One-pot, exchange-free, room-temperature synthesis of sub-10 nm aqueous, noninteracting, and stable zwitterated iron oxide nanoparticles

A review on synthesis, capping and applications of superparamagnetic magnetic nanoparticles

Magnetic nanoparticles (MNPs) have garnered significant attention from researchers due to their numerous technologically significant applications in diverse fields, including biomedicine, diagnostics, agriculture, optics, mechanics, electronics, sensing technology, catalysis, and environmental remediation. The superparamagnetic nature of MNP is exploited for many applications and remains fascinating to study many fundamental phenomena. The uniqueness of this review is that it gives an in-depth review of different synthesis approaches adopted for preparing magnetic nanoparticles and nanoparticle formation mechanisms, functionalizing them with different capping agents, and applying different functionalized magnetic nanoparticles. The important synthesis techniques covered include coprecipitation, microwave-assisted, sonochemical, sol-gel, microemulsion, hydrothermal/solvothermal, thermal decomposition, and mechano-chemical synthesis. Further, the advantages and disadvantages of each technique are discussed, and tables show important results of prepared particles. Other aspects covered in this review are the dispersion of magnetic nanoparticles in the continuous matrix, the influence of surface capping on high-temperature thermal stability, the long-term stability of ferrofluids, and applications of functionalized magnetic nanoparticles. For effective utilization of the ferrite nanoparticles, it is essential to formulate thermally and colloidally stable magnetic nanoparticles with desired magnetic properties. Capping enhances the phase transition temperature and long-term colloidal stability. Magnetic nanoparticles capped or functionalized with specific binding species, specific components like drugs, or other functional groups make them suitable for applications in biotechnology/biomedicine. Recent studies reveal the tremendous scope of MNPs in therapeutics and theranostics. The requirements for nanoparticle size, morphology, and physio-chemical properties, especially magnetic properties, functionalization, and stability, vary with applications. There are also challenges for precise size control and the cost-effective production of nanoparticles in large quantities. The review should be an ideal material for researchers working on magnetic nanomaterials and an excellent reference for freshers.

Progress in ultrasmall ferrite nanoparticles enhanced T1 magnetic resonance angiography

Contrast-enhanced magnetic resonance angiography (CE-MRA) plays a critical role in diagnosing and monitoring various vascular diseases. Achieving high-sensitivity detection of vascular abnormalities in CE-MRA depends on the properties of contrast agents. In contrast to clinically used gadolinium-based contrast agents (GBCAs), the new generation of ultrasmall ferrite nanoparticles-based contrast agents have high relaxivity, long blood circulation time, easy surface functionalization, and high biocompatibility, hence showing promising prospects in CE-MRA. This review aims to comprehensively summarize the advancements in ultrasmall ferrite nanoparticles-enhanced MRA for detecting vascular diseases. Additionally, this review also discusses the future clinical translational potential of ultrasmall ferrite nanoparticles-based contrast agents for vascular imaging. By investigating the current status of research and clinical applications, this review attempts to outline the progress, challenges, and future directions of using ultrasmall ferrite nanoparticles to drive the field of CE-MRA into a new frontier of accuracy and diagnostic efficacy.

Pharmacokinetics of magnetic iron oxide nanoparticles for medical applications

Magnetic iron oxide nanoparticles (MNPs) have been under intense investigation for at least the last five decades as they show enormous potential for many biomedical applications, such as biomolecule separation, MRI imaging and hyperthermia. Moreover, a large area of research on these nanostructures is concerned with their use as carriers of drugs, nucleic acids, peptides and other biologically active compounds, often leading to the development of targeted therapies. The uniqueness of MNPs is due to their nanometric size and unique magnetic properties. In addition, iron ions, which, along with oxygen, are a part of the MNPs, belong to the trace elements in the body. Therefore, after digesting MNPs in lysosomes, iron ions are incorporated into the natural circulation of this element in the body, which reduces the risk of excessive storage of nanoparticles. Still, one of the key issues for the therapeutic applications of magnetic nanoparticles is their pharmacokinetics which is reflected in the circulation time of MNPs in the bloodstream. These characteristics depend on many factors, such as the size and charge of MNPs, the nature of the polymers and any molecules attached to their surface, and other. Since the pharmacokinetics depends on the resultant of the physicochemical properties of nanoparticles, research should be carried out individually for all the nanostructures designed. Almost every year there are new reports on the results of studies on the pharmacokinetics of specific magnetic nanoparticles, thus it is very important to follow the achievements on this matter. This paper reviews the latest findings in this field. The mechanism of action of the mononuclear phagocytic system and the half-lives of a wide range of nanostructures are presented. Moreover, factors affecting clearance such as hydrodynamic and core size, core morphology and coatings molecules, surface charge and technical aspects have been described.

S, Prakash P, Nishad KV, Komath M, Nair BN, G. S. S. Amino acid inspired tunable superparamagnetic iron oxide (SPION) nanostructures with high magnetic hyperthermia potential for biofunctional applications

Amino acid inspired biocompatible and tunable magnetic SPION nanostructures with high saturation magnetization hyperthermia and biofunctional probe potential are shown.

The Role of Zwitterionic Materials in the Fight against Proteins and Bacteria

Zwitterionization of biomaterials has been heightened to a potent tool to develop biocompatible materials that are able to inhibit bacterial and non-specific proteins adhesion. This constitutes a major progress in the biomedical field. This manuscript overviews the main functionalization strategies that have been reported up to date to design and develop these advanced biomaterials. On this regard, the recent research efforts that were dedicated to provide their surface of zwitterionic nature are summarized by classifying biomaterials in two main groups. First, we centre on biomaterials in clinical use, concretely bioceramics, and metallic implants. Finally, we revise emerging nanostructured biomaterials, which are receiving growing attention due to their multifunctionality and versatility mainly in the local drug delivery and bone tissue regeneration scenarios.

Drug Delivery and Bone Infection

Bone infection represents greatest challenge in public health care with serious social and economic implications. The efforts of the scientific community are focused in the development of innovative and advanced biomaterials with anti-infective properties related to their non-fouling, bactericidal and/or antibiofilm capabilities. This chapter aims at thoroughly surveying the different approaches based on silica mesoporous materials (SMMs) for bone infection management. Bacteria repelling surfaces by zwitterionization process, bactericidal effect by implantable devices with antimicrobial local delivery agents and antibiofilm effect by more sophisticated systems based on targeted nanocarriers will be considered.

Design and preparation of bi-functionalized short-chain modified zwitterionic nanoparticles

An ideal nanomaterial for use in the bio-medical field should have a distinctive surface capable of effectively preventing nonspecific protein adsorption and identifying target bio-molecules. Recently, the short-chain zwitterion strategy has been suggested as a simple and novel approach to create outstanding anti-fouling surfaces. In this paper, the carboxyl end group of short-chain zwitterion-coated silica nanoparticles (SiO₂-ZWS) was found to be difficult to functionalize via a conventional EDC/NHS strategy due to its rapid hydrolysis side-reactions. Hence, a series of bi-functionalized silica nanoparticles (SiO₂-ZWS/COOH) were designed and prepared by controlling the molar ratio of 3-aminopropyltriethoxysilane (APTES) to short-chain zwitterionic organosiloxane (ZWS) in order to achieve above goal. The synthesized SiO₂-ZWS/COOH had similar excellent anti-fouling properties compared with SiO₂-ZWS, even in 50% fetal bovine serum characterized by DLS and turbidimetric titration. Subsequently, SiO₂-ZWS/COOH_5/1 was chosen as a representative and then demonstrated higher detection signal intensity and more superior signal-to-noise ratios compare with the pure SiO₂-COOH when they were used as a bio-carrier for chemiluminescence enzyme immunoassay (CLEIA). These unique bi-functionalized silica nanoparticles have many potential applications in the diagnostic and therapeutic fields.

STATEMENT OF SIGNIFICANCE

Reducing nonspecific protein adsorption and enhancing the immobilized efficiency of specific bio-probes are two of the most important issues for bio-carriers, particularly for a nanoparticle based bio-carrier. Herein, we designed and prepared a bi-functional nanoparticle with anti-fouling property and bio conjugation capacity for further bioassay by improving the short-chain zwitterionic modification strategy we have proposed previously. The heterogeneous surface of this nanoparticle showed effective anti-fouling properties both in model protein solutions and fetal bovine serum (FBS). The modified nanoparticles can also be successfully functionalized with a specific antibody for CLEIA assay with a prominent bio-detection performance even in 50% FBS. In this paper, we also investigated an unexpectedly fast hydrolysis behavior of NHS-activated carboxylic groups within the pure short-chain zwitterionic molecule that led to no protein binding in the short-chain zwitterion modified nanoparticle. Our findings pave a new way for the designing of high performance bio-carriers, demonstrating their strong potential as a robust platform for diagnosis and therapy.

Zwitterion-coated ultrasmall iron oxide nanoparticles for enhanced T1-weighted magnetic resonance imaging applications

We report a convenient strategy to prepare ultrasmall Fe₃O₄ nanoparticles (NPs) coated with zwitterion l-cysteine (Cys) for enhanced T₁-weighted magnetic resonance (MR) imaging applications. The formed Fe₃O₄-PEG-Cys NPs possess antifouling properties, good r₁ relaxivity, excellent cytocompatibility and hemocompatibility, and can be used as a contrast agent for enhanced blood pool and tumor MR imaging.

Zwitterionic ceramics for biomedical applications

Bioceramics for bone tissue regeneration, local drug delivery and nanomedicine, are receiving growing attention by the biomaterials scientific community. The design of bioceramics with improved surface properties able to overcome clinical issues is a great scientific challenge. Zwitterionization of surfaces has arisen as a powerful alternative in the design of biocompatible bioceramics capable to inhibit bacterial and non-specific protein adsorption, which opens up new insights into the biomedical applications of these materials. This manuscript reviews the different approaches reported up to date for the synthesis and characterization of zwitterionic bioceramics with potential clinical applications.

STATEMENT OF SIGNIFICANCE

Zwitterionic bioceramics are receiving growing attention by the biomaterials scientific community due to their great potential in bone tissue regeneration, local drug delivery and nanomedicines. Herein, the different strategies developed so far to synthesize and characterize zwitterionic bioceramics with potential clinical applications are summarized.

Manipulating the dimensional assembly pattern and crystalline structures of iron oxide nanostructures with a functional polyolefin

Controlled crystalline structures (α- and γ-phase) and assembly patterns (1-D, 2-D and 3-D) were achieved in the synthesized iron oxide (Fe2O3) nanoparticles (NPs) using polymeric surfactant-polypropylene grafted maleic anhydride (PP-g-MA) with different concentrations. In addition, the change of the crystalline structure from the α- and γ-phase also led to the significantly increased saturation magnetization and coercivity.

Surface Modification for Superhydrophilicity and Underwater Superoleophobicity: Applications in Antifog, Underwater Self-Cleaning, and Oil-Water Separation

A facile yet effective surface modification strategy for superhydrophilicity and underwater superoleophobicity was developed by silanization of zwitterionic sulfobetaine silane (SBSi) on oxidized surfaces. The coatings exhibit excellent wetting properties, as indicated by static contact angles of <5°, and long-term stability under exposure to heat and UV irradiation. The SBSi-modified surfaces were employed for applications in antifog, self-cleaning, and oil-water separation. The SBSi glasses retained their optical transmittance because of the rapid formation of coalesced water thin films on surfaces in contact with water vapor and moisture. In addition, the underwater-oil contact-angle measurements verified the underwater superoleophobicity of the zwitterionic SBSi coatings. The oil spills on the SBSi coating could be readily removed in contact with water to realize the self-cleaning property. Besides, we modified stainless steel wire meshes with SBSi for oil-water separation. The optimal oil recovery rate for the oil-water mixtures reached >99.5% when using the SBSi-coated meshes with a pore size of 17 μm. More importantly, the water flux with modified meshes achieved 6.5 × 10(7) L/m(2)·h·bar, enabling gravity-driven and energy-saving separation. Consequently, we demonstrated the superhydrophilicity and underwater superoleophobicity of SBSi, offering promise in solving technological problems of interfacial fog, oil spills, and oil-water separation and thereby showing great potential in large-scale commercial applications.

Zwitterion-Coated Iron Oxide Nanoparticles: Surface Chemistry and Intracellular Uptake by Hepatocarcinoma (HepG2) Cells

Nanoparticles (NPs) have received much attention in recent years for their diverse potential biomedical applications. However, the synthesis of NPs with desired biodistribution and pharmacokinetics is still a major challenge, with NP size and surface chemistry being the main factors determining the behavior of NPs in vivo. Here we report on the surface chemistry and in vitro cellular uptake of magnetic iron oxide NPs coated with zwitterionic dopamine sulfonate (ZDS). ZDS-coated NPs were compared to similar iron oxide NPs coated with PEG-like 2-[2-(2-methoxyethoxy)ethoxy]acetic acid (MEEA) to investigate how surface chemistry affects their in vitro behavior. ZDS-coated NPs had a very dense coating, guaranteeing high colloidal stability in several aqueous media and negligible interaction with proteins. Treatment of HepG2 cells with increasing doses (2.5-100 μg Fe/mL) of ZDS-coated iron oxide NPs had no effect on cell viability and resulted in a low, dose-dependent NP uptake, inferior than most reported data for the internalization of iron oxide NPs by HepG2 cells. MEEA-coated NPs were scarcely stable and formed micrometer-sized aggregates in aqueous media. They decreased cell viability for dose ≥50 μg Fe/mL, and were more efficiently internalized than ZDS-coated NPs. In conclusion, our data indicate that the ZDS layer prevented both aggregation and sedimentation of iron oxide NPs and formed a biocompatible coating that did not display any biocorona effect. The very low cellular uptake of ZDS-coated iron NPs can be useful to achieve highly selective targeting upon specific functionalization.

Single- and multicompartment hollow polyelectrolyte complex microcapsules by one-step spraying

Polyelectrolyte complex microcapsules are prepared using a novel template- and surfactant-free method. The microcapsules are produced spontaneously by ultrasonically spraying a solution of complex into a hot water reservoir, which enhances diffusion and relaxation of the polymer. The size and wall thickness of the microcapsules are precisely controlled. Encapsulation of polymers and nanoparticles by mixing them with polyelectrolyte solutions is demonstrated.

Zwitterionic-coated "stealth" nanoparticles for biomedical applications: recent advances in countering biomolecular corona formation and uptake by the mononuclear phagocyte system

Nanoparticles represent highly promising platforms for the development of imaging and therapeutic agents, including those that can either be detected via more than one imaging technique (multi-modal imaging agents) or used for both diagnosis and therapy (theranostics). A major obstacle to their medical application and translation to the clinic, however, is the fact that many accumulate in the liver and spleen as a result of opsonization and scavenging by the mononuclear phagocyte system. This focused review summarizes recent efforts to develop zwitterionic-coatings to counter this issue and render nanoparticles more biocompatible. Such coatings have been found to greatly reduce the rate and/or extent of non-specific adsorption of proteins and lipids to the nanoparticle surface, thereby inhibiting production of the "biomolecular corona" that is proposed to be a universal feature of nanoparticles within a biological environment. Additionally, in vivo studies have demonstrated that larger-sized nanoparticles with a zwitterionic coating have extended circulatory lifetimes, while those with hydrodynamic diameters of ≤5 nm exhibit small-molecule-like pharmacokinetics, remaining sufficiently small to pass through the fenestrae and slit pores during glomerular filtration within the kidneys, and enabling efficient excretion via the urine. The larger particles represent ideal candidates for use as blood pool imaging agents, whilst the small ones provide a highly promising platform for the future development of theranostics with reduced side effect profiles and superior dose delivery and image contrast capabilities.

Folic acid-conjugated glucose and dextran coated iron oxide nanoparticles as MRI contrast agents for diagnosis and treatment response of rheumatoid arthritis

Coating superparamagnetic iron oxide (SPIO) with dextran increases the stability of the magnetic nanoparticles during blood circulation, yet this is accompanied by an increase in the particle size and the vascular permeability efficiency of the SPIO nanoparticles into the joints decreases. In our study, the thickness of the dextran coated onto SPIO (dex-SPIO) was optimized without affecting the magnetic quality of iron oxide by adding a suitable amount of glucose into the crystal growth process. To further improve the signal enhancement effect of this glucose and dextran coated SPIO (glu-dex-SPIO) for the detection of the inflammatory site of arthritis, folic acid (FA) was conjugated to glu-dex-SPIO. This FA glu-dex-SPIO was used as a negative contrast agent for MRI to visualize the antigen induce arthritis (AIA) model in rats using a 7 T MR scans. MR imaging revealed more significant differences between the synovium and surrounding tissues with FA glu-dex SPIO than when using the non-targeting glu-dex-SPIO over a long period of time (24 h) after intravenous injection. Moreover, the therapeutic efficacy of the cyclooxygenase 2 (COX-2) inhibitor treatment of the inflamed joints also could be confirmed by using FA glu-dex SPIO enhanced MRI, indicating that this type of nanoparticles could also have potential as a contrast agent for measuring the treatment response of rheumatoid arthritis.