and constant interaction with the Daphnia magna neonates.

Electrospun zein nanofibers loaded with curcumin as a wound dressing: enhancing properties with PSS and PDADMAC layers

Development of wound dressings with enhanced therapeutic properties is of great interest in the modern healthcare. In this study, a zein-based nanofibrous wound dressing containing curcumin as a therapeutic agent was fabricated through electrospinning technique. In order to achieve desirable properties, such as antibacterial characteristics, reduced contact angle, and enhanced mechanical properties, the layer-by-layer technique was used for coating the surfaces of drug-loaded nanofibers by sequentially incorporating poly (sodium 4-styrene sulfonate) as a polyanion and poly (diallyldimethylammonium chloride) (PDADMAC) as a polycation. Various analyses, including scanning electron microscopy, Fourier transform infrared spectroscopy, drug release assessment., and mechanical tests were employed to assess the characteristics of the prepared wound dressings. Based on the results, coating with polyelectrolytes enhanced the Young's modulus and tensile strength of the electrospun mat from 1.34 MPa and 4.21 MPa to 1.88 MPa and 8.83 MPa, respectively. The coating also improved the controlled release of curcumin and antioxidant activity, while the outer layer, PDADMAC, exhibited antibacterial properties. The cell viability tests proved the appropriate biocompatibility of the prepared wound dressings. Moreover, our findings show that incorporation of the coating layers enhances cell migration and provides a favorable surface for cell attachment. According to the findings of this study, the fabricated nanofibrous wound dressing can be considered a promising and effective therapeutic intervention for wound management, facilitating the healing process.

Biomedical applications of biodegradable polycaprolactone-functionalized magnetic iron oxides nanoparticles and their polymer nanocomposites

Magnetic nanoparticles (MNPs) have gained significant attention among several nanoscale materials during the last decade due to their unique properties. These properties make them successful nanofillers for drug delivery and a number of new biomedical applications. MNPs are more useful when combined with biodegradable polymers. In this review, we discussed the synthesis of polycaprolactones (PCL) and the various methods of synthesizing magnetic iron oxide nanoparticles. Then, the synthesis of composites that is made of PCL and magnetic materials (with special focus on iron oxide nanoparticles) were highlighted. In addition, we comprehensively reviewed their application in drug delivery, cancer treatment, wound healing, hyperthermia, and bone tissue engineering. Other biomedical applications of the magnetic PCL such as mitochondria targeting are highlighted. Moreover, biomedical applications of magnetic nanoparticles incorporated into other synthetic polymers apart from PCL are also discussed. Thus, great progress and better outcome with functionalized MNPs enhanced with polycaprolactone has been recorded with the biomedical applications of drug delivery and recovery of bone tissues.

Immune-regulating camouflaged nanoplatforms: A promising strategy to improve cancer nano-immunotherapy

Although nano-immunotherapy has advanced dramatically in recent times, there remain two significant hurdles related to immune systems in cancer treatment, such as (namely) inevitable immune elimination of nanoplatforms and severely immunosuppressive microenvironment with low immunogenicity, hampering the performance of nanomedicines. To address these issues, several immune-regulating camouflaged nanocomposites have emerged as prevailing strategies due to their unique characteristics and specific functionalities. In this review, we emphasize the composition, performances, and mechanisms of various immune-regulating camouflaged nanoplatforms, including polymer-coated, cell membrane-camouflaged, and exosome-based nanoplatforms to evade the immune clearance of nanoplatforms or upregulate the immune function against the tumor. Further, we discuss the applications of these immune-regulating camouflaged nanoplatforms in directly boosting cancer immunotherapy and some immunogenic cell death-inducing immunotherapeutic modalities, such as chemotherapy, photothermal therapy, and reactive oxygen species-mediated immunotherapies, highlighting the current progress and recent advancements. Finally, we conclude the article with interesting perspectives, suggesting future tendencies of these innovative camouflaged constructs towards their translation pipeline.

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Various immune-regulating camouflaged nanoplatforms are emphasized.

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Immunotherapeutic applications of camouflaged nanoplatforms are systematically summarized.

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ICD-induced therapeutic modalities based on these nanoplatforms are discussed.

Bioinspired Synthesis of Magnetic Nanoparticles Based on Iron Oxides Using Orange Waste and Their Application as Photo-Activated Antibacterial Agents

Magnetic nanoparticles based on iron oxides (MNPs-Fe) have been proposed as photothermal agents (PTAs) within antibacterial photothermal therapy (PTT), aiming to counteract the vast health problem of multidrug-resistant bacterial infections. We present a quick and easy green synthesis (GS) to prepare MNPs-Fe harnessing waste. Orange peel extract (organic compounds) was used as a reducing, capping, and stabilizing agent in the GS, which employed microwave (MW) irradiation to reduce the synthesis time. The produced weight, physical-chemical features and magnetic features of the MNPs-Fe were studied. Moreover, their cytotoxicity was assessed in animal cell line ATCC RAW 264.7, as well as their antibacterial activity against Staphylococcus aureus and Escherichia coli. We found that the 50GS-MNPs-Fe sample (prepared by GS, with 50% v/v of NH₄OH and 50% v/v of orange peel extract) had an excellent mass yield. Its particle size was ~50 nm with the presence of an organic coating (terpenes or aldehydes). We believe that this coating improved the cell viability in extended periods (8 days) of cell culture with concentrations lower than 250 µg·mL^-1, with respect to the MNPs-Fe obtained by CO and single MW, but it did not influence the antibacterial effect. The bacteria inhibition was attributed to the plasmonic of 50GS-MNPs-Fe (photothermal effect) by irradiation with red light (630 nm, 65.5 mW·cm^-2, 30 min). We highlight the superparamagnetism of the 50GS-MNPs-Fe over 60 K in a broader temperature range than the MNPs-Fe obtained by CO (160.09 K) and MW (211.1 K). Therefore, 50GS-MNPs-Fe could be excellent candidates as broad-spectrum PTAs in antibacterial PTT. Furthermore, they might be employed in magnetic hyperthermia, magnetic resonance imaging, oncological treatments, and so on.

Progress in the preparation of Prussian blue-based nanomaterials for biomedical applications

Prussian blue (PB) is composed of the coordination network of Fe²⁺-CN-Fe³⁺ mixed valence state as a classic metal complex, which includes a C atom and Fe²⁺ (low spin), N atom and Fe³⁺ (high spin). PB and its analogues (PBA) have excellent biosafety, good magnetic properties, outstanding photothermal properties and the ability to mimic enzymatic behaviors due to their stable structure, tunable size, controllable morphology, abundant modification methods and excellent physicochemical properties. They have received increasing research interest and have shown promising applications in the biomedical field. Here, progress in the preparation of PB-based nanomaterials for biomedical applications is summarized and discussed. The preparation strategies, traditional synthesis and emerging preparation methods of PB are summarized systematically in this review. The design and preparation of PBA, PB(PBA)-based hollow structures and PB(PBA)-based composites are also included. While introducing the preparation status, some PB-based nanomaterials that have performed well in specific biomedical fields are emphasized. More importantly, the key factors and future development of PB for the clinical translation as multifunctional nanomaterials are also discussed. This review provides a reference for the design and biomedical application of PB-based nanomaterials.

Preparation of Functionalized Magnetic Polystyrene Microspheres and Their Application in Food Safety Detection

Based on the specific binding of sulfonic acid groups to melamine, β-agonists and other compounds, Fe₃O₄ nano-magnetic beads were coated with polystyrene using an improved micro-suspension emulsion polymerization method, thus forming core-shell magnetic polystyrene microspheres (Fe₃O₄@PS) with Fe₃O₄ as the core and polystyrene as the shell. These functionalized microspheres, which can be used as magnetic solid-phase extraction (MSPE) adsorbent, were prepared after further sulfonation. These microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size analysis and saturation magnetization measurement. The results showed that these sulfonated magnetic polystyrene microspheres had favorable sphericity. The particle size of these microspheres ranged from 1 μm to 10 μm. Additionally, these microspheres had good dispersion and magnetic responses in both inorganic and organic solvents. Moreover, these functionalized magnetic polystyrene microspheres were tested and evaluated by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The results indicated that these sulfonated magnetic polystyrene microspheres (Fe₃O₄@SPS) could effectively adsorb such illegal additives as β-agonists and melamine in the food matrix.

Super-assembly of integrated gold magnetic assay with loop-mediated isothermal amplification for point-of-care testing

With the increasing global threat of various diseases and infections, it is essential to develop a fast, low-cost, and easy-to-use point-of-care testing (POCT) system for inspections at all levels of medical institutions and self-examination at home. In this work, gold magnetic nanoparticles (GMNPs) are used as the key material, and a rapid visual detection method is designed through integrating loop-mediated isothermal amplification (LAMP) and lateral flow assay (LFA) biosensor for detecting a variety of analytes which includes whole blood, buccal swabs, and DNA. It is worth to note that the proposed method does not need DNA extraction. Furthermore, uracil DNA glycosylase (UDG) is employed to eliminate carrier contamination for preventing false positive results. The whole detection process can be finished within 25 min. The accuracy of detection is measured by assessing the polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) C677T. The detection limit of the newly developed extraction-free detection system for MTHFR C677T is 0.16 ng/μL. A preliminary clinical study of the proposed method is carried out by analyzing 600 clinical samples (including 200 whole blood samples, 100 buccal swabs, and 300 genomic DNA samples). The results indicate that the proposed method is 100% consistent with the sequencing results which provides a new choice for POCT and shows a broad application prospect in all levels of medical clinics and at home.

ELECTRONIC SUPPLEMENTARY MATERIAL

Supplementary material (details for MTHFR C677T primer sequences, the cell count results of samples at different dilution ratios, genotyping results and frequency samples, a Hardy-Weinberg equilibrium test, the sensitivity of the system, detection results of multiple samples, and optimization of the system) is available in the online version of this article at 10.1007/s12274-022-4692-9.

Progress toward Room-Temperature Synthesis and Functionalization of Iron-Oxide Nanoparticles

Novel magnetic nanohybrids composed of nanomaghemite covered by organic molecules were successfully synthesized at room temperature with different functionalization agents (sodium polystyrene sulfonate, oxalic acid, and cetyltrimethylammonium bromide) in low and high concentrations. Structural, vibrational, morphological, electron energy-loss spectroscopy, magnetic, and Mössbauer characterizations unraveled the presence of mainly cubic inverse spinel maghemite (γ-Fe₂O₃), whilst X-ray diffraction and ⁵⁷Fe Mössbauer spectroscopy showed that most samples contain a minor amount of goethite phase (α-FeOOH). Raman analysis at different laser power revealed a threshold value of 0.83 mW for all samples, for which the γ-Fe₂O₃ to α-Fe₂O₃ phase transition was observed. Imaging microscopy revealed controlled-size morphologies of nanoparticles, with sizes in the range from 8 to 12 nm. Organic functionalization of the magnetic nanoparticles was demonstrated by vibrational and thermogravimetric measurements. For some samples, Raman, magnetic, and Mössbauer measurements suggested an even more complex core-shell-like configuration, with a thin shell containing magnetite (Fe₃O₄) covering the γ-Fe₂O₃ surface, thus causing an increase in the saturation magnetization of approximately 11% against nanomaghemite. Field cooling hysteresis curves at 5 K did not evidence an exchange bias effect, confirming that the goethite phase is not directly interacting magnetically with the functionalized maghemite nanoparticles. These magnetic nanohybrids may be suitable for applications in effluent remediation and biomedicine.

Simple Bottom-Up Synthesis of Bismuthene Nanostructures with a Suitable Morphology for Competitive Performance in the Electrocatalytic Nitrogen Reduction Reaction

Nitrogen reduction to ammonia under ambient conditions has received important attention, in which high-performing catalysts are sought. A new, facile, and seedless solvothermal method based on a high-temperature reduction route has been developed in this work for the production of bismuthene nanostructures with excellent performance in the electrocatalytic nitrogen reduction reaction (NRR). Different reaction conditions were tested, such as the type of solvent, surfactant, reducing agent, reaction temperature, and time, as well as bismuth precursor source, resulting in distinct particle morphologies. Two-dimensional sheet-like structures and small particles displayed very high electrocatalytic activity, attributed to the abundance of tips, edges, and high surface area. NRR experiments resulted in an ammonia yield of 571 ± 0.1 μg h^-1 cm^-2 with a respective Faradaic efficiency of 7.94 ± 0.2% vs Ag/AgCl. The easy implementation of the synthetic reaction to produce Bi nanostructures facilitates its potential scale up to larger production yields.

Recent development for biomedical applications of magnetic nanoparticles

In recent decades, the use of engineered nanoparticles has been increasing in various sectors, including biomedicine, diagnosis, water treatment, and environmental remediation leading to significant public concerns. Among these nanoparticles, magnetic nanoparticles (MNPs) have gained many attentions in medicine, pharmacology, drug delivery system, molecular imaging, and bio-sensing due to their various properties. In addition, various studies have reviewed MNPs main applications in the biomedical engineering area with intense progress and recent achievements. Nanoparticles, especially the magnetic nanoparticles, have recently been confirmed with excellent antiviral activity against different viruses, including SARS-CoV-2(Covid-19) and their recent development against Covid-19 also has also been discussed. This review aims to highlight the recent development of the magnetic nanoparticles and their biomedical applications such as diagnosis of diseases, molecular imaging, hyperthermia, bio-sensing, gene therapy, drug delivery and the diagnosis of Covid-19.

Development of Polymer-Assisted Nanoparticles and Nanogels for Cancer Therapy: An Update

With cancer remaining as one of the main causes of deaths worldwide, many studies are undergoing the effort to look for a novel and potent anticancer drug. Nanoparticles (NPs) are one of the rising fields in research for anticancer drug development. One of the key advantages of using NPs for cancer therapy is its high flexibility for modification, hence additional properties can be added to the NPs in order to improve its anticancer action. Polymer has attracted considerable attention to be used as a material to enhance the bioactivity of the NPs. Nanogels, which are NPs cross-linked with hydrophilic polymer network have also exhibited benefits in anticancer application. The characteristics of these nanomaterials include non-toxic, environment-friendly, and variable physiochemical properties. Some other unique properties of polymers are also attributed by diverse methods of polymer synthesis. This then contributes to the unique properties of the nanodrugs. This review article provides an in-depth update on the development of polymer-assisted NPs and nanogels for cancer therapy. Topics such as the synthesis, usage, and properties of the nanomaterials are discussed along with their mechanisms and functions in anticancer application. The advantages and limitations are also discussed in this article.

Poly(ethylene glycol)-Alendronate-Coated Magnetite Nanoparticles Do Not Alter Cardiovascular Functions and Red Blood Cells' Properties in Hypertensive Rats

In this study, magnetite nanoparticles were prepared and coated with poly(ethylene glycol) terminated by alendronate to ensure firm binding to the iron oxide surface. Magnetic nanoparticles, designated as magnetite coated with poly(ethylene glycol)-alendronate (Fe3O4@PEG-Ale), were characterized in terms of number-average (Dn) and hydrodynamic (Dh) size, ζ-potential, saturation magnetization, and composition. The effect of particles on blood pressure, vascular functions, nitric oxide (NO), and superoxide production in the tissues of spontaneously hypertensive rats, as well as the effect on red blood cell (RBC) parameters, was investigated after intravenous administration (1 mg Fe3O4/kg of body weight). Results showed that Fe3O4@PEG-Ale particles did negatively affect blood pressure, heart rate and RBC deformability, osmotic resistance and NO production. In addition, Fe3O4@PEG-Ale did not alter functions of the femoral arteries. Fe3O4@PEG-Ale induced increase in superoxide production in the kidney and spleen, but not in the left heart ventricle, aorta and liver. NO production was reduced only in the kidney. In conclusion, the results suggest that acute intravenous administration of Fe3O4@PEG-Ale did not produce negative effects on blood pressure regulation, vascular function, and RBCs in hypertensive rats.

Extracellular and intracellular intermittent magnetic-fluid hyperthermia treatment of SK-Hep1 hepatocellular carcinoma cells based on magnetic nanoparticles coated with polystyrene sulfonic acid

The use of magnetic nanoparticles (MNPs) magnetized on applying an alternating magnetic field (AMF) to stimulate the thermal characteristics and to induce tumor apoptosis is a currently active area of research in cancer treatment. In previous work, we developed biocompatible and superparamagnetic polystyrene-sulfonic-acid-coated magnetic nanoparticles (PSS-MNPs) as applications for magnetically labeled cell trapping, but without assessment of treatment effects on tumor diseases. In the present work, we examined PSS-MNP-induced magnetic fluid hyperthermia (MFH) on SK-Hep1 hepatocellular carcinoma (HCC) cells for lethal thermal effects with a self-made AMF system; an adjustable AMF frequency generated a variable intensity of magnetic field and induced MNP relaxation. The extracellular and intracellular MFH treatments on a SK-Hep1 cell line were implemented in vitro; the result indicates that the lethal effects were efficient and caused a significantly decreased cell viability of SK-Hep1 cells. As the PSS-MNP concentration decreased, especially in intracellular MFH treatments, the MFH effects on cells, however, largely decreased through heat spreading to the culture medium. On controlling and decreasing the volume of culture medium, the problem of heat spreading was solved. It can be consequently expected that PSS-MNPs would be a prospective agent for intracellular cancer magnetotherapy.