Green nanotechnology offers a sustainable and eco-friendly pathway for large-scale nanoparticle synthesis, minimizing environmental hazards associated with conventional chemical methods. In this study, we report the phyco-synthesis of iron oxide nanoparticles (FeONPs) using Arthrospira sp., a cyanobacterium enriched with diverse bioactive compounds, as both a reducing and stabilizing agent. Despite extensive exploration of algal mediated nanoparticle synthesis, the biomedical potential of Arthrospira derived FeONPs remains largely underexplored. Here, FeONPs were synthesized via a two-step process involving the reaction of Arthrospira sp. aqueous extract with ferric chloride under optimized conditions, followed by calcination. The resultant FeONPs were comprehensively characterized through ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), dynamic surface analysis (DSA), and zeta potential measurements. Biomedical evaluation was performed through multiple in vitro assays, including assessments of antioxidant, antimicrobial, anti-inflammatory, anti-diabetic, and cytotoxic activities. The FeONPs exhibited pronounced antioxidant potential (IC50: 81.91–453.04 µg/mL), and notable antifungal activity against Aspergillus flavus (IC50: 22.51 µg/mL). Furthermore, they demonstrated dose-dependent α-amylase inhibition (IC50: 591 µg/mL), low cytotoxicity (IC50: 1324 µg/mL), and excellent biocompatibility. This study pioneers Arthrospira sp. as a scalable, cost-effective biofactory for the sustainable production of FeONPs, bridging the gap between green synthesis and biomedical applications. Future investigations will focus on in vivo validation, elucidation of antimicrobial mechanisms, and integration into drug delivery systems. With their multifunctional bioactivities, Arthrospira sp. mediated FeONPs hold significant promise for next-generation nanotherapeutics, leading towards a new paradigm in sustainable nanomedicine.

Enzymes， as biological catalysts， have garnered significant interest due to their exceptional efficiency and specificity. However， the fragility of natural enzymes under varying temperature and pH conditions significantly restricts their broader utilization. In the past few years， noteworthy advancements have been achieved in creating biomimetic enzyme systems. Scientists have effectively designed artificial enzyme-mimicking systems that exhibit outstanding performance through the integration of various components， including small molecule compounds， deoxyribonucleic acid， and nanomaterials. These systems not only exhibit remarkable catalytic efficiency but also offer considerable benefits， such as adjustable activity， simplicity in modification， and enhanced stability and reusability. Nanomachines， as a new type of enzyme analogues， specifically refer to nanomaterials with enzyme-like catalytic functions. They have played a significant role in the development of biomimetic enzyme systems. Since the first report in 2007 that iron oxide nanoparticles have peroxidase （POD） mimicking activity， hundreds of nanomaterials have been confirmed to have catalytic activities similar to those of natural enzymes such as POD and oxidase （OXD）. These novel enzyme analogues not only exhibit a wide range of enzyme-like activities and structural similarity to natural enzymes， but also possess unique nanomaterial characteristics， making their catalytic activities controllable and stable. As effective substitutes for natural enzymes， nanomachines have been widely applied in fields such as biosensing， medical treatment， and environmental remediation. While every cutting-edge technology presents certain limitations， nanozymes are not an exception. They encounter notable challenges， especially concerning substrate selectivity， which is essential for effective targeted catalysis and widespread applicability. To address the aforementioned imitation， researchers have been investigating effective approaches to improve the catalytic selectivity of nanozymes. Primarily， two methods are utilized to achieve selective bioanalysis based on nanozyme catalysis： the first method involves merging nanozymes with biological recognition factors （such as natural enzymes， antibodies， DNA strands， and aptamers）， while the second focuses on developing nanozymes that possess intrinsic catalytic specificity through techniques like structure-mimetic design， surface modifications， or molecular imprinting. Incorporating external biological recognition elements can undermine both the stability and cost-effectiveness of nanozymes. Additionally， the methods available for the effective conjugation of nanozymes with biological components are still in their infancy. The creation of structure-mimetic nanozymes tends to be intricate and requires meticulous regulation. In contrast， a straightforward and accessible method for generating substrate recognition sites on nanozymes is the application of molecular imprinting technology （MIT）. MIT replicates interactions between enzyme substrates or antibody-antigen pairs to fabricate a cavity that is precisely shaped and sized for a particular template molecule， thus facilitating accurate molecular recognition. Due to its exceptional specificity， stability， and reproducibility， MIT is widely utilized in various fields such as biosensing， medical diagnostics， pharmaceutical assessment， sample preparation， and fluorescent detection. Moreover， the inherent advantages of molecularly imprinted polymers （MIPs）， such as their economical nature， exceptional selectivity， remarkable thermochemical resilience， and the removal of the need for biologically derived techniques， have rendered molecular imprinting a feasible strategy for mimicking the roles of natural enzymes. Natural enzymes exhibit substrate specificity primarily due to the three-dimensional structure of their active sites. These active sites are meticulously shaped to ensure a perfect match with the spatial configuration of the intended substrate. Following this concept， molecular imprinting nanoenzymes cleverly integrate molecular imprinting techniques with the properties of nanoenzymes， allowing biomimetic catalysts to retain catalytic selectivity while also demonstrating remarkable substrate specificity. This paper first summarizes the fundamental characteristics of nanozymes， then elaborates on the conventional preparation processes for molecularly imprinted nanozymes， and thoroughly explores the impact of molecular imprinting on the catalytic performance of nanozymes. Through an analysis of typical cases， the latest research advancements in molecularly imprinted nanozymes biosensing field are introduced. Finally， this paper discusses the challenges encountered and future development directions in this area， aiming to provide theoretical references and practical guidance for the application of molecular imprinting and nanozymes in biosensing.

The persistence of cancer stem cells (CSCs) within deep tumors is a primary driver of therapeutic failure and relapse. Most large nanoparticles fail to penetrate deep tumors, and extra-small nanoparticles suffer from poor retention in tumors. To solve the "penetration-retention paradox", herein, we developed special extra-small iron oxide nanoparticles (IO) featuring an "AND logic-gate"-driven self-assembly to achieve both deep penetration and long retention in large tumors for efficient CSCs dismission. Typically, the poly(ethylene glycol) (PEG) shield of IO is functionalized with a tyrosine (T) and thioketal (TK) linker followed by β-lapachone (LAP) loading, forming TIO-TK-PEG@LAP. (i) The extra-small TIO-TK-PEG@LAP can penetrate into deep tumors, whose H2O2 cleaves the TK linker, detaching the PEG shield and exposing T residues. (ii) The H+ facilitates the release of Fe2+ from IO to react with H2O2, generating hydroxyl radicals (•OH). (iii) The •OH catalyzes covalent cross-linking of T residues, driving in situ self-assembly into IO aggregates (∼100 nm), prolonging tumor retention. (iv) After cellular uptake, the IO aggregates are degraded in the endosomes, releasing LAP and Fe2+. (v) LAP can be catalyzed to generate substantial H2O2, which synergizes with Fe2+ to amplify the Fenton reaction, generating explosive •OH to trigger ferroptosis of tumor cells.

Magnetoelectric materials, which generate electric fields in response to alternating magnetic stimulation, are increasingly recognized for their applications in neuromodulation, tissue engineering, wireless drug delivery, and cancer treatment. This study addresses the cytotoxicity concerns associated with heavy metals in traditional magnetoelectric composites by introducing a heat-mediated magnetoelectric approach utilizing biocompatible iron oxide nanoparticles and pyroelectric polymers, thereby enhancing biomedical safety. The nanoparticles were synthesized with controlled size and shape via thermal decomposition of iron oleate, employing an in situ temperature labeling technique that simplifies the synthesis process and ensures uniform particle formation. These nanoparticles, optimized for high heating efficiency, were combined with the pyroelectric polymer P(VDF-TrFE) to create composite films that exhibit a heat-mediated magnetoelectric effect. This effect involves an alternating magnetic field heating the nanoparticles, leading to reversible material depolarization and the generation of a pyroelectric current. We explored the magnetopyroelectric effect on cell differentiation, demonstrating excellent biocompatibility with neural progenitor cells and significant enhancement in neuronal differentiation, attributed to the synergistic effects of heat and electricity. The pro-differentiation mechanism of magnetopyroelectric stimulation involves phosphatidylinositol 3 kinase AKT pathway and calcium signaling. This heat-mediated magnetoelectric approach not only presents a potential for applications such as neuronal repair and targeted drug delivery but also provides a safer and more versatile alternative to conventional magnetoelectric materials.

Development and characterization of dual-functional polymeric hydrogels: A Sustainable approach for drug delivery and antimicrobial applications.

Clinical translation and landscape of superparamagnetic iron oxide nanoparticles.

Development of anti-EGFR targeted magnetic nanoparticles for doxorubicin delivery into triple negative breast cancer cells.

Assembly of filament-like supraparticles in confined vortex rings.

Heparin (HP) and dextran sulfate (DS) are well-known for their anti-thrombotic and immunomodulatory properties; however, a direct comparison of their immunological responses when used in drug delivery applications is lacking. This study addresses this gap by evaluating the immunological behavior of superparamagnetic iron oxide nanoparticles (SPIONs) coated with HP or DS in human whole blood, primary immune cells, endothelial cells, and in vivo. Both HP-SPIONs and DS-SPIONs effectively suppressed complement activation, as shown by reduced C3bc, C3bBbP, and TCC levels. Notably, HP-SPIONs activated monocytes (CD11b) and endothelial cells (ICAM-1, CD62P/E), whereas DS-SPIONs suppressed endothelial activation. DS-SPIONs were preferentially internalized by myeloid cells (∼50% neutrophils, ∼42% macrophages, ∼55% dendritic cells), while HP-SPIONs showed significantly lower uptake (<25% dendritic cells, ∼5% neutrophils). DS-SPIONs induced an immunosuppressive, pro-healing phenotype in murine and human macrophages, whereas HP-SPIONs drove a pro-inflammatory, M1-like response. In healthy mice, intravenous DS-SPIONs elicited a modest increase in splenic immune cell populations compared to HP-SPIONs, indicating early immune engagement. Collectively, both SPIONs attenuate complement activation, indicating high biocompatibility. Based on the early immunological responses, DS-SPIONs display a pro-healing immune profile suitable for regenerative drug delivery, whereas HP-SPIONs induce pro-inflammatory responses that may be leveraged for anticancer immunotherapy.

The hepatic accumulation of nanoparticles significantly impedes their diagnostic and therapeutic efficacy in biomedical applications. However, the precise role of specific physicochemical properties in determining nanoliver interaction remains poorly understood. This study utilizes 99mTc-labeled iron oxide nanoparticles to elucidate the effect of size (3.6 and 12.0 nm) and PEG chain length (1K, 2K, and 5K) on their hepatic interactions. In vivo SPECT/CT imaging reveals that small particles initially clear through the kidneys, while large particles predominantly accumulate in the liver and spleen, ultimately showing significant liver uptake. Longer PEG chains generally extend circulation time and slow hepatic uptake, with particles coated with 2K PEG exhibiting the lowest hepatic accumulation, suggesting an optimal balance between circulation time and hepatic sequestration. Complementary in vitro studies with primary liver cells─namely hepatocytes (HCs), liver sinusoidal endothelial cells (LSECs), Kupffer cells (KCs), and hepatic stellate cells (HSCs)─reveal complex uptake behaviors significantly influenced by particle size and PEG chain length. Contrary to conventional wisdom, the study identifies an uptake trend of HCs ∼ HSCs > LSECs > KCs, challenging the prevailing notion of KCs as the primary mediators of nanoparticle clearance. Bridging in vitro and in vivo observations, the hepatic accumulation of small particles closely correlates with uptake patterns in primary HCs, while the accumulation of large particles is linked to interactions with LSECs and KCs. These results highlight the importance of cellular microenvironments in nanoliver interactions, offering design guidance for optimizing nanomedicines to achieve enhanced specificity and reduced off-target effects.

Plant-mediated synthesis of biocompatible Fe3O4 nanoparticles for magnetic hyperthermia therapy: A preclinical study in pharmaceutical nanotechnology.

Nanocomposite materials have garnered significant attention in advanced materials science due to their unique ability to exhibit multifunctional properties, particularly in the realm of magnetism and electromagnetic responsiveness. This study focuses on the development and characterization of acrylonitrile butadiene styrene (ABS) polymer matrix reinforced with ferromagnetic iron oxide (Fe3O4) nanoparticles. The primary objective was to investigate the electromagnetic properties of the nanocomposite and evaluate its potential for use in smart materials, sensors, and actuators via 4D printing. The nanocomposite was fabricated using a melt-mixing process, wherein Fe3O4 nanoparticles were incorporated into the ABS thermoplastic matrix at varying concentrations ranging from 10 to 20 wt. %. The mixture was then extruded into long, continuous 3D printing filaments and then to rectangular plates to facilitate testing and analysis. Its response to electromagnetic radiation was characterized by magnetic pull test using a 12 V DC Arduino-controller. An analytical model was developed and is validated using experiments. Experimental tests showed that the material exhibited significant magnetic receptiveness, by pulling and displacing the samples when subjected to applied magnetic field. The results indicated that increasing the concentration of Fe3O4 nanoparticles enhanced the material’s sensitivity, highlighting its potential for applications requiring precise control over magnetic interactions. Further, external magnetic field strength and sample dimensions are also shown to be significant parameters. In conclusion, this research underscores the potential of Fe3O4-reinforced polymer nanocomposites as a versatile and innovative material system for electromagnetic sensitivity.

Hexamine-functionalized iron oxide nanoparticles: An eco-friendly magnetically recoverable organobase catalyst for water-mediated synthesis 2-aryl-2,3-dihydroquinazolin-4(1H)-ones

Small molecule-stabilized exceedingly small magnetic iron oxide nanoparticles as a contrast agent of T1-weighted magnetic resonance imaging.

Biological properties of Iron Oxide Nanoparticles and Bone Morphogenetic Protein 2 functionalized biomaterials for bone tissue engineering, from a molecular perspective: A Review

Multimodal Iron Oxide Nanoparticles for Breast Cancer Theranostics and Clinical Translation: From Bench to Bedside

Mechanistic insights into iron oxide nanoparticles-induced iron deregulation and mitochondrial dysfunction in yellow catfish Pelteobagrus fulvidraco: Comparison with ferrous sulphate.

In this study, iron(III) oxide (Fe2O3) nanoparticles were synthesized using two approaches namely a conventional chemical co-precipitation method and a green synthesis route utilizing Azadirachta indica leaf extract, which simultaneously functions as a reducing and stabilizing agent. Following synthesis, the nanoparticles underwent characterization to assess their optical behaviour along with structural and morphological features. Through XRD characterization, Fe2O3 was identified in its rhombohedral crystalline configuration, with average particle sizes measured as 42 nm for co-precipitation-derived samples and 35 nm for those synthesized via the green route. Scanning electron microscopy (SEM) revealed size variations between the two synthesis routes, with the green method producing relatively smaller and more uniformly dispersed nanoparticles. UV-Vis absorption spectra indicated the characteristic optical transitions with slight band gap variations, attributed to particle size and surface modifications by phytochemicals present in the neem extract. Fourier-transform infrared spectroscopy revealed characteristic Fe–O bond vibrations together with biomolecular groups in Fe2O3 nanoparticles produced via the neem-assisted route. Antimicrobial testing performed using the agar well diffusion method against Staphylococcus aureus and Escherichia coli showed that the green-synthesized particles achieved greater inhibition zones. This enhancement is associated with their nanoscale size, enlarged surface-to-volume ratio and the functional bioactive molecules originating from neem extract. Overall, the study underscores the potential of green synthesis for designing effective and biocompatible antibacterial nanomaterials.

Accurate prediction of the specific absorption rate (SAR) of superparamagnetic iron oxide nanoparticles (SPIONs) is critical for optimizing their performance in magnetic hyperthermia applications. This study presents the development of a predictive model for SAR using advanced machine learning techniques and a systematically curated dataset comprising1850 entries from84 published studies, capturing30 predictive featuresrelated to SPION properties and experimental parameters. Twelve machine learning algorithms were evaluated and optimized using Bayesian hyperparameter tuning. The CatBoost algorithm emerged as the top-performing model(R2=0.98) with the lowest prediction errors.Shapley additive explanation analysis revealed alternating magnetic field amplitude and frequency as the most influential factors determining SAR, followed by SPION concentration and core surface area. Model reliability was confirmed through conformal prediction, providing a prediction interval of±62W g-1. Validation using an independent dataset of SPIONs with varying sizes (7-30nm) and dopants (Zn, Mn, Mg, Co) demonstrated strong predictive performance for small nanoparticles (≈7nm), with increased variability for larger particles. These findings demonstrate that advanced machine learning models enable accurate SAR prediction and provide critical insights into nanoparticle design, supporting thesystematic optimizationof SPIONs for clinical magnetic hyperthermia applications.

ABSTRACT This research has prepared an eco-friendly alternative magnetic adsorbent, which removed lead (Pb+2) and cadmium (Cd+2) ions from aqueous solutions via the co-precipitation. The banana peels were impregnated with magnetic iron oxide (Fe3O4) nanoparticles before using them as an adsorbent to increase their efficiency for adsorption as well as for magnetic separation. A comparison between Fourier Transforms Infrared Spectroscopy (FTIR) analysis revealed a diminished peak corresponding to carbonyl (C=O) at 1740 cm−1 and a new peak appearing at 570 cm−1 which confirms the presence of the Fe-O bond thus supporting the successful immobilisation of the nanoparticle. The X-ray diffraction pattern showed the crystalline phase of Fe3O4, while scanning electron microscopy illustrated the fairly distributed nanoparticles on the peel surface. Both pH variations and initial concentration of ions along with contact time were considered. The optimum conditions were found when the pH was 5.0, a contact time of 90 minutes was enriched with 0.1 grams of adsorbent, using 50 mL of solution having an initial concentration of 50 mg/L, and showed maximum removal efficiencies of 98.6% Pb+2 and 94.3% Cd+2. Kinetic modelling data suggested that the process followed pseudo-second-order kinetics (R2 > 0.995). The composite showed a greater advantage over the raw banana peel and Fe3O4 alone with regard to magnetic separation ability and reuse, up to five cycles with above 85% efficiency, with negative ΔG° values (−5.82 to −7.75 kJ/mol) and positive ΔH° (106.45 kJ/mol) and ΔS° (25.91 J/mol·K), so the adsorption process was spontaneous and endothermic.