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The grafting of a drug molecule, i.e., geldanamycin (GA) onto polyethyleneimine (PEI)-coated magnetic nanoparticle produces a novel composite, GA@Fe 3 O 4 –NH 2. The composite is confirmed by characterizations with FT-IR, Raman, SEM, EDS, VSM and TEM. Due to the high binding-affinity of GA with myosin heavy chain (MYH), GA@Fe 3 O 4 –NH 2 exhibits excellent adsorption performance towards myosin. Consequently, a solid-phase extraction procedure is established for highly efficient and selective separation of myosin from pig heart extract. At pH 6.0, an adsorption efficiency of 97.1 % is achieved for treating 100 μg mL−1 myosin (0.1 mL) with 0.1 mg GA@Fe 3 O 4 –NH 2 as adsorbent. The adsorption behavior of myosin onto GA@Fe 3 O 4 –NH 2 fits Langmuir model, corresponding to a theoretical adsorption capacity of 518.1 mg g−1. The adsorbed myosin can be readily recycled by the SDS solution (1 %, m/m) with an elution efficiency of 91.8 %. According to circular dichroism spectroscopy, the conformational changes of myosin during adsorption and elution are reversible. For practical application, myosin is successfully isolated from the pig left ventricular protein extract with GA@Fe 3 O 4 –NH 2 , and SDS-PAGE and LC-MS/MS showed that myosin had high purity and a total of 716 proteins could be identified. Significantly, Geldamycin-encapsulated magnetic nanoparticle for the separation of myosin well exploits the potential of the nanomaterials modified by drug molecules in the separation and purification of target proteins. [Display omitted] • GA@Fe 3 O 4 –NH 2 was obtained through intermolecular hydrogen bonds. • GA@Fe 3 O 4 –NH 2 exhibits selective adsorption for myosin due to the high binding-affinity of GA with myosin heavy chain. • GA@Fe 3 O 4 –NH 2 as a protein extractant has potential application value in scrofa heart proteomics. [ABSTRACT FROM AUTHOR]

The multifunctional NaYF 4 :Yb,Er@SiO 2 @Fe 3 O 4 with upconversion luminescence and superparamagnetic properties were obtained for imaging and phototherapy in the optical biological windows. [Display omitted] • The multifunctional nanoparticles with upconversion luminescence and superparamagnetic properties were synthesized. • The heat generation ability of the nanoparticles upon their irradiation with 808 nm and 880 nm laser light was obtained. • The multifunctional nanoconstruct suitable for imaging and phototherapy in the optical biological windows was obtained. Multifunctional opto-magnetic nanoparticles (NPs) with upconverting properties were designed for cancer detection and treatment. The upconversion was achieved from NaYF 4 doped by 20 %Yb and 2 % Er nanoparticles (UCNPs). The UCNPs were coated by a thin SiO 2 shell and decorated with 6 nm magnetic Fe 3 O 4 that resulted in the formation of NaYF 4 :Yb,Er@SiO 2 @Fe 3 O 4 multifunctional nanoplatform. The connection between UCNPs and Fe 3 O 4 NPs was proved by SEM, TEM, SQUID, absorption, and luminescence techniques. The specific absorption rate (SAR) values for prepared colloids were calculated for colloidal suspension of heterostructures after 808 and 880 nm laser irradiation as a function of lasers power. The highest conversion effectiveness was obtained for an 880 nm light source with 1600 mW (SAR = 87 W/g). The low MDA-MB-231 cells cytotoxicity of NaYF 4 :Yb,Er@SiO 2 @Fe 3 O 4 NPs was observed (up to 500 µg/ml). At the same time, a strong upconverting signal after 980 nm of excitation was observed from the sites of the cells without autofluorescence from its components. This phenomenon with relatively good SAR parameters suggested that multifunctional nanoconstructs for simultaneous cancer detection (imaging) and photothermal therapy have been successfully obtained. [ABSTRACT FROM AUTHOR]

A simple and sensitive homogeneous protein detection system is required for the early detection of biomarkers. Thermo-responsive magnetic particles (TM) have already been developed to achieve easy bound/free separation at the homogeneous protein detection system, but they are still limited owing to the requirement of secondary antibodies and negatively charged polymers, and it is challenging to control the TM aggregation behavior because of the size of the TM. Therefore, at new method to control TM aggregation behavior that is simple, easy, and highly sensitive is required. In this study, we developed a DNA aptamer-based TM assay as a simple protein detection system without additional secondary molecular recognition elements or negatively charged polymer. In the first attempt, a DNA aptamer was modified on the TM surface, and its aggregation behavior was monitored depending on the target molecule concentration. The TM aggregation rate during the heating process decreased depending on the amount of the DNA aptamer and increased depending on the target protein level. This suggests that the DNA aptamer prevented TM aggregation owing to its negative charge and achieved target protein detection owing to the cancellation of repulsion. Capturable aptamers were used in the TM assay to improve the sensitivity and limit of detection. The designed Capture DNA was modified on the TM surface, and the aptamer was captured in the presence of the target protein through a conformational change. Eventually, Capturable aptamer-based TM assay achieved a sub-nanomolar limit of detection and higher sensitivity than that of our initial investigation. Through this study and the ease of the DNA aptamer design, it was shown that the DNA aptamer-modified TM assay enabled the development of a simple and sensitive homogeneous protein detection system. • DNA aptamer-modified Thermo-responsible magnetic nanoparticle (TM) was designed. • TM aggregation was controlled by DNA modification. • Protein target binding to the modified DNA aptamer facilitated TM aggregation. • Capturable aptamer enhanced a detection limit due to its bound/free separation. • Capturable aptamer-based TM assay achieved sub-nanomolar or less detection limit. [ABSTRACT FROM AUTHOR]

The metal-organic framework (MOF) ZIF-8 has found extensive application in the medicinal and agricultural fields. This study aimed to immobilize the methyl parathion hydrolase (MPH) enzyme from Azohydromonas australica (Azau-MPH) within ZIF-8 using an in-situ synthesis method. Interestingly, the immobilized Azau-MPH (abbreviated as Azau-MPH@ZIF-8) exhibited enhanced thermostability and tolerability towards organic solvents compared to the free enzyme. Moreover, Azau-MPH@ZIF-8 retained more than 50% of its initial activity after six cycles, demonstrating its desirable reusability. To further improve the recyclability and catalytic activity of the immobilized enzyme, we introduced magnetic Fe 3 O 4 nanoparticles into the immobilization carrier. Notably, the resulting Azau-MPH@(Fe 3 O 4 @ZIF-8) biocomposite displayed superior catalytic activity and stability when compared to Azau-MPH@ZIF-8. In practical applications, we employed Azau-MPH@ZIF-8 for cyclic degradation of methyl parathion (20 mg/L) in cherries, and it exhibited exceptional degradation ability. Hence, both Azau-MPH@ZIF-8 and Azau-MPH@(Fe 3 O 4 @ZIF-8) hold great promise as valuable biodegradation tools against MP contamination. [ABSTRACT FROM AUTHOR]

Laccase is an efficient biocatalyst for oxidative polymerization of organic substrates. However, cost of enzyme preparation, low stability and residual protein diminish the efficiency of laccase mediated polymerization. In this work, a series of silicon dioxide coated ferroferric oxide magnetic nanoparticles were modified by different functional groups including γ-methacryloxypropyltrimethoxy, succinic anhydride, glutaraldehyde and polyethylene imine. Infrared spectra indicated the magnetic carriers have been successfully modified. Vibrating sample magnetometer (VSM) analysis revealed that all of these carriers showed high magnetic responsiveness after the surface functionalization. Laccase from Cerrena sp. HYB07 was then respectively immobilized covalently on these functionalized magnetic carriers. All the immobilized laccases displayed higher thermostability than free laccase and glutaraldehyde functionalized support (named FSNG) immobilized laccase showed better performance. These immobilized laccases all showed higher efficiency than free laccase for oxidative polymerization of catechol and hydroquinone. The immobilized laccases could be separated from the water insoluble polymerization products. The polymerization product of hydroquinone by FSNG immobilized laccase showed the average polymerization degree of the poly(hydroquinone) was six (DP=6). This work provided a comprehensive exploration of laccase immobilization on magnetic carrier for catalyzing polymerization of phenols. • A series of SiO 2 coated Fe 3 O 4 magnetic nanoparticles were modified by different functional groups. • Cerrena sp. laccase was respectively immobilized on the four functionalized carriers for comparative investigation. • Glutaraldehyde functionalized support FSNG showed the best performance than other supports for laccase immobilization. • FSNG immobilized laccase could efficiently catalyze polymerization of phenols. • The polymerization products of hydroquinone was structurally characterized. [ABSTRACT FROM AUTHOR]

The concern on the adverse impacts of electromagnetic (EM) pollution has continuously increased. Instead of using heavy metal sheet, this work aims to develop magnetic polymeric particles, that can easily be incorporated in coatings, for EM/ultraviolet-visible-near infrared (UV–Vis-NIR) shielding. By carefully design structure and key components, hollow magnetic (HoM) polyaniline (PANI) particles possessing a void encircled with magnetic nanoparticles dispersed in PANI semi-conductive shell were fabricated via the oxidative polymerization in emulsion system. By using ethyl benzene as a soft template and different surfactive dopants, i.e., sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and poly(sodium 4-styrenesulfonate) (PSS), the HoM-PANI particles (0.5–2 μm) with well-defined hollow structure, high magnetic loading (17–21%wt), and superparamagnetic properties were obtained. The particle size distribution, and magnetic loading were slightly affected by the reaction temperature, whereas molecular weight (M w) of the localized dopant considerably influenced on the levels of interparticle connectivity, and hence, the conductivity could be tailored. The water dispersible HoM-PANI particles could form opaque coating, and free-standing film. PSS with M w of 70 K and 1 M yielded the larger HoM-PANI particles and more opaque films than small dopant molecules. Void size was the determining effect on excellent opacity of the coating containing HoM-PANI dispersed in poly(vinyl alcohol) matrix against UV–Vis-NIR, and EM radiation. The ability to tune their optical properties, and electrical conductivity accomplished by designing the particle nanostructure, and doping/de-doping by localized dopants enables them the promising candidates for functional paint, and film for irradiation protection. • Hollow magnetic polyaniline (HoM-PANI) particles are fabricated via in situ polymerization in one pot. • By using surfactive dopants, HoM-PANI particles with high magnetic loading and large void were obtained. • HoM-PANI particles displayed water dispersibility and could be mixed with polar and non-polar polymer matrixes. • HoM-PANI particles could act as hybrid fillers for coating with UV-Vis-NIR/EMI SE. [ABSTRACT FROM AUTHOR]

• Three deterministic tools are used to assess oil adsorption capacity on functionalized MNP. • The LSSVM-CSA model outperforms other AI/ML models. • The most effective input parameters are oil concentration and MNP dosage. • The GEP model gives a correlation for oil adsorption predictions with high accuracy. • This research provides tips/guidelines for effective design of oil emulsion/water separation. Using magnetic nanoparticles (MNPs) has emerged as a promising solution to capture oil from emulsified oily wastewater due to their high oil adsorption capacity, low toxicity, and reusability. Various factors affect the oil adsorption process using MNPs; thus, optimization of the process is required to achieve higher oil adsorption capacity. Smart models based on artificial intelligence (AI) are becoming popular as advanced computational tools to assess the non-linear relationships of variables in complex processes. In this study, least squares support vector machines (LSSVM) hybridized with the coupled simulated annealing (CSA) algorithm, adaptive network-based fuzzy inference system (ANFIS), and optimization techniques such as gene expression programming (GEP) are used to predict the oil adsorption capacity as a target variable. Oil concentration, mixing time, and MNP dosage as effective parameters are selected as input variables. After conducting experiments, 149 data points are obtained, 80 % of which is used in the training process and the remaining 20 % for the testing step. The performances of the developed models are evaluated using statistical parameters, including the coefficient of determination ( R 2), mean percentage error (MPE), and mean absolute percentage error (MAPE). According to the results, ANFIS and LSSVM-CSA models have a better performance than the GEP model in estimating the oil adsorption capacity with higher values of R 2 (>0.99) and smaller relative errors (close to zero) for all training, testing, and total datasets. Detailed model evaluation and error analysis indicate that the LSSVM-CSA model predicts slightly better than ANFIS with the highest R 2 of 0.9921 and a very small MAPE = 3.7597 % over the total dataset. Although the developed GEP model shows an acceptable prediction with R 2 > 0.95, the higher distribution of relative errors of the developed model results in a larger MAPE. Moreover, the GEP model computational time is considerably greater than that of the other models. The relative importance analysis using Pearson's and Spearman's correlation coefficients indicates that the oil concentration and MNP dosage are the most influential variables that affect the oil adsorption capacity. [ABSTRACT FROM AUTHOR]

• Estimation of MNP cluster distribution from recorded AC magnetization spectra. • Model to form matrix equation with MNP distribution & AC magnetization spectra. • Variations in MNP clusters from the model correspond to those measured by DLS. • MNP cluster distributions from the model to determine streptavidin concentration. • Proposed method shows great application potential to the field of biosensing. The hydrodynamic size distribution of magnetic nanoparticle (MNP) clusters is crucial for determining the amounts of biomolecules by analyzing the distributions of the Brownian relaxation time in the corresponding alternating current (AC) magnetization spectra. This study proposes a method for estimating the distribution of MNP clusters from recorded AC magnetization spectra using an experimental-based model. The proposed model is used to form a matrix equation that comprises the distribution and AC magnetization spectra of MNP clusters, and the MNP–biomolecule cluster distribution is obtained by solving an inverse problem. The results show that the variations in the MNP clusters distribution estimated from the model correspond to those measured by dynamic light scattering. The MNP cluster distributions estimated using the experimental model were used to estimate streptavidin concentrations in the range of 0.19–3.38 μM. The estimated values agree accurately with the true values, demonstrating the feasibility of the proposed method for biosensing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 3 O 4 has enzyme-like activities, can be used as an alternative for natural enzymes. • Fe 3 O 4 @mSiO 2 @MMT-SDS nanoparticles were prepared by modifying Fe 3 O 4 @mSiO 2 with MMT and SDS to impart negative charges to the particle surfaces. • Fe 3 O 4 @mSiO 2 @MMT-SDS nanoparticles exhibited excellent catalytic activity for the catalytic oxidation of clenbuterol (CLB) by H 2 O 2 , turning the solution blue in the presence of the 3,3ʹ, 5,5ʹ-tetramethylbenzidine chromogen.. • A novel colorimetric method for clenbuterol detection were demonstrated based on the peroxidase-like activity of Fe 3 O 4 @mSiO 2 @MMT-SDS. This study demonstrates a novel colorimetric method for clenbuterol (CLB) detection based on the peroxidase-like activity of SiO 2 -coated Fe 3 O 4 nanoparticles (Fe 3 O 4 @mSiO 2) modified with montmorillonite (MMT) and sodium dodecyl sulfate (SDS), namely, Fe 3 O 4 @mSiO 2 @MMT-SDS. Fe 3 O 4 @mSiO 2 @MMT-SDS nanoparticles were prepared by modifying Fe 3 O 4 @mSiO 2 with MMT and SDS to impart negative charges to the particle surfaces. The structural properties, steady-state kinetics, catalytic performance, and reaction conditions of the as-prepared nanoparticles were analyzed. Fe 3 O 4 @mSiO 2 @MMT-SDS nanoparticles exhibited excellent dispersion and enzyme-like activity, which improved the affinity with substrate (TMB and H 2 O 2) for the catalytic oxidation of CLB by H 2 O 2 , turning the solution blue in the presence of the 3,3ʹ, 5,5ʹ-tetramethylbenzidine chromogen. Under optimal reaction conditions, a strong linear correlation between the absorbance of solution and CLB concentration (R2 = 0.9983) was observed. Here, the limit of detection, spike recovery, and relative standard deviation were 9.6 × 10-9 mol·L-1, 94.2 %–102.2 %, and 2.2 %–4.4 %, respectively. The proposed method is a simple, fast, cost-efficient, and sensitive assay, which can be used to rapidly and accurately screen CLB in pork and animal feeds. [ABSTRACT FROM AUTHOR]

A standard canonical Markov Chain Monte Carlo method implemented with a single-macrospin movement Metropolis dynamics was conducted to study the hysteretic properties of an ensemble of independent and non-interacting magnetic nanoparticles with uniaxial magneto-crystalline anisotropy randomly distributed. In our model, the acceptance-rate algorithm allows accepting new updates at a constant rate by means of a self-adaptive mechanism of the amplitude of Néel rotation of magnetic moments. The influence of this proposal upon the magnetic properties of our system is explored by analyzing the behavior of the magnetization versus field isotherms for a wide range of acceptance rates. Our results allows reproduction of the occurrence of both blocked and superparamagnetic states for high and low acceptance-rate values respectively, from which a link with the measurement time is inferred. Finally, the interplay between acceptance rate with temperature in hysteresis curves and the time evolution of the saturation processes is also presented and discussed.

Highly selective multifunctional magnetic nanoparticles containing a thermoresponsive polymer shell were developed and used in the sample pretreatment of urine for the assessment of lysozymuria in leukemia patients. Crosslinked poly(N-isopropylacrylamide-co-acrylic acid-co-N-tert-butylacrylamide) was grown onto silica-coated magnetic nanoparticles by reversible addition fragmentation chain transfer (RAFT) polymerization. The lysozyme binding property of the nanoparticles was investigated as a function of time, protein concentration, pH, ionic strength and temperature and their selectivity was assessed against other proteins. High-abundant proteins, like human serum albumin and γ-globulins did not interfere with the binding of lysozyme even at elevated concentrations characteristic of proteinuria. A sample cleanup procedure for urine samples has been developed utilizing the thermocontrollable protein binding ability of the nanoparticles. Method validation was carried out according to current bioanalytical method validation guidelines. The method was highly selective, and the calibration was linear in the 25 to 1000 µg/mL concentration range, relevant in the diagnosis of monocytic and myelomonocytic leukemia. Intra- and inter-day precision values ranged from 2.24 to 8.20% and 1.08 to 5.04%, respectively. Intra-day accuracies were between 89.9 and 117.6%, while inter-day accuracies were in the 88.8 to 111.0% range. The average recovery was 94.1 ± 8.1%. Analysis of unknown urine samples in comparison with a well-established reference method revealed very good correlation between the results, indicating that the new nanoparticle-based method has high potential in the diagnosis of lysozymuria.

The agglomeration of ferromagnetic nanoparticles in a fluid is studied using nanoparticle-level Langevin dynamics simulations. The simulations have interdigitation and bridging between ligand coatings included using a computationally-cheap, phenomenological sticking parameter c. The interactions between ligand coatings are shown in this preliminary study to be important in determining the shapes of agglomerates that form. A critical size for the sticking parameter is estimated analytically and via the simulations and indicates where particle agglomerates transition from well-ordered (c is small) to disordered (c is large) shapes. Results are also presented for the hysteresis loops (magnetization versus applied field) for these particle systems in an oscillating magnetic field appropriate for hyperthermia applications. The results show that the clumping of particles has a significant effect on their macroscopic properties, with important consequences on applications. In particular, the work done by an oscillating field on the system has a nonmonotonic dependence on c.

Due to their unique glycan composition and linkage, protein glycosylation plays significant roles in cellular function and is associated with various diseases. For comprehensive characterization of their extreme structural complexity occurring in >50% of human proteins, time-consuming multi-step enrichment of glycopeptides is required. Here we report zwitterionic n-dodecylphosphocholine-functionalized magnetic nanoparticles (ZIC-cHILIC@MNPs) as a highly efficient affinity nanoprobe for large-scale enrichment of glycopeptides. We demonstrate that ZIC-cHILIC@MNPs possess excellent affinity, with 80–91% specificity for glycopeptide enrichment, especially for sialylated glycopeptide (90%) from biofluid specimens. This strategy provides rapidity (~10 min) and high sensitivity (n = 3) and hepatocellular carcinoma (HCC, n = 3) at the depth of >3000 glycopeptides, especially for the large-scale identification of under-explored sialylated glycopeptides. The glycoproteomics atlas also revealed the differential pattern of sialylated glycopeptides between HBV and HCC groups. The ZIC-cHILIC@MNPs could be a generic tool for advancing the glycoproteome analysis, and contribute to the screening of glycoprotein biomarkers.

Several ternary composites that are based on branched polyethyleneimine (bPEI 25 kDa, polydispersity 2.5, 0.1 or 0.2 ng), citrate-coated ultrasmall superparamagnetic iron oxide nanoparticles (citrate-NPs, 8–10 nm, 0.1, 1.0, or 2.5 µg), and reporter circular plasmid DNA pEGFP-C1 or pRL-CMV (pDNA 0.5 µg) were studied for optimization of the best composite for transfection into glioblastoma U87MG or U138MG cells. The efficiency in terms of citrate-NP and plasmid DNA gene delivery with the ternary composites could be altered by tuning the bPEI/citrate-NP ratios in the polymer composites, which were characterized by Prussian blue staining, in vitro magnetic resonance imaging as well as green fluorescence protein and luciferase expression. Among the composites prepared, 0.2 ng bPEI/0.5 μg pDNA/1.0 µg citrate-NP ternary composite possessed the best cellular uptake efficiency. Composite comprising 0.1 ng bPEI/0.5 μg pDNA/0.1 μg citrate-NP gave the optimal efficiency for the cellular uptake of the two plasmid DNAs to the nucleus. The best working bPEI concentration range should not exceed 0.2 ng/well to achieve a relatively low cytotoxicity.

Monodisperse magnetic γ-Fe2O3 nanoparticles (MNPs) were prepared by a simple, improved, one-pot solvothermal synthesis using SDS and PEG 6000 as double capping reagents. This double protecting layer afforded better MNP uniformity (Z average 257 ± 11.12 nm, PDI = 0.18) and colloidal stability. Materials were characterized by DLS, SEM, TEM, XPS, and XRD. The use of these MNPs in the synthesis of core–shell structures with uniform and tunable silica coatings was demonstrated, as silica coated MNPs are important for use in a range of applications, including magnetic separation and catalysis and as platforms for templated nanogel synthesis.

Zhongyang Liu,1,* Shu Zhu,1,* Liang Liu,2,* Jun Ge,3,4,* Liangliang Huang,1 Zhen Sun,1 Wen Zeng,5 Jinghui Huang,1 Zhuojing Luo1 1Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, 2Department of Orthopedics, No 161 Hospital of PLA, Wuhan, Hubei, 3Department of Orthopedics, No 323 Hospital of PLA, Xi’an, Shaanxi, 4Department of Anatomy, Fourth Military Medical University, Xi’an, Shaanxi, 5Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China *These authors contributed equally to this work Abstract: Peripheral nerve repair is still challenging for surgeons. Autologous nerve transplantation is the acknowledged therapy; however, its application is limited by the scarcity of available donor nerves, donor area morbidity, and neuroma formation. Biomaterials for engineering artificial nerves, particularly materials combined with supportive cells, display remarkable promising prospects. Schwann cells (SCs) are the absorbing seeding cells in peripheral nerve engineering repair; however, the attenuated biologic activity restricts their application. In this study, a magnetic nanocomposite scaffold fabricated from magnetic nanoparticles and a biodegradable chitosan–glycerophosphate polymer was made. Its structure was evaluated and characterized. The combined effects of magnetic scaffold (MG) with an applied magnetic field (MF) on the viability of SCs and peripheral nerve injury repair were investigated. The magnetic nanocomposite scaffold showed tunable magnetization and degradation rate. The MGs synergized with the applied MF to enhance the viability of SCs after transplantation. Furthermore, nerve regeneration and functional recovery were promoted by the synergism of SCs-loaded MGs and MF. Based on the current findings, the combined application of MGs and SCs with applied MF is a promising therapy for the engineering of peripheral nerve regeneration. Keywords: peripheral nerve repair, magnetic nanoparticle, nanocomposite, magnetic field, Schwann cell, functional recovery

Chencai Wang,1 Chao-Hsiung Hsu,1,2 Zhao Li,1 Lian-Pin Hwang,2 Ying-Chih Lin,2 Pi-Tai Chou,2 Yung-Ya Lin1 1Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA; 2Department of Chemistry, National Taiwan University, Taipei, Taiwan Abstract: Magnetic resonance (MR) nano-theranostic hyperthermia uses magnetic nanoparticles to target and accumulate at the lesions and generate heat to kill lesion cells directly through hyperthermia or indirectly through thermal activation and control releasing of drugs. Preclinical and translational applications of MR nano-theranostic hyperthermia are currently limited by a few major theoretical difficulties and experimental challenges in in vivo conditions. For example, conventional models for estimating the heat generated and the optimal magnetic nanoparticle sizes for hyperthermia do not accurately reproduce reported in vivo experimental results. In this work, a revised cluster-based model was proposed to predict the specific loss power (SLP) by explicitly considering magnetic nanoparticle aggregation in in vivo conditions. By comparing with the reported experimental results of magnetite Fe3O4 and cobalt ferrite CoFe2O4 magnetic nanoparticles, it is shown that the revised cluster-based model provides a more accurate prediction of the experimental values than the conventional models that assume magnetic nanoparticles act as single units. It also provides a clear physical picture: the aggregation of magnetic nanoparticles increases the cluster magnetic anisotropy while reducing both the cluster domain magnetization and the average magnetic moment, which, in turn, shift the predicted SLP toward a smaller magnetic nanoparticle diameter with lower peak values. As a result, the heating efficiency and the SLP values are decreased. The improvement in the prediction accuracy in in vivo conditions is particularly pronounced when the magnetic nanoparticle diameter is in the range of ~10–20 nm. This happens to be an important size range for MR cancer nano-theranostics, as it exhibits the highest efficacy against both primary and metastatic tumors in vivo. Our studies show that a relatively 20%–25% smaller magnetic nanoparticle diameter should be chosen to reach the maximal heating efficiency in comparison with the optimal size predicted by previous models. Keywords: nano-theranostics, hyperthermia, magnetic resonance, magnetic nanoparticle, specific loss power

Abstract Background When bacteria colony persist within a biofilm, suitable drugs are not yet available for the eradication of biofilm-producing bacteria. The aim of this study is to study the effect of magnetic nano-particles-induced hyperthermia on destroying biofilm and promoting bactericidal effects of antibiotics in the treatment of osteomyelitis. Methods Sixty 12-weeks-old male Wistar rats were used. A metallic 18G needle was implanted into the bone marrow cavity of distal femur after the injection of Methicillin-sensitive Staphylococcus aureus (MSSA). All animals were divided into 5 different treatment modalities. The microbiological evaluation, scanning electron microscope examination, radiographic examination and then micro-CT evaluation of peri-implant bone resorption were analyzed. Results The pathomorphological characteristics of biofilm formation were completed after 40-days induction of osteomyelitis. The inserted implants can be heated upto 75 °C by magnetic heating without any significant thermal damage on the surrounding tissue. We also demonstrated that systemic administration of vancomycin [VC (i.m.)] could not eradicate the bacteria; but, local administration of vancomycin into the femoral canal and the presence of magnetic nanoparticles hyperthermia did enhance the eradication of bacteria in a biofilm-based colony. In these two groups, the percent bone volume (BV/TV: %) was significantly higher than that of the positive control. Conclusions For the treatment of chronic osteomyelitis, we developed a new modality to improve antibiotic efficacy; the protection effect of biofilms on bacteria could be destroyed by magnetic nanoparticles-induced hyperthermia and therapeutic effect of systemic antibiotics could be enhanced.

Abstract The interfacial instability process is an emerging general method to fabricate nanocrystal-encapsulated micelles (also called micellar nanocrystals) for biological detection, imaging, and therapy. The present work utilized fluorescent semiconductor nanocrystals (quantum dots or QDs) as the model nanocrystals to investigate the interfacial instability-based fabrication process of nanocrystal-encapsulated micelles. Our experimental results suggest intricate and intertwined roles of the emulsion droplet size and the surfactant poly (vinyl alcohol) (PVA) used in the fabrication process of QD-encapsulated poly (styrene-b-ethylene glycol) (PS-PEG) micelles. When no PVA is used, no emulsion droplet and thus no micelle is successfully formed; Emulsion droplets with large sizes (~25 μm) result in two types of QD-encapsulated micelles, one of which is colloidally stable QD-encapsulated PS-PEG micelles while the other of which is colloidally unstable QD-encapsulated PVA micelles; In contrast, emulsion droplets with small sizes (~3 μm or smaller) result in only colloidally stable QD-encapsulated PS-PEG micelles. The results obtained in this work not only help to optimize the quality of nanocrystal-encapsulated micelles prepared by the interfacial instability method for biological applications but also offer helpful new knowledge on the interfacial instability process in particular and self-assembly in general.

Background: Magnetic nanoparticles (NPs) must not only be well-defined in composition, shape and size to exhibit the desired properties (e.g., exchange-bias for thermal stability of the magnetization) but also judiciously functionalized to ensure their stability in air and their compatibility with a polymer matrix, in order to avoid aggregation which may seriously affect their physical properties. Dipolar interactions between NPs too close to each other favour a collective magnetic glass state with lower magnetization and coercivity because of inhomogeneous and frustrated macrospin cluster freezing. Consequently, tailoring chemically (through surface functionalization) and magnetically stable NPs for technological applications is of primary importance.Results: In this work, well-characterized exchange-biased perfectly epitaxial CoxFe3−xO4@CoO core@shell NPs, which were isotropic in shape and of about 10 nm in diameter, were decorated by two different polymers, poly(methyl methacrylate) (PMMA) or polystyrene (PS), using radical-controlled polymerization under various processing conditions. We compared the influence of the synthesis parameters on the structural and microstructural properties of the resulting hybrid systems, with special emphasis on significantly reducing their mutual magnetic attraction. For this, we followed two routes: the first one consists of the direct grafting of bromopropionyl ester groups at the surface of the NPs, which were previously recovered and redispersed in a suitable solvent. The second route deals with an “all in solution” process, based on the decoration of NPs by oleic acid followed by ligand exchange with the desired bromopropionyl ester groups. We then built various assemblies of NPs directly on a substrate or suspended in PMMA.Conclusion: The alternative two-step strategy leads to better dispersed polymer-decorated magnetic particles, and the resulting nanohybrids can be considered as valuable building blocks for flexible, magnetic polymer-based devices.

Background: Multifunctional magnetic nanoparticles (MNP) have been newly developed for tumor-targeted drug carriers. To address challenges including biocompatibility, stability, nontoxicity, and targeting efficiency, here we report the novel drug deliverer poly(ethylene glycol) carboxyl–poly(ɛ-caprolactone) modified MNP (PEG–PCCL-MNP) suitable for magnetic targeting based on our previous studies. Methods: Their in vitro characterization and cytotoxicity assessments, in vivo cytotoxicity assessments, and antitumor efficacy study were elaborately investigated. Results: The size of PEG–PCCL-MNP was 79.6 ± 0.945 nm. PEG–PCCL-MNP showed little in vitro or in vivo cytotoxicity and good biocompatibility, as well as effective tumor-specific cell targeting for drug delivery with the presence of external magnetic field. Discussion: PEG–PCCL-MNP is a potential candidate of biocompatible and tumor-specific targeting drug vehicle for hydrophobic drugs.

Adoptive cell transfer therapy is currently one of the most promising approaches for cancer treatment. This therapy has some limitations, however, such as the dispersion of in vivo-administered cells, causing only a small proportion to reach the tumor. Nanotechnological approaches could offer a solution for this drawback, as they can increase cell retention and accumulation in a region of interest. In particular, strategies employing magnetic nanoparticles (MNPs) to improve targeting of adoptively transferred T or NK cells have been explored in mice. In vivo magnetic retention is reported using the human NK cell line NK-92MI transfected with MNPs. Primary NK cells are nonetheless highly resistant to transfection, and thus we explore in here the possibility of attaching the MNPs to the NK cell surface to overcome this issue, and examine whether this association would affect NK effector functions. We assessed the attachment of MNPs coated with different polymers to the NK cell surface, and found that APS-MNP attached more efficiently to the NK-92MI cell surface. In association with MNPs, these cells preserved their main functions, exhibiting a continued capacity to degranulate, conjugate with and lyse target cells, produce IFN-γ, and respond to chemotactic signals. MNP-loaded NK-92MI cells were also retained in an in vitro capillary flow system by applying an EMF. A similar analysis was carried out in primary NK cells, isolated from mice, and expanded in vitro. These primary murine NK cells also maintained their functionality intact after MNP treatment and were successfully retained in vitro. This work therefore provides further support for using MNPs in combination with EMFs to favor specific retention of functional NK cells in a region of interest, which may prove beneficial to adoptive cell-therapy protocols.

Two models of two- and three-layers of a magnetic nanoparticle are presented applying the Heisenberg theory with the parameter (exchange integral and closest neighbors) values for surface layers, which differ from the bulk layer values. The difference in the numbers of closest neighbors is taken into account. The corresponding distribution and partition functions are constructed. The magnetization of the particles is calculated by the conventional transition to thermodynamics. The results are illustrated by plots, representing magnetization curves and hysteresis loops for the layer contributions. The magnetization curves for both models are compared.

Enzymatic degumming is an effective approach to produce nutritional, safe, and healthy refined oil. However, the high cost and low efficiency of phospholipase limit the application of enzymatic degumming. In this study, an 879 bp outer membrane phospholipase A (A1) (OM-PLA1) gene encoding 292 amino acid residues was isolated from the genome of Serratia marcescens. The recombinant OM-PLA1 profile of appropriately 33 KDa was expressed by the engineered Pichia pastoris GS115. The OM-PLA1 activity was 21.2 U/mL with the induction of 1 mM methanol for 72 h. The expression efficiencies of OM-PLA1 were 0.29 U/mL/h and 1.06 U/mL/OD600. A complex of magnetic graphene oxide (MGO) and OM-PLA1 (MGO-OM-PLA1) was prepared by immobilizing OM-PLA1 with graphene oxide-based Fe3O4 nanoparticles by cross-linking with glutaraldehyde. The content of phosphorus decreased to 5.1 mg/kg rapeseed oil from 55.6 mg/kg rapeseed oil with 0.02% MGO-OM-PLA1 (w/w) at 50°C for 4 h. MGO-OM-PLA1 retained 51.7% of the initial activity after 13 times of continuous recycling for the enzymatic degumming of rapeseed oil. This study provided an effective approach for the enzymatic degumming of crude vegetable oil by developing a novel phospholipase and improving the degumming technology.

Macrophages are known to depict two major phenotypes: classically activated macrophages (M1), associated with high production of pro-inflammatory cytokines, and alternatively activated macrophages (M2), which present an anti-inflammatory function. A precise control over M1-M2 polarization is a promising strategy in therapeutics to modulate both tissue regeneration and tumor progression processes. However, this is not a simple task as macrophages behave differently depending on the microenvironment. In agreement with this, non-consistent data have been reported regarding macrophages response to magnetic iron oxide nanoparticles (MNPs). To investigate the impact of both tissue microenvironment and MNPs properties on the obtained macrophage responses, single-core (SC) and multi-core (MC) citrate coated MNPs, are synthesized and, afterwards, loaded with a macrophage polarization trigger, IL-4. The developed MNPs are then tested in macrophages subjected to different stimuli. We demonstrate that macrophages treated with low concentrations of MNPs behave differently depending on the polarization stage independently of the concentration of iron. Moreover, we find out that MNPs size and morphology determines the effect of the IL-4 loaded MNPs on M1 macrophages, since IL-4 loaded SC MNPs favor the polarization of M1 macrophages towards M2 phenotype, while IL-4 loaded MC MNPs further stimulate the secretion of pro-inflammatory cytokines., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Recently, the presence of different nanoparticles (NPs) has developed targeting drug delivery in treatment of cancer cell. Targeted drug delivery systems using NPs have shown great promise in improving the efficacy of intracellular uptake as well as local concentration of therapeutics with minimizing side effects. The current study planned to synthesized resveratrol-loaded magnetic niosomes nanoparticles (RSV-MNIONPs) and evaluate their cytotoxicity activity in pancreatic cancer cells. For this aim, magnetic nanoparticles (MNPs) were synthesized and loaded into niosomes (NIOs) by the thin film hydration technique and then characterized via DLS, FT-IR, TEM, SEM and VSM techniques. Moreover, the cytotoxic activity of the RSV-MNIONPs on the Capan-1 cells line was assessed by the MTT test. The distribution number of RSV-MNIONPs was gained about 80 nm and 95 nm with surface charge of - 14.0 mV by SEM and TEM analysis, respectively. RSV loading efficacy in NIOs was about 85%, and the drug releases pattern displayed a sustained discharge with a maximum amount about 35% and 40%, within 4 h in pH = 7.4 and pH = 5.8, respectively. The cytotoxicity of the RSV-MNIONPs in the presence of an external magnetic field is higher than that of the RSV, indicating enhanced cellular uptake in their encapsulated states. Furthermore, RSV loaded MNNPs were found to induce more cell cycle arrest at the G0/G1 checkpoint than free RSV. Compared with RSV-treated cells, the mRNA expression levels of BAX, Bcl2, FAS, P 53, Cyclin D and hTERT, were significantly changed in cells treated with RSV loaded MNNPs. The niosomes NPs approaches have been widely used to attain higher solubility, improved bioavailability, enhanced stability, and control delivery of RSV. Our formulation displayed antitumor activity and can be considered an appropriate carrier with a great potential for future usage in cancer therapy., (© 2024. The Author(s).)

Advancements in biofabrication have led to major strides toward creating authentic organ models; however, replicating intricate organ structures without scaffolds remains challenging. In this study, we introduce a method utilizing surface-modifiable magnetic nanofibers to achieve precise control over spheroid functions and geometrical features, allowing the creation of multiple functional domains within a single microtissue. We generated magnetized nanofibers by electrospinning magnetic nanoparticles dispersed in poly-L-lactic acid solution. These fibers were then coated with polydopamine (PD) to enhance their biological functions, particularly reactive oxygen species (ROS) scavenging. These PD-coated magnetic fibers (PMFs) had magnetic-responsive properties when incorporated into human dermal fibroblast spheroids (0.019 ± 0.001 emu g -1 ). Furthermore, PMFs within the spheroids effectively regulated ROS levels by upregulating the expression of key anti-oxidative genes such as superoxide dismutase-1 (2.2 ± 0.1) and glutathione peroxidase-1 (2.6 ± 0.1). By exploiting the magnetic responsiveness of spheroids, we were able to assemble them into various structures such as linear, triangular, and square structures using remotely applied magnetic forces. Within the assembled three-dimensional constructs, the cells in spheroids incorporating PMFs demonstrated resistance to ROS regulatory activity in the presence of hydrogen peroxide, while spheroids composed of bare fibers exhibited high ROS levels. Furthermore, we assembled spheroids containing fibroblasts and endothelial cells into complex tissue structures resembling vessels under magnetic manipulation. This innovative method holds tremendous promise for organ modeling and regenerative medicine due to the unprecedented control it allows in developing microtissues that closely emulate real organs., (© 2024 IOP Publishing Ltd.)

Cancer is still the leading cause of death in the world despite the developing research and treatment opportunities. Failure of these treatments is generally associated with cancer stem cells (CSCs), which cause metastasis and are defined by their resistance to radio- and chemotherapy. Although known stem cell isolation methods are not sufficient for CSC isolation, they also bring a burden in terms of cost. The aim of this study is to develop a high-efficiency, low-cost, specific method for cancer stem cell isolation with magnetic functional nanoparticles. This study, unlike the stem cell isolation techniques (MACS, FACS) used today, was aimed to isolate cancer stem cells (separation of CD133 + cells) with nanoparticles with specific affinity and modification properties. For this purpose, affinity-based magnetic nanoparticles were synthesized and characterized by providing surface activity and chemical reactivity, as well as making surface modifications necessary for both lectin affinity and metal affinity interactions. In the other part of the study, synthesized and characterized functional polymeric magnetic nanoparticles were used for the isolation of CSC from the human osteosarcoma cancer cell line (SAOS-2) with a cancer stem cell subpopulation bearing the CD133 surface marker. The success and efficiency of separation after stem cell isolation were evaluated via the MACS and FACS methods. As a result, when the His-graft-mg-p(HEMA) nanoparticle was used at a concentration of 0.1 µg/mL for 10 6 and 10 8 cells, superior separation efficiency to commercial microbeads was obtained.

Mycotoxin contamination of food crops is a global challenge due to their unpredictable occurrence and severe adverse health effects on humans. Therefore, it is of great importance to develop effective tools to prevent the accumulation of mycotoxins through the food chain. The use of magnetic nanoparticle (MNP)-assisted biosensors for detecting mycotoxin in complex foodstuffs has garnered great interest due to the significantly enhanced sensitivity and accuracy. Within such a context, this review includes the fundamentals and recent advances (2020-2023) in the area of mycotoxin monitoring in food matrices using MNP-based aptasensors and immunosensors. In this review, we start by providing a comprehensive introduction to the design of immunosensors (natural antibody or nanobody, random or site-oriented immobilization) and aptasensors (techniques for aptamer selection, characterization, and truncation). Meanwhile, special attention is paid to the multifunctionalities of MNPs (recoverable adsorbent, versatile carrier, and signal indicator) in preparing mycotoxin-specific biosensors. Further, the contribution of MNPs to the multiplexing determination of various mycotoxins is summarized. Finally, challenges and future perspectives for the practical applications of MNP-assisted biosensors are also discussed. The progress and updates of MNP-based biosensors shown in this review are expected to offer readers valuable insights about the design of MNP-based tools for the effective detection of mycotoxins in practical applications., (© 2023 Institute of Food Technologists®.)

Hydrocortisone, a commonly used anti-inflammatory drug, has limited aqueous solubility and several side effects. To address this challenge, as a proof-of-concept, this article demonstrates the development of a controlled-release drug delivery system (DDS) for hydrocortisone using chitosan-grafted poly( N -vinylcaprolactam) (CS- g -PNVCL)-coated core-shell Fe 3 O 4 @SiO 2 nanoformulations (NFs). Reported magnetic nanoparticles (NPs) were synthesized and modified with silica, PNVCL, and CS precursors to enhance the biocompatibility of DDS and drug-loading efficiency. The release rate of hydrocortisone from Fe 3 O 4 @SiO 2 @CS- g -PNVCL NFs was observed to be higher at lower pH values, and the smart polymer coating demonstrated temperature responsiveness, facilitating drug release at higher temperatures. Fe 3 O 4 @SiO 2 @CS- g -PNVCL NFs exhibited a cell viability of around 97.2 to 87.3% (5-100 μg/mL) after 24-48 h, while the hydrocortisone-NFs had a cell viability of around 93.2 to 82.3%. Our findings suggest that CS- g -PNVCL-coated Fe 3 O 4 @SiO 2 NPs effectively enhance the solubility, loading capacity, and targeted delivery of poorly soluble drugs, thereby improving their therapeutic efficacy and bioavailability.

This research work reports the magnetic adsorption of fluoride from drinking water through silica-coated Fe3O4 nanoparticles. Chemical precipitation and wet impregnation methods were employed to synthesize the magnetic nanomaterials. Moreover, the synthesized nanomaterials were characterized for physicochemical properties through scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray powder diffraction. Screening studies were conducted to select the best iron oxide loading (0.0–1.5 wt%) and calcination temperature (300–500 °C). The best selected nanomaterial (0.5Fe-Si-500) showed a homogenous FeO distribution with a 23.79 nm crystallite size. Moreover, the optimized reaction parameters were: 10 min of contact time, 0.03 g L−1 adsorbent dose, and 10 mg L−1 fluoride (F−) concentration. Adsorption data were fitted to the Langmuir and Freundlich isotherm models. The Qm and KF (the maximum adsorption capacities) values were 5.5991 mg g−1 and 1.869 L g−1 respectively. Furthermore, accelerated adsorption with shorter contact times and high adsorption capacity at working pH was among the outcomes of this research work.

Microscale and nanoscale robots, frequently referred to as future cargo systems for targeted drug delivery, can effectively convert magnetic energy into locomotion. However, navigating and imaging them within a complex colloidal vascular system at a clinical scale is exigent. Hence, a more precise and enhanced hybrid control navigation and imaging system is necessary. Magnetic particle imaging (MPI) has been successfully applied to visualize the ensemble of superparamagnetic nanoparticles (MNPs) with high temporal sensitivity. MPI uses the concept of field-free point (FFP) mechanism in the principal magnetic field. The gradient magnetic field (|∇B|) of MPI scanners can generate sufficient magnetic force in MNPs; hence, it has been recently used to navigate nanosized particles and micron-sized swimmers. In this article, we present a simulation analysis of the optimized navigation of an ensemble of microsized polymer MNP-based drug carriers in blood vessels. Initially, an ideal two-dimensional FFP case is employed for the basic optimization of the FFP position to achieve efficient navigation. Thereafter, a nine-coil electromagnetic actuation simulation system is developed to generate and manipulate the FFP position and |∇B|. Under certain vessel and fluid conditions, the particle trajectories of different ferromagnetic polymer ratios and |∇B| were compared to optimize the FFP position.

A novel assembly method was used to prepare the sulfhydryl functionalized magnetic SBA-15 (SH-M-SBA-15). The physicochemical properties of SH-M-SBA-15 were characterized by TEM, XRD, EDS, FT-IR, BET, and VSM. Batch adsorption experiments were conducted to investigate the influence of initial uranium concentration, dosage of adsorbent, pH values, contact time, and temperature on the adsorption efficiency and behaviors. The adsorption types were analyzed from the aspects of kinetic, isotherms, and thermodynamic. The results show that the specific surface area of SH-M-SBA-15 is 316.67 m2/g, which is smaller than that of SBA-15 (692.18 m2/g). However, compared with SBA-15, SH-M-SBA-15 has more surface sulfhydryl functional groups. The addition of this group can improve the adsorption of uranyl ions by SH-M-SBA-15. The optimal adsorption conditions were adsorption dosage 40 mg/L, pH 6, temperature 35 °C, contact time 180 min, and initial uranium concentration 35 mg/L. Under this condition, the maximum adsorption amount of uranyl ion by SH-M-SBA-15 can reach 804.79 mg/g, which is much higher than the highest adsorption capacity of uranyl ion by SBA-15 (146.23 mg/g). The adsorption process was better depicted by the Langmuir isotherm model. The process was consistent with the quasi-second-order model. ΔG was negative and ΔH was positive, indicating spontaneous and endothermic adsorption. [ABSTRACT FROM AUTHOR]

Microwave heating is one of the prominent treatment procedure that elevates body temperature using microwave energy to damage tumor cells. However, healthy tissues can also absorb microwave energy causing undesired damage. This research study focuses on optimizing the surrounding healthy tissue damage by diffusing magnetic nanoparticles (NPs) in the tumor region. A rectangular liver tissue is modeled using Finite Element Methods (FEM) and then a half-elliptical shaped tumor is incorporated in the model. A coaxial antenna covered with a polytetrafluoroethylene catheter is inserted at the edge of the liver tissue. Then the magnetic NPs are diffused within the tumor region. The performance of microwave heating with and without nanoparticle diffusion is compared using the performance parameters: power dissipation density, temperature distribution, and resultant tissue necrosis. Simulation results show that the heating procedure coupled with ferromagnetic nanoparticle diffusion has approximately 14% less damage to the healthy tissue. The study also shows that 433/915 MHz frequency value provides 3% less damage to the healthy tissue than 2.45 GHz. Analyzing the performance of different nanoparticle we found that the ferromagnetic nanoparticle provides 15% and 5% less damage to the healthy tissue than gold and manganese iron oxide NPs respectively. The obtained result was also verified for kidney, breast, and lung tumor ablations to confirm the findings. [ABSTRACT FROM AUTHOR]

Demulsification efficiency of diluted waste cutting fluid by magnetic demulsifiers was investigated and the soild concentration (C S) effect was observed. A C S -effect was observed in magnetic demulsification systems. This study evaluated the demulsifying capability of magnetic nanoparticles for industrial wastewater treatment and the solid effect during demulsification. In order to evaluate the demulsification capability of magnetic nanoparticles, an oleic acid-coated magnetite (Fe 3 O 4 @OA) was used as a demulsifier for demulsification of diluted waste cutting fluid (DWCF) rom machining and manufacturing. The effects of the magnetic nanoparticles dosage (C S), the pH, cetyltrimethyl ammonium bromide (CTAB) and electrolytes (NL and CL) in DWCF on the demulsification efficiency (E D) were investigated. It was observed that the E D enhanced when electrolytes NL and CL were added into DWCF and decreased with pH increasing. Meanwhile, in the magnetic demulsification systems, a significant solid concentration effect (or C S -effect) was observed, that is the equilibrium adsorption amount (Γ e) declined as C S increased. These C S -effect data can be explained using the surface component activity (SCA) model. The C S -effect strength (or γ value) declined in turn with the NL, CL and CTAB added and declined with pH increasing. The paper further discusses the rationale for the observed results. This paper provides a new perspective on magnetic demulsification and demonstrates that SCA model can be applied to describe the C S -effect phenomenon exactly in magnetic demulsification systems. [ABSTRACT FROM AUTHOR]

• The combine of ultrasound and rotational magnetic field enhance thrombolysis rate. • Clot lysis was enhanced with magnetic microbubble in a rotational magnetic field. • Clot lysis rate increase as the rotational magnetic field flux density increase. • Clot lysis rate increase as the rotational magnetic field frequency increase. Thrombosis is an extremely critical clinical condition where a clot forms inside a blood vessel which blocks the blood flow through the cardiovascular system. Previous sonothrombolysis methods using ultrasound and microbubbles (MBs) often have a relatively low lysis rate due to the low microbubbles concentration at clot region caused by blood flow in the vessel. To solve this problem, the magnetic microbubbles (MMBs) that can be retained by an outer magnetic field against blood flow are used in this study. Here we report the development of a new method using the rotational magnetic field to trap and vibrate magnetic microbubbles at target clot region and then using an intravascular forward-looking ultrasound transducer to activate them acoustically. In this study, we investigated the influence of different blood flow conditions, vessel occlusion conditions (partial and fully occluded), clot ages (fresh, retracted), ultrasound parameters (input voltage, duty cycle) and rotational magnetic field parameters (amplitude, frequency) on the thrombolysis rate. The results showed that the additional use of magnetic microbubbles significantly enhances in vitro lysis of blood clot. [ABSTRACT FROM AUTHOR]

In this study, ferrofluid of magnetic nanoparticles, oleic acid (OA), combined with hydrophobic deep eutectic solvent (Fe 3 O 4 [iron oxide]-OA-DES) was prepared and coupled with vortex-assisted liquid phase microextraction, to pre-concentrate and determine mefenamic acid (MFA) in urine samples, following high performance liquid chromatography (HPLC). With regard to Fe 3 O 4 nanoparticles, all sorbents were identified by SEM, TEM, and XRD. In addition, the influence of different parameters such as pH, ferrofluid volume, ionic strong (NaCl concentration %), and vortex time was investigated and optimized by response surface methodology (RSM) and central composite design (CCD). Maximum MFA extraction predicted by RSM (97.66) was achieved at pH 4.0, 60 μL of ferrofluid, 3%w/v NaCl, and 7 min vortex time with desirability of 1.0. Under the optimized conditions, the limits of detection (LOD) and the limit of quantification (LOQ) were 1.351 ng mL−1 and 4.575 ng mL−1, respectively. The intra-day and inter-day precision (RSD [relative standard deviation]%) in the concentrations of 50, 300, and 700 ng mL−1 of MFA were less than 3.6% and 4.2%, respectively. The method developed in our study could successfully determine MFA in urine samples. The MFA microextraction in urine samples were between 80.25 and 97.44% with RSD% less than 4.60%. Inclusion of ferrofluid in a miniaturized method for sample preparation is proportional to the achievement of high microextraction percentage using green analytical method. Image 1 • Application of hydrophobic deep eutectic solvent as the carrier for ferrofluid. • Pre-concentration and determination of Mefenamic acid in urine samples. • Application of vortex-assisted liquid-phase microextraction. [ABSTRACT FROM AUTHOR]

Modern chemotherapeutic anticancer treatments have come a long way in the fight against breast cancer, thus bringing science closer to a cure. However, the nature of these drugs is to attack both cancerous and non-cancerous cells at the same time. In our studies, we synthesized Magnetic Cyclodextrin-polyurethane based nano-composite (Fe3O4-ECA-PU-CD) which is a drug delivery system using a biocompatible magnetic polymer that directs chemotherapeutic drugs to cancerous regions in the body with an external magnet. This nano-composite was able to facilitate the loading and simultaneous release of the hydrophilic antitumor drug Doxorubicin (DOX) along with the hydrophobic antitumor drug docetaxel. The composite was made using a simple co-precipitation method with magnetic nano-particles (MNPs) followed by a silica coating process and an in situ polymerization process. Verification of synthesis for the drug carrier was carried out using techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and a vibrating sample magnetometer (VSM) to measure magnetic properties. Drug loading and release efficiencies were monitored using an HPLC-UV detector. Finally, an MTT assay was performed in order to evaluate the biocompatibility and toxicity of the synthetic nano-composite on MCF7 cell lines. Our findings present a new biocompatible drug delivery system with a high capacity for loading and directing two different chemotherapeutic drugs simultaneously to cancer sites with little to no toxicity to the surrounding non-cancerous cells. These studies present a viable tool for cancer treatment and research where the cancer is efficiently removed while the patient remains healthy. [ABSTRACT FROM AUTHOR]

To develop a remote control system of transgene expression through localized cellular heating of magnetic nanoparticles, a heat-inducible transgene expression system was introduced into mammalian cells. Cells were labeled with magnetic nanoparticles and exposed to an alternating magnetic field. The magnetically labeled cells expressed the transgene in a monolayer and multilayered cell sheets in which cells were heated around the magnetic nanoparticles without an apparent temperature increase in the culture medium. Magnetic cells were also generated by genetically engineering with a ferritin gene, and transgene expression could be induced by exposure to an alternating magnetic field. This approach may be applicable to the development of novel gene therapies in cell-based medicine. [ABSTRACT FROM AUTHOR]

Adoptive cell transfer therapy is currently one of the most promising approaches for cancer treatment. This therapy has some limitations, however, such as the dispersion of in vivo -administered cells, causing only a small proportion to reach the tumor. Nanotechnological approaches could offer a solution for this drawback, as they can increase cell retention and accumulation in a region of interest. In particular, strategies employing magnetic nanoparticles (MNPs) to improve targeting of adoptively transferred T or NK cells have been explored in mice. In vivo magnetic retention is reported using the human NK cell line NK-92MI transfected with MNPs. Primary NK cells are nonetheless highly resistant to transfection, and thus we explore in here the possibility of attaching the MNPs to the NK cell surface to overcome this issue, and examine whether this association would affect NK effector functions. We assessed the attachment of MNPs coated with different polymers to the NK cell surface, and found that APS-MNP attached more efficiently to the NK-92MI cell surface. In association with MNPs, these cells preserved their main functions, exhibiting a continued capacity to degranulate, conjugate with and lyse target cells, produce IFN-γ, and respond to chemotactic signals. MNP-loaded NK-92MI cells were also retained in an in vitro capillary flow system by applying an EMF. A similar analysis was carried out in primary NK cells, isolated from mice, and expanded in vitro. These primary murine NK cells also maintained their functionality intact after MNP treatment and were successfully retained in vitro. This work therefore provides further support for using MNPs in combination with EMFs to favor specific retention of functional NK cells in a region of interest, which may prove beneficial to adoptive cell-therapy protocols. [ABSTRACT FROM AUTHOR]

Nanoparticle-based thrombolysis is a potential new treatment for stroke. The aim of this study was to investigate the efficacy of targeted thrombolysis using recombinant tissue plasminogen activator (rtPA). The rtPA was covalently bound to magnetic nanoparticles (MNP) and maintained at the target site using an external magnet. Polyacrylic acid (PAA)-coated MNP were synthesized and rtPA was then bound to the resultant PAA-MNP via carbodiimide-mediated amide bonds. For the in vitro tests, blood clots were formed in plastic centrifuge tubes with anti-coagulated plasma, thrombin and calcium chloride. For the in vivo tests, mice with ferric chloride-induced distal middle cerebral artery occlusion were treated with phosphate-buffered saline (PBS), MNP, rtPA, or MNP-rtPA (n = 6 mice per group). The binding efficacy was 80.7 ± 1.5 μg rtPA bound to 1 mg PAA-MNP. In the in vitro tests, the mean lysis percentage dramatically increased from 1.28% in the MNP group without rotation to 77.40% in the rtPA + MNP group with rotating magnetic field. The lysis efficiency of MNP-rtPA was 27.3 ± 1.3%, and it increased to 42.8 ± 2.8% with magnetic field rotation. The mean sizes of the infarct areas of the PBS, MNP, rtPA, and MNP-rtPA mouse groups were 20.09 ± 6.07, 18.28 ± 2.69, 8.65 ± 3.63 and 4.40 ± 2.46 mm3, respectively. Thus, targeted MNP-rtPA accelerated thrombolysis and reduced the infarct area in a mouse model of cerebral embolism. This approach may serve as a feasible and effective treatment for embolic cerebral ischemia. • Polyacrylic acid-coated nanoparticles can bind with tissue plasminogen activator. • MNP-rtPA accelerate thrombolysis in vitro. • MNP-rtPA significantly reduce infarct volume in mice MCA model. [ABSTRACT FROM AUTHOR]

In this work, a novel quartz crystal microbalance (QCM) aptasensor is designed for the diagnosis of Brucella melitensis bacteria, which affects the Mediterranean fever (brucellosis) from the zoonotic diseases that are very common in the Middle East Countries. The method is based on the selection of B. melitensis bacterium from solutions using B. melitensis specific binding aptamer (Apt) attached magnetic nanoparticles. The surface of the magnetic nanoparticles (i.e.,Fe 3 O 4) was modified by 3-aminopropyltriethoxysilane (APTES) and then grafted with a hydrophilic macromonomer poly(ethyleneglycol)-methacrylate (PEG-MA) as a first block polymer and glycidylmethacrylate (GMA) as a second block functional polymer via atom transfer radical polymerization (ATRP) method [Fe 3 O 4 @SiO 2 @p(PEG-MA-GMA)], then, the specific binding aptamer was immobilized. The aptamer immobilized magnetic nanoparticles were used for the pre-concentration of the target bacterium, and the same aptamer sequence was also immobilized on the QCM chip and used for the quantitative detection of B. melitensis using QCM aptasensor. The detection limits of the QCM aptasensor were in the range 1.02–1.07 CFU mL−1, with recoveries up to 79%. The synthesized [Fe 3 O 4 @SiO 2 @p(PEGMA-GMA)] nanoparticles showed a good permanence and high isolation recoveries for the pull down of the target bacterium from food samples, after recycling eight times. The method was successfully applied to target bacterium determinations in milk and milk product samples. fx1 • A QCM-aptasensor was designed for the determination of B. melitensis from food samples. • The aptamers on magnetic particles and QCM sensor chips have high specificity to target bacteria. • B. melitensis detection limit of the QCM-aptasensor was found to 100 CFU mL−1. • The pre-concentration with same aptamer offered sensitive detection of target bacteria. • The binding of bacterial cells to QCM-aptasensor was well described by Langmuir model. [ABSTRACT FROM AUTHOR]