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Definition: Magnetic nanoparticles (MNPs) have great potential in various areas such as medicine, cancer therapy and diagnostics, biosensing, and material science. In particular, magnetite (Fe3O4) nanoparticles are extensively used for numerous bioapplications due to their biocompatibility, high saturation magnetization, chemical stability, large surface area, and easy functionalization. This paper describes magnetic nanoparticle physical and biological properties, emphasizing synthesis approaches, toxicity, and various biomedical applications, focusing on the most recent advancements in the areas of therapy, diagnostics, theranostics, magnetic separation, and biosensing. [ABSTRACT FROM AUTHOR]

35631580 3 Iacovita C., Fizesan I., Nitica S., Florea A., Barbu-Tudoran L., Dudric R., Pop A., Vedeanu N., Crisan O., Tetean R. Silica Coating of Ferromagnetic Iron Oxide Magnetic Nanoparticles Significantly Enhances Their Hyperthermia Performances for Efficiently Inducing Cancer Cells Death In Vitro. These researchers prepared bimetallic polyacrylic acid-coated Fe-Au core-satellite nanosystems to combine the magnetic and plasmonic properties of iron and gold nanoparticles in one core-shell. Finally, to selectively recognize the glycosylation profile of breast cancer cells, the nanoparticles were functionalized with lectin concanavalin A. Under external light irradiation, the resulting hybrid nanoparticles fully inhibited allograft solid tumor growth in murine models, thus demonstrating a great potential for combined magnetically assisted targeted delivery to tumor sites, tumor bioimaging, and treatment. The most stable formulation of coated nanoparticles presented an enhanced magnetic hyperthermia performance in water, and their specific absorption rate values increased by almost 1000 W/g SB Fe sb compared to bare Fe SB 3 sb O SB 4 sb nanoparticles. [Extracted from the article]

In recent years, much effort has been invested into developing multifunctional drug delivery systems to overcome the drawbacks of conventional carriers. Magnetic nanoparticles are not generally used as carriers but can be functionalised with several different biomolecules and their size can be tailored to present a hyperthermia response, allowing for the design of multifunctional systems which can be active in therapies. In this work, we have designed a drug carrier nanosystem based on Fe3O4 nanoparticles with large heating power and 4-amino-2-pentylselenoquinazoline as an attached drug that exhibits oxidative properties and high selectivity against a variety of cancer malignant cells. For this propose, two samples composed of homogeneous Fe3O4 nanoparticles (NPs) with different sizes, shapes, and magnetic properties have been synthesised and characterised. The surface modification of the prepared Fe3O4 nanoparticles has been developed using copolymers composed of poly(ethylene-alt-maleic anhydride), dodecylamine, polyethylene glycol and the drug 4-amino-2-pentylselenoquinazoline. The obtained nanosystems were properly characterised. Their in vitro efficacy in colon cancer cells and as magnetic hyperthermia inductors was analysed, thereby leaving the door open for their potential application as multimodal agents. [ABSTRACT FROM AUTHOR]

Dendritic cells (DCs)‐based tumor vaccines have the advantages of high safety and rapid activation of T cells, and have been approved for clinical tumor treatment. However, the conventional DC vaccines have some severe problems, such as poor activation of DCs in vitro, low level of antigen presentation, reduced cell viability, and difficulty in targeting lymph nodes in vivo, resulting in poor clinical therapeutic effects. In this research, magnetic nanoparticles Fe3O4@Ca/MnCO3 were prepared and used to actively and efficiently deliver antigens to the cytoplasm of DCs, promote antigen cross‐presentation and DC activation, and finally enhance the cellular immune response of DC vaccines. The results show that the magnetic nanoparticles can actively and quickly deliver antigens to the cytoplasm of DCs by regulating the magnetic field, and achieve cross‐presentation of antigens. At the same time, the nanoparticles degradation product Mn2+ enhanced immune stimulation through the interferon gene stimulating protein (STING) pathway, and another degradation product Ca2+ ultimately promoted cellular immune response by increasing autophagy. The DC vaccine constructed with the magnetic nanoparticles can more effectively migrate to the lymph nodes, promote the proliferation of CD8+ T cells, prolong the time of immune memory, and produce higher antibody levels. Compared with traditional DC vaccines, cytoplasmic antigen delivery with the magnetic nanoparticles provides a new idea for the construction of novel DC vaccines. [ABSTRACT FROM AUTHOR]

Magnetic Fe3O4 nanoparticles (MNPs) have great potential for nucleic acid separation, detection, and delivery. MNPs are considered a valuable tool in biomedicine due to their cost-effectiveness, stability, easy surface functionalization, and the possibility of the manipulations under a magnetic field. Herein, the synthesis of magnetic nylon 6 nanocomposites (MNPs@Ny6) was investigated. Transmission electron microscopy (TEM) was used for morphology and size analysis. A new method of UV-induced immobilization of oligonucleotides on MNPs@Ny6 for nucleic acid magnetic separation was proposed. MNPs@Ny6 shows a high oligonucleotide binding capacity of 2.2 nmol/mg with 73.3% loading efficiency. The proposed system has been applied to analyze model mixtures of target RNA on the total yeast RNA background. The RNA target isolation efficiency was 60% with high specificity. The bind RNA release was 88.8% in a quantity of 0.16 nmol/mg. The total RNA capture efficiency was 53%. Considering this, the MNPs@Ny6 is an attractive candidate for nucleic acids-specific magnetic isolation. [ABSTRACT FROM AUTHOR]

This review tries to summarize the purpose of steadily developing surface-functionalized nanoparticles for various bio-applications and represents a fascinating and rapidly growing field of research. Due to their unique properties—such as novel optical, biodegradable, low-toxicity, biocompatibility, size, and highly catalytic features—these materials are considered superior, and it is thus vital to study these systems in a realistic and meaningful way. However, rapid aggregation, oxidation, and other problems are encountered with functionalized nanoparticles, inhibiting their subsequent utilization. Adequate surface modification of nanoparticles with organic and inorganic compounds results in improved physicochemical properties which can overcome these barriers. This review investigates and discusses the iron oxide nanoparticles, gold nanoparticles, platinum nanoparticles, silver nanoparticles, and silica-coated nanoparticles and how their unique properties after fabrication allow for their potential use in a wide range of bio-applications such as nano-based imaging, gene delivery, drug loading, and immunoassays. The different groups of nanoparticles and the advantages of surface functionalization and their applications are highlighted here. In recent years, surface-functionalized nanoparticles have become important materials for a broad range of bio-applications. [ABSTRACT FROM AUTHOR]