RETRACTION: Trace elements-based Auroshell gold@hematite nanostructure: Green synthesis and their hyperthermia therapy.

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.

Novel green synthesis approach of Fe3O4-MSN/Ag nanocomposite using moringa oleifera extract for magnetic hyperthermia applications

Superparamagnetic nanoparticles (SPMNPs) have attracted considerable attention in biomedicine, particularly magnetic hyperthermia for cancer treatment. However, the development of efficient and eco-friendly methods for synthesizing SPMNPs remains a challenge. This study reports on a green synthesis approach for SPMNPs using pomegranate peel extract as a stabilizing agent. The effects of various synthesis parameters, including the type of precipitating agent (NH3 and NaOH), N2 gas, extract volume, and pH, were systematically investigated with regard to the size, morphology, and magnetic properties of the nanoparticles. The results showed that reducing the volume of the extract increased the saturation magnetization of the nanoparticles. N2 gas was found to be essential in preventing the oxidation of the nanoparticles. The type of precipitating agent also affected the size and magnetization of the nanoparticles, with NaOH leading to the synthesis of SPMNPs with higher magnetization (∼4times) compared to NH3. Additionally, nanoparticles synthesized at pH 10 exhibited higher magnetization than those synthesized at pH 8 and 12. In conclusion, the optimized synthesis conditions significantly affected the magnetization and stability of SPMNPs. These nanoparticles are suitable for use in magnetic nanofluid hyperthermia applications.

Green synthesis and characterization of Mg0.93Na0.07O nanoparticles for antimicrobial activity, cytotoxicity and magnetic hyperthermia

Green synthesis, structure, cations distribution and bonding characteristics of superparamagnetic cobalt-zinc ferrites nanoparticles for Pb(II) adsorption and magnetic hyperthermia applications

Magnetic nanoparticles (MNPs) are multifunctional materials with superparamagnetic properties and tunable surface chemistries, making them valuable across diverse fields, such as biomedicine, environmental remediation, and agriculture. This review examines recent advancements in MNP synthesis, encompassing chemical, physical, and environmentally friendly methods while highlighting improvements in size, morphology, and composition control that enhance application‐specific performance and environmental sustainability. The review discusses various architectures, including single‐core, core–shell, hybrid composites, and stimuli–responsive systems, with an emphasis on their stability, scalability, and functionalization potential. In biomedical applications, MNPs show promise in targeted drug delivery, magnetic hyperthermia, and magnetic resonance imaging contrast enhancement, where biocompatibility, often achieved through green synthesis, is critical. In agriculture, iron oxide MNPs (Fe3O4) have been utilized as nanofertilizers and growth promoters, demonstrating the ability to improve seed germination, chlorophyll content, and root development in crops, such as maize and tomatoes, without exhibiting phytotoxicity. Despite these promising results, challenges remain in large‐scale production, reproducibility, and regulatory acceptance. This review highlights the pivotal role of MNPs in advancing nanotechnology‐driven solutions across the life sciences. Their evolving synthesis techniques, multifunctional properties, and cross‐sector applications position MNPs as key enablers of next‐generation technologies in diagnostics, therapeutics, environmental monitoring, and sustainable agriculture.

Spinel cobalt ferrite (CoFe2O4, CFO) nanoparticles (NPs) are a major focus of fundamental science and technological innovation due to their distinctive mix of magnetic, electrical, and chemical characteristics. CFO NPs have outstanding chemical stability, modest saturation magnetism (∼80 emu/g), a high Curie temperature (∼793 K), and significant magnetocrystalline anisotropy. These characteristics, further improved by cation substitution and surface functionalization, enable a wide range of applications. This review provides a comprehensive analysis of CFO NPs, covering their synthesis methods, physicochemical characterization, surface modifications, and diverse applications. We compare the environmental impact, scalability, yield, and particle size control of a variety of synthesis techniques, including co-precipitation, hydrothermal, sol-gel route, combustion method, microemulsion, thermal decomposition, electrochemical synthesis, polyol method, and green synthesis methods. The sustainable alternative of green synthesis, which employs plant- and microbe-mediated biosynthesis, is becoming increasingly important in the biomedical and environmental sectors. Furthermore, we explore advanced surface functionalization techniques that employ monomeric, inorganic, and polymeric stabilizers to improve the biocompatibility and stability of CFO NPs. The effects of cation substitution (such as transition metals and rare-earth dopants) on the physicochemical and magnetic properties of CFO NPs are examined in detail, addressing challenges like cost and stability in real-world applications. Moreover, the present review provides a detailed discussion correlating structural, morphological, magnetic, dielectric, optical, and electrical properties of CFO with synthesis methods and modifications. The traditional energy storage and conversion applications of CFO are comprehensively discussed. Additionally, the review highlights magnetic applications, biomedical applications (e.g., MRI contrast agents, magnetic hyperthermia, and biosensors), the role of CFO in electronics and optoelectronics, purification and catalysis applications, as well as advances in electromagnetic technologies. Emerging applications, including their roles in quantum computing, nanorobotics, tissue engineering, and bioimaging, are also discussed, emphasizing the cutting-edge potential of CFO NPs in multifunctional technologies. The objective of this review is to critically evaluate recent advancements, challenges, and future research directions to bridge the divide in understanding CFO NPs. This systematic evaluation establishes a strong foundation for researchers, allowing them to investigate novel applications of CFO NPs in both current and emerging technological domains.

Aim: The primary goal of this work was to synthesize low-cost superparamagnetic iron oxide nanoparticles (SPIONs) with the aid of coconut water and evaluate the ability of macrophages to internalize them. Our motivation was to determine potential therapeutic applications in drug-delivery systems associated with magnetic hyperthermia. Materials & methods: We used the following characterization techniques: x-ray and electron diffractions, electron microscopy, spectrometry and magnetometry. Results: The synthesized SPIONs, roughly 4nm in diameter, were internalized by macrophages, likely via endocytic/phagocytic pathways. They were randomly distributed throughout the cytoplasm and mainly located in membrane-bound compartments. Conclusion: Nanoparticles presented an elevated intrinsic loss power value and were not cytotoxic to mammalian cells. Thus, we suggest that low-cost SPIONs have great therapeutic potential.

Hyperthermia is an additional treatment method to radiation therapy/chemotherapy, which increases the survival rate of patients without side effects. Nowadays, Auroshell nanoparticles have attracted much attention due to their precise control over heat use for medical purposes. In this research, iron/gold Auroshell nanoparticles were synthesised using green nanotechnology approach. Auroshell gold@hematite nanoparticles were synthesised and characterised with rosemary extract in one step and the green synthesised nanoparticles were characterised by X‐ray powder diffraction, SEM, high‐resolution transmission electron microscopy, and X‐ray photoelectron spectroscopy analysis. Cytotoxicity of Auroshell iron@gold nanoparticles against normal HUVEC cells and glioblastoma cancer cells was evaluated by 2,5‐diphenyl‐2H‐tetrazolium bromide method, water bath hyperthermia, and combined method of water bath hyperthermia and nano‐therapy. Auroshell gold@hematite nanoparticles with minimal toxicity are safe against normal cells. The gold shell around the magnetic core of magnetite caused the environmental and cellular biocompatibility of these Auroshell nanoparticles. These magnetic nanoparticles with targeted control and transfer to the tumour tissue led to uniform heating of malignant tumours as the most efficient therapeutic agent.

Research and utilization of nanotechnology are growing exponentially in every aspect of life. The constant growth of applications for magnetic nanoparticles, specifically nanoferrites, attracted many researchers. Among them, nanocobalt ferrite is the most crucial and studied magnetic nanoparticle. Environmentally benign synthetic methods became necessary to minimize environmental and occupational hazards. Green synthesis approaches in science and technology are now widely applied in the synthesis of nanomaterials. Herein, we reviewed recent advances in synthesizing nanocobalt ferrites and their composites using various scientific search engines. Subsequently, various applications were discussed, such as environmental (treatment of water/wastewater, photocatalytic degradation of dyes, and nanosorbent for environmental remediation) and biomedical (nanobiosensors for cancer diagnosis at the primary stage, effective targeted drug delivery, magnetic resonance imaging, hyperthermia, and potential drug candidates against cancer and microbial infections). This review offers comprehensive knowledge on how to choose appropriate natural resources for the green synthesis of nanocobalt ferrite and the benefits of this approach compared to conventional methods.

The study of magnetic nanoparticles (MNPs) is an emergent field of science in this era due to their widespread utilization in the various fields of biomedical science. Developing concerns of magnetic nanoparticles in the researcher’s field led to design a huge number of MNPs including individual or binary metallic particles, oxides, (ferrites), biopolymer coated composites, metallic carbides and graphene mediated nanoparticles. Numerous synthetic routes are defined in literature to attain the desired size, crystal structure, morphology and magnetic properties. To build up biocompatibility, MNPs subjected to surface treatments by coating with some suitable organic or inorganic biomaterials which not only improves its physical characteristics but also elevate its chemical stability. These biomaterials coat either isolatly or in a combined state to enhance the colloidal stability, magnetic properties as well as prevent it cytotoxicity and surface corrosion in the biological media. These properties are essential for the particles and empowering their effectiveness in various biomedical science i.e., drug delivery Magnetic resonance imaging (MRI), hyperthermia, biosensors and gene therapy etc. Current review recapitulates the verdicts of previous research on the subject of magnetic nanoparticles. It will also explain the recent advancements of biomaterials that execute a dynamic role in various medical treatments. Our main focus is to report the particle types, design and properties as well as discussing various synthetic routes including sol gel, co-precipitation, microemulsion, green synthesis, sonochemical method and polyol synthesis etc. These methods produced particles of excellent yield with unique magnetic properties, coercivity and crystallinity and enhanced biocompatibility as compared to traditional methods used to develop MNPs.

The green synthesis of nanoparticles (NPs) has become a matter of great interest. There is a growing need to develop green and eco-friendly approaches which do not use toxic and hazardous chemical materials in the synthesis protocols. There are numerous scientific reports in the field of nanoparticle biosynthesis using organisms. Magnetic NPs have different applications in radionuclide therapy, drug delivery, magnetic resonance imaging (MRI), diagnostics, immunoassays, molecular biology, DNA and RNA purification, cell separation and purification, cell adhesion research, hyperthermia, and wastewater treatment. This chapter provides an overview of green bio-based synthesis of magnetic NPs as well as their applications in environmental, biomedical, and clinical fields.

Relevant properties of gold nanoparticles, such as stability and biocompatibility, together with their peculiar optical and electronic behavior, make them excellent candidates for medical and biological applications. This review describes the different approaches to the synthesis, surface modification, and characterization of gold nanoparticles (AuNPs) related to increasing their stability and available features useful for employment as drug delivery systems or in hyperthermia and photothermal therapy. The synthetic methods reported span from the well-known Turkevich synthesis, reduction with NaBH4 with or without citrate, seeding growth, ascorbic acid-based, green synthesis, and Brust–Schiffrin methods. Furthermore, the nanosized functionalization of the AuNP surface brought about the formation of self-assembled monolayers through the employment of polymer coatings as capping agents covalently bonded to the nanoparticles. The most common chemical–physical characterization techniques to determine the size, shape and surface coverage of AuNPs are described underlining the structure–activity correlation in the frame of their applications in the biomedical and biotechnology sectors.

The development of targeted cancer therapies is crucial to reducing harmful patient side effects. The incorporation of magnetic and fluorescent nanoparticles as heat mediators in magnetic hyperthermia is a novel and efficient strategy. This study investigated the potential of CoFe2O4/ZnS composite nanoparticles, successfully fabricated using a green synthesis method with Moringa oleifera leaf extract, as magnetic hyperthermia agents. X-ray diffraction spectra demonstrated the existence of the CoFe2O4 cubic spinel ferrite and ZnS cubic zinc-blend phases in the composite nanoparticles. The average particle sizes of CoFe2O4 and CoFe2O4/ZnS were 12 and 17 nm, respectively. The peak at 1406-1411 cm−1 indicated the incorporation of ZnS on the surfaces of the CoFe2O4/ZnS composite nanoparticles through the SO functional group. The UV–visible spectra showed that the bandgap increased from 3.7 to 4.5 eV with increasing ZnS content. Magnetic property studies indicated that the coercivity and saturation magnetization of the CoFe2O4/ZnS composite nanoparticles were lower than those of the CoFe2O4 nanoparticles but still showed ferromagnetic characteristics. Heating properties were investigated by measuring the specific absorption rate (SAR) in an alternating magnetic field at various ZnS contents. The SAR of the CoFe2O4 composite nanoparticles was 85.7 mW/g while that of the CoFe2O4/ZnS composite nanoparticles increased from 87.8 to 132.9 mW/g with increasing ZnS content. Results indicate that green-synthesized CoFe2O4/ZnS composite nanoparticles are promising candidates for magnetic hyperthermia applications in cancer therapy.

Gold‐coated silver nanoparticles (Ag@AuNPs) are synthesized by green synthesis using Vaccinium corymbosum as reducing agent. The obtained Ag@AuNPs present a core‐shell structure with nanostar shape. The absorption spectrum of these nanoparticles shows a prominent band centred at 680 nm, within the optimal range for photothermal applications. Dispersions of Ag@AuNPs in water, 1.87 1010 NPs/mL, reach a temperature of 44.3 °C under laser excitation in 10 minutes, which is suitable for hyperthermia therapy. The internalization of Ag@AuNPs, at a concentration of 3 108 NPs/ml, by macrophages (Raw 264.7), human fibroblasts (Hs27), and cancer cells (4T1) is confirmed by transmission electron microscopy. Cytotoxicity studies demonstrate that at this concentration the cells are viable.