Nanoparticle Materials Research Articles

Dextran-coated Fe3 O4 Nanoparticles for Hyperthermia Therapy Application

In the present work, nanocrystals of magnetite were prepared by alkaline precipitation. The precursor used for synthesis was ferrous chloride only and the reaction was carried out in absence of any oxidant. Dextran is a material with excellent biocompatibility, water solubility and low cytotoxicity. Hence it was chosen as a potential coating material for the magnetic nanoparticles (MNPs). Both bare and coated MNPs (Fe3O4 and D- Fe3O4) showed particle size of diameter 20.8±4.1 nm and 16.3±3.2 nm, respectively. The magnetization values of both the MNPs were 53.62 emu/g and 47.86 emu/g at room temperature, respectively. The negligible coercivity and remanence values at room temperature implied superparamagnetic behaviour of the MNPs. Zeta potential of both bare and coated nanoparticles showed higher colloidal stability of coated nanoparticles than the bare one at a pH range of 2-10. The MNPs are studied for their heating induction abilities at 167.6 Oe, 251.4 Oe and 335.2 Oe (equivalent to 13.3, 20.0 and 26.7 kA m-1, respectively), in order to use them in magnetic fluid hyperthermia therapy. At 335.2 Oe, DFe 3O4 showed maximum Specific Absorption Rate (SAR) of 120.25 W/g, while bare MNPs showed SAR of 79.32 W/g. Both the particles had no cytotoxic effect on L929 cell line showing their strong possibility to be used for in vivo applications. The further work is in the process.

Next-generation materials for RNA-lipid nanoparticles: lyophilization and targeted transfection.

RNA, including mRNA, siRNA and miRNA, is part of a new class of patient treatments that prevent and treat several diseases. As an alternative to DNA therapy using plasmid DNA, RNA functions in the cellular cytosol, avoiding the potential risks of insertion into patient genomes. RNA drugs, including mRNA vaccines, need carrier materials for delivery into the patient's body. Several delivery carriers of mRNA, such as cationic polymers, lipoplexes, lipid-polymer nanoparticles and lipid nanoparticles (LNPs), have been investigated. For clinical applications, one of the most commonly selected types of RNA delivery carrier is LNPs, which are typically formed with (a) ionizable lipids, which bind to RNA; (b) cholesterol for stabilization; (c) phospholipids to form the LNPs; and (d) polyethylene glycol-conjugated lipids to prevent aggregation and provide stealth characteristics. Most RNA-LNP research has been devoted to achieving highly efficient RNA expression in vitro and in vivo. It is also necessary to study the extended storage of RNA-LNPs under mild conditions. One of the most efficient methods to store RNA-LNPs for a long time is to prepare freeze-dried (lyophilized) RNA-LNPs. Future research should include investigating LNP materials for the development of freeze-dried RNA-LNPs using optimal lipid components and compositions with optimal cryoprotectants. Furthermore, the development of sophisticated RNA-LNP materials for targeted transfection into specific tissues, organs or cells will be a future direction in the development RNA therapeutics. We will discuss the prospects for the development of next-generation RNA-LNP materials.

Superparamagnetic Iron Oxide Nanoparticles [SPION] and its Diversified Applications in the Medical Field: A Mini-Review

Late 21st century, extensive research has been carried out on nanoparticles due to their significant role in a supercapacitor, energy storage, sensing, catalysis, green gas production, and photocatalysis due to their semiconductor behavior, costeffective and simple methodology. The utilization of nanoparticle (NP) material provides numerous advantages in biomedical applications due to its unique properties. Superparamagnetic iron oxide nanoparticles (SPIONs) have been recognized in numerous fields including nanobiotechnology, biomedical engineering, and many other fields for their inestimable applications. Superparamagnetic properties and the smaller size of SPIONs are the major reasons for its utilization in various fields. In this study, we focused on different roots to synthesize the ION Super Paramagnetic Iron oxide nanoparticles (SPION), and biomedical applications due to their non-toxic in biological systems.

Challenges and opportunities for SERS in the infrared: materials and methods.

In the wake of a global, heightened interest towards biomarker and disease detection prompted by the SARS-CoV-2 pandemic, surface enhanced Raman spectroscopy (SERS) positions itself again at the forefront of biosensing innovation. But is it ready to move from the laboratory to the clinic? This review presents the challenges associated with the application of SERS to the biomedical field, and thus, to the use of excitation sources in the near infrared, where biological windows allow for cell and through-tissue measurements. Two main tackling strategies will be discussed: (1) acting on the design of the enhancing substrate, which includes manipulation of nanoparticle shape, material, and supramolecular architecture, and (2) acting on the spectral collection set-up. A final perspective highlights the upcoming scientific and technological bets that need to be won in order for SERS to stably transition from benchtop to bedside.

Multi-color luminescence and anticounterfeiting application of upconversion nanoparticle.

Multi-color luminescence materials are important in the illumination, solid-state three-dimensional display, information storage, biological labelling and anticounterfeiting fields. Herein, we designed a novel core-shell structure upconversion nanoparticle (UCNP) material (NaYF4) with lanthanide ion doping to achieve multi-color luminescence under a single NIR excitation laser. Different from the typical single-sensitizer materials, the core-shell structure utilizes Nd3+, Yb3+, Tm3+ and Er3+ ions to obtain tuning of the color and brightness. The doping of Nd3+ ions enhances the weak color (red) light source to maintain the light color balance. Benefiting from the color adjustment of the sensitizers and the change of the core-shell coating, bright-white emission and flexible color emission from red to green, cyan and blue can be achieved via the diverse doped rare earth ions in a single UCNP under continuous-wave laser excitation (980 nm). Simultaneously, the emission color of the UCNPs can change with the intensity of the excitation light source and the wavelength. The bright-white emission can be used for lighting displays, and the flexible full-color emission can be applied in the anticounterfeiting and information storage fields.

Enzyme assembly on nanoparticle scaffolds enhances cofactor recycling and improves coupled reaction kinetics.

Enzyme activity can be many times enhanced in configurations where they are displayed on a nanoparticle (NP) and this same format sometimes even provides access to channeling phenomena within multienzyme cascades. Here, we demonstrate that such enhancement phenomena can be expanded to enzymatic cofactor recycling along with the coupled enzymatic processes that they are associated with. We begin by showing that the efficiency of glucose driven reduction of nicotinamide adenine dinucleotide (NAD+ → NADH) by glucose dehydrogenase (GDH) is enhanced ca. 5-fold when the enzyme is displayed on nanocrystalline semiconductor quantum dots (QDs) which are utilized as prototypical NP materials in our experimental assays. Coupling this enzymatic step with NADH-dependent lactate dehydrogenase (LDH) conversion of lactate to pyruvate also increases the latter's rate by a similar amount when both enzymes were jointly incorporated into self-assembled QD-based nanoclusters. Detailed agarose gel mobility assays and transmission electron microscopy imaging studies confirm that both tetrameric enzymes assemble to and crosslink the QDs into structured nanoclusters via their multiple-pendant terminal (His)6 sequences. Unexpectedly, control experiments utilizing blocking peptides to prevent enzyme-crosslinking of QDs resulted in even further enhancement of individual enzyme on-QD kinetic activity. This activity was also probed revealing that 200-fold excess peptide/QD addition enhanced individual GDH and LDH on-QD kcat a further 2- and 1.5×, respectively, above that seen just by QD display to a maximum of ∼10-fold GDH enhancement. The potential implications for how these enzyme kinetics-enhancing phenomena can be applied to single and multi-enzyme cascaded reactions in the context of cofactor recycling and cell-free synthetic biology are discussed.

The Impact of Gold Nanoparticles Synthesized by Essential Oil of Lemon and Plasma Jet Scheme on Growth Inhibition of Breast Cancer Cells

Gold nanoparticles (AuNPs) have gained significance due to their size and shape. The current study aimed to prepare AuNPs by using green - plasma jet and calculate the cellular toxicity of those manufactured nanomaterials. Aqueous gold tetrachloride salts (HAuCl<sub>4</sub>·4H<sub>2</sub>O) and essential oil of lemon peels in different ratios (0:10, 1:9, 2:8, and 3:7) were used to produce AuNPs. The synthesized green-prepared gold was characterized by ultraviolet-visible (UV-vis), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). UV-vis spectrum showed the highest absorption at 540 nm, and the patterns of XRD at the ratio (2:8) showed four peaks occurred at peaks at 2θ = 38.1, 44.3, 64.5, and 77.98. FESEM study illustrated that the AuNPs particle sizes range between (38-76 nm). The cell toxicity results have shown the effectiveness of the green synthesized AuNPs on the breast cancer (AMJ13) cell line. The breast cancer (AMJ13) cell line is found to be more inhibited when the concentration of AuNPs reaches 100%. According to the findings, creating nanoparticle materials for the therapy of breast cancer cells using green-cold plasma is a potential technique.

Liposome Nanoparticles as a Novel Drug Delivery System for Therapeutic and Diagnostic Applications.

Liposome nanoparticles (LNPs), as a promising platform in drug delivery, combine the advantages of both liposomes and inorganic/organic nanoparticles into a single system. Both liposomes and nanoparticles have demonstrated optimized drug efficacy in the clinic. LNPs are proven to be multifunctional systems and thus utilized in various research applications (e.g., spatiotemporal control of drug release, hyperthermia, photothermal therapy, and biological imaging). The type of nanoparticles involved in LNPs largely affects the features of LNPs. Besides, diverse nanoparticles enable liposomes to overcome the defects such as poor stability, few functions, and rapid elimination from blood circulation. In this review, multiple nanoparticles materials and further prepared LNPs as well as their structure, physicochemical properties, manipulation and the latest applications in biomedical field are introduced. Future directions in advancing of LNPs are also discussed in the end.

Magnetized Tri-hybrid Nanofluids flow with binary Chemical Reaction and activation Energy through the porous Surfaces

Hybrid nanofluids are important to researchers because of their industrial applications due to their high heat transfer rates. Tri hybrid different types of nanoparticles are discussed here with Newtonian fluids under the effect of MHD. The most important chemical reaction associated with mass transfer and activation energy parameters hasbeen discussed in detail. The current research focuses on two-dimensional fluids with heat transfer enhancement flowing over a porous surface. The mathematical modeling of the problem, as well as empirical relations for nanoparticle materials, is expressed as PDEs, which are then translated into ODEs using appropriate variables. The Runge–Kutta and shooting methods are combined to solve the problems of the created coupled differential system. Variations in nanoparticle volume fraction at the lower and upper walls of porous plates, as well as heat transfer rate measurements, are computed using controlling physical factors. The impact of flow-related variables on the axial, radial, and temperature components of velocity and temperature distribution is also assessed.

Pristine, carboxylated, and hybrid multi-walled carbon nanotubes exert potent antioxidant activities in in vitro-cell free systems

Multi-walled carbon nanotubes (MWCNTs) are tubular-shaped carbon allotropes, composed of multiple concentric graphene cylinders. The extended systems of conjugated double bonds, that MWCNTs are constituted by, provide them with high electron affinities, enabling them to act as electron donors or acceptors. Consequently, their potential biomedical applications, as synthetic antioxidant agents, are of particular interest. Based on the above, the purpose of the present study was to evaluate the intrinsic antioxidant properties of pristine and carboxylated MWCNTs, as well as of novel hybrid nanocomposites of MWCNTs and inorganic nanoparticles. To this end, after the synthesis and characterization of MWCNTs, their antiradical, reducing, and antigenotoxic properties were assessed in cell-free assays, using a methodological approach that has been recently proposed by our research group. According to our results, most of the tested MWCNTs exhibited strong antioxidant activities. More elaborately, the hybrid material of MWCNTs and ferrous oxide nanoparticles, i.e., CNTs@Fe3O4, showed robust scavenging capacities in all free-radical scavenging assays examined. As regards reducing properties, the pristine MWCNTs, i.e., CNTs-Ref, exhibited the greater electron donating capacity. Finally, in terms of antigenotoxic properties, the hybrid material of MWCNTs and silicon carbide nanoparticles, i.e., CNTs@SiC, exhibited potent ability to inhibit the formation of peroxyl radicals, thus preventing from the oxidative DNA damage. Conclusively, our findings suggest that the MWCNTs of the study could be considered as promising broad-spectrum antioxidants, however, further investigations are required to evaluate their toxicological profile in cell-based and in vivo systems.

Developing an Endoscope Lens with Anti-Fogging and Anti-Fouling Properties using Nanoparticle Materials

Endoscopes are widely used in clinical settings. Gastric endoscopes in particular are useful for detecting early-stage gastric cancers and polyp removal. During polyp removal or other simple surgical procedures, however, the spatter of blood and bodily fluids resulting from excision of the affected areas can fog the endoscope lens. Condensation caused by temperature differences between the instrument interior and exterior can also affect image clarity. Any obstruction of the field of view during the surgical procedure must be addressed by removing the endoscope and cleaning the lens; however, doing so prolongs the time required for the procedure, makes it more invasive, and increases patient burdens. Drawing on biomimicry principles, we developed an endoscope lens with anti-fogging and anti-fouling features. This paper reports our results.

CFD simulation and optimization of natural convection in a vertical annulus with nanofluids

Numerical studies have been performed to examine the effect of base fluid, size, and constructive material of nanoparticles on natural convection heat transfer of nanofluids inside a vertical annulus using a finite volume method. The simulations are performed at a constant heat flux of 10,000 W/m2 and a volume fraction of nanoparticles of 0.03. Three controllable input parameters, i.e., size of nanoparticle (13 nm, 36 nm, and 59 nm), nanoparticles material (Copper, Aluminium oxide, and titanium dioxide), and base fluids (Water, Ethylene glycol, and Ethanol), were considered for the study. Their effect on four output responses, viz. heat transfer coefficient (HTC), Nusselt number (Nu), rate of mass flow (MFR), and Reynolds number (Re), was investigated using Taguchi's L27 orthogonal array. As a novelty, the study is further extended through Multi-response optimization. Two multi-criteria decision making (MCDM) methods namely Criteria Importance through Inter criteria Correlation (CRITIC) and weighted Aggregated Sum Product Assessment (WASPAS) are implemented to determine optimal setting of the input parameters that yield optimal multiple responses. The optimum combination of the input parameters, which maximizes the output responses simultaneously, is found as A2B1C1 (i.e., Particle size = 36 nm, constructive material of nanoparticles as copper, and base fluid as water). It is also concluded that the base fluids have the maximum influence on the heat transfer rate, followed by nanoparticle size and constructive materials.

Synthesis of Organic Semiconductor Nanoparticles with Different Conformations Using the Nanoprecipitation Method.

In recent years, nanoparticulate materials have aroused interest in the field of organic electronics due to their high versatility which increases the efficiency of devices. In this work, four different stable conformations based on the organic semiconductors P3HT and PC71BM were synthesized using the nanoprecipitation method, including blend and core-shell nanoparticles. All nanoparticles were obtained free of surfactants and in aqueous suspensions following the line of ecologically correct routes. The structural and optoelectronic properties of the nanoparticles were investigated by dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-visible absorption spectroscopy and UV-visible photoluminescence (PL). Even in aqueous media, the blend and core-shell nanoparticles exhibited a greater light absorption capacity, and these conformations proved to be effective in the process of dissociation of excitons that occurs at the P3HT donor/PC71BM acceptor interface. With all these characteristics and allied to the fact that the nanoparticles are surfactant-free aqueous suspensions, this work paves the way for the use of these colloids as a photoactive layer of organic photovoltaic devices that interface with biological systems.

TİTANYUM DİOKSİT(TiO2) NANOPARTİKÜL MADDELERİN EVSEL ATIKSULAR ÜZERİNE UYGULANMASI: KİRLETİCİLERİN GİDERİMİ

Titanium is the ninth most abundant element in the earth's crust and is usually found in minerals such as rutile, ilmenite, and sphene. Adsorption, photocatalysis, and advanced oxidation processes are used in water and wastewater treatment. Among these processes, photocatalysis has emerged as a safe, efficient, and environmentally friendly treatment process for the treatment of wastewater with high pollutant content. Titanium dioxide (TiO2) is widely used as a photocatalyst and adsorbent. Titanium dioxide nanoparticle material has been applied in various fields, including environmental water and wastewater treatment. In this study, treatment performance was investigated by using TiO2 nanoparticles for the removal of pollutants in domestic wastewater. System performance was evaluated in terms of chemical oxygen demand (COD), dissolved organic carbon (DOC), and total nitrogen (TN). Different adsorbent concentrations (50-200 mg/L) and reaction times (15-90 min) were investigated at pH 7.2 to determine optimum conditions. Optimum adsorption concentration and reaction time were found to be 50 mg TiO2/L and 60 minutes, respectively. COD, DOC, and TN removal efficiencies were observed as 80%, 30%, and 35%, respectively. The obtained results showed that the removal efficiency of COD and DOC from domestic wastewater of TiO2 nanoparticles is high.

N-Doped Carbon Nanotube Shell Encapsulating the NiFe Metal Core for Enhanced Catalytic Stability in Methanol Oxidation Reaction by the Structural Cooperation Mechanism.

Exploitation of high-efficiency catalysts toward methanol oxidation is a pivotal step to promote the commercialization of direct methanol fuel cells. Herein, a strategy is demonstrated to prepare nitrogen-doped carbon nanotubes with NiFe metal particles (NiFe@N-CNT) as the carrier material of Pt nanoparticles. Combining SEM and TEM, NiFe metal particles are fully encapsulated in N-CNTs, and they form the metal core and carbon nanotube shell structure based on the structural cooperation mechanism. Surprisingly, the as-prepared Pt/NiFe@N-CNT catalyst shows superior catalytic activity (1023 mA mg-1Pt) compared to commercial Pt/C (392 mA mg-1Pt), Pt/Ni@N-CNT (331 mA mg-1Pt), and Pt/Fe@N-CNT (592 mA mg-1Pt). After 1000 cycles, Pt/NiFe@N-CNT maintains the optimal catalytic activity (588 mA mg-1Pt), and its mass activity loss is 42.5%, which is better than those of commercial Pt/C (64.0%), Pt/Ni@N-CNT (67.7%), and Pt/Fe@N-CNT (59.6%) catalysts, indicating that the Pt/NiFe@N-CNT catalyst achieves excellent catalytic activity and stability, which stems chiefly from the homodispersed Pt nanoparticles and the generation of the metal core-carbon nanotube shell based on the structural cooperation mechanism. This study reports the facile construction of a metal core-carbon nanotube shell structure, which intrinsically ameliorates structural collapse of carrier material, thereby improving the catalytic stability of the Pt-based catalyst and broadening the view for design of other desire catalysts in methanol oxidation.

Continuous Flow Synthesis of Cd1-x Znx S and CdS/ZnS Core/Shell Semiconductor Nanoparticles by MicroJet Reactor Technology.

From aqueous precursor solutions of metal salts and sodium sulfide using MicroJet Reactor (MJR) technology Cd1-x Znx S and CdS/ZnS core/shell semiconductor nanoparticles were synthesized. The MJR approach represents an automated, continuous, flexible and scalable route for nanoparticle synthesis, providing a tight control over process parameters and thus simple size, shape and composition control. Since particle sizes below the excitonic Bohr radius were obtained by MJR, the nanoparticulate materials exhibit quantum confinement effects. By varying the precursor ratio the band gap of Cd1-x Znx S Quantum Dots (QDs) could be targeted from 3.1 to 3.6 eV. CdS/ZnS core/shell QDs were prepared by enclosing CdS particles from MJR with ZnS produced by thermal decomposition of a Zn-MPA complex. Adjustment of the shell thickness increased the photoluminescence intensity by 43 %. Synthesis of ternary sulfides in the form of core/shell particles broadens the spectrum of materials accessible by MJR and demonstrates the extraordinary flexibility of the technology.

Chitosan nanoparticles: Current aspects

Nanoparticles are currently becoming one of the important parts for various segments. Much more process/application becomes effective or more economical and time-saving because of nanoparticles. Polymers with distinct characteristics are widely used but nature-origin polymer has important properties that make a polymeric material for nanoparticles. Many methods were successfully evaluated to prepare chitosan nanoparticles for loading various compounds including ionotropic gelation, micelles, and emulsification methods. In this article, we have reviewed the current aspects made-up of chitosan nanoparticles. Chitosan nanoparticles have an application to improve bioavailability, controlled release of the loaded drug also increases cellular uptake and targeting to cancer cells, stabilization of proteins, and enhanced the effectivity of anti-microbial agents. In agriculture, chitosan nanoparticles are used for herbicides, insecticides, and pesticide loading to improve the cultivation of crops and are used in food packaging. Chitosan nanoparticles also have wide applications as implant and therapeutic agent.

Orally administered docetaxel-loaded chitosan-decorated cationic PLGA nanoparticles for intestinal tumors: formulation, comprehensive in vitro characterization, and release kinetics.

Intestinal cancers are the third most lethal cancers globally, beginning as polyps in the intestine and spreading with a severe metastatic tendency. Chemotherapeutic drugs used in the treatment of intestinal tumors are usually formulated for parenteral administration due to poor solubility and bioavailability problems. Pharmaceutically, clinical failure due to a drug's wide biodistribution and non-selective toxicity is one of the major challenges of chemotherapy. In addition, parenteral drug administration in chronic diseases that require long-term drug use, such as intestinal tumors, is challenging in terms of patient compliance and poses a burden in terms of health economy. Especially in the field of chemotherapy research, oral chemotherapy is a subject that has been intensively researched in recent years, and developments in this field will provide serious breakthroughs both scientifically and socially. Development of orally applicable nanodrug formulations that can act against diseases seen in the distant region of the gastrointestinal tract (GIT), such as intestinal tumor, brings with it a series of difficulties depending on the drug and/or GIT physiology. The aim of this study is to develop an oral nanoparticle drug delivery system loaded with docetaxel (DCX) as an anticancer drug, using poly(lactic-co-glycolic acid) (PLGA) as nanoparticle material, and modified with chitosan (CS) to gain mucoadhesive properties. In this context, an innovative nanoparticle formulation that can protect orally administered DCX from GIT conditions and deliver the drug to the intestinal tumoral region by accumulating in mucus has been designed. For this purpose, DCX-PLGA nanoparticles (NPs) and CS/DCX-PLGA NPs were prepared, and their in vitro characteristics were elucidated. Nanoparticles around 250-300 nm were obtained. DCX-PLGA NPs had positive surface charge with CS coating. The formulations have the potential to deliver the encapsulated drug to the bowel according to the in vitro release studies in three different simulated GIT fluids for approximately 72 h. Mucin interaction and penetration into the artificial mucus layer were also investigated in detail, and the mucoadhesive and mucus-penetration characteristics of the formulations were examined. Furthermore, in vitro release kinetic studies of the NPs were elucidated. DCX-PLGA NPs were found to be compatible with the Weibull model, and CS/DCX-PLGA NPs were found to be compatible with the Peppas-Sahlin model. Within the scope of in vitro cytotoxicity studies, the drug-loaded NPs showed significantly higher cytotoxicity than a DCX solution on the HT-29 colon cell line, and CS/DCX-PLGA showed the highest cytotoxicity (p < 0.05). According to the permeability studies on the Caco-2 cell line, the CS/DCX-PLGA formulation increased permeability by 383% compared to free DCX (p < 0.05). In the light of all results, CS/DCX-PLGA NPs can offer a promising and innovative approach as an oral anticancer drug-loaded nanoformulation for intestinal tumors.

The SLP estimation of the nanoparticle systems using size-dependent magnetic properties for the magnetic hyperthermia therapy

Magnetic Nanoparticle hyperthermia (MNH) is one of the hyperthermia therapy in which temperature gain is achieved through magnetic nanoparticles in the tumor tissue/targeted region. The key parameters for efficient heating in MNH are magnetic nanoparticle (MNPs) properties, its size & materials, and magnetic field parameters (amplitude and frequency). Thus, the present study investigates the effects of these parameters on heat generation during MNH. In this study, a comparison of heat generation by three nanoparticle systems (CoFe2O4, Fe3O4, and MnFe2O4) and its dependency on size & magnetic field parameters is theoretically investigated. The quantification of specific loss power (SLP) of nanoparticle systems depending on its size-dependent saturation magnetization (MS) and the anisotropy constant (Keff). of nanoparticles has been done in this work. Correlations for MS and Keff based on the previously reported experimental data have been established for considered MNP systems. The comparisons show that SLP estimation using MNP size-dependent saturation magnetization (MS) (Fig. 4) are closer to the experimentally reported values of SLP for all considered MNP systems (CoFe2O4, Fe3O4, MnFe2O4) in comparison to SLP estimated by fixed values of saturation magnetization (MS) and anisotropy constant (Keff). Results show that dissipated power reaches a peak at a certain particle size (DO). However, the (DO) varies with the magnetic field frequency and amplitude. It decreases as the frequency increases at a particular field amplitude. In addition, the SLP increment ceases after a certain frequency (fO) that is around 500 kHz for considered MNP systems. On the other hand, the SLP continuously increases with an increase in field amplitude. Thus this work incorporates the empirical correlations as well as experimental data to predict the SLP for three magnetic nanoparticle systems generally utilized in the MNH.

Effects of Fe3O4 Magnetic Nanoparticle Functionalization with Ionic Liquids and a Double-Chained Surfactant on the Pretreatment of Plasma Samples during Drug Extraction.

Ionic liquids (ILs), also known as "designer solvents," comprise a large group of compounds that can improve overall sample preparation performance due to their unique physical and chemical properties. Some of them have a comparable structure to surfactants, which can be also considered as effective extraction solvents. In this study, nine different ILs and a double-chained surfactant were investigated as potential coating materials for iron oxide-based nanoparticles (NPs) used in the pretreatment of human plasma samples. Various methods of synthesizing and functionalizing NPs were employed in fabricating the magnetic sorbents, with the physicochemical properties of the resultant extraction phases (i.e., naked NPs, NPs coated with silica, and NPs coated with silica and selected IL or surfactant) being characterized via X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TG), and transmission electron microscopy (TEM). The effectiveness of the developed NP-based extraction phases was tested by applying them for the extraction of epirubicin hydrochloride (EPI) from plasma samples, followed by analysis via liquid chromatography with fluorescence detection (LC-FL). The results showed that NPs coated with both silica and IL or silica and surfactant provided significantly higher extraction efficiency compared to naked NPs and NPs coated solely with silica. Additionally, the findings also revealed that the adsorption of analytes depends not only on the coating procedure but also on the type of coating material used to functionalize the NPs. Among the tested structures, didodecyldimethylammonium bromide provided the best performance for the functionalization of NP sorbents previously coated with silica.