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Iron(iii) oxide nanoparticles doped with magnesium exposed to an alternating magnetic field induced cytotoxic effects on lung cancer cells (A549).

Recent advances in nanomedicine have paved the way for developing targeted drug delivery systems. Nanoscale exosomes are present in almost every body fluid and represent a novel mechanism of intercellular communication. Because of their membrane origin, they easily fuse with cells, acting as a natural delivery system and maintaining the bioactivity and immunotolerance of cells. To develop a reconstitutable exosome-based drug candidate for clinical applications, quality assurance by preserving its physical and biological properties during storage is necessary. Therefore, this study aimed to determine the best storage conditions for exosomes derived from lung cancer cells (A549). This study established that the phosphate-buffered saline buffer enriched with 25 mM trehalose is an optimal cryoprotectant for A549-derived exosomes stored at -80°C. Under these conditions, the concentration, size distribution, zeta potential, and total cargo protein levels of the preserved exosomes remained constant.

In every pandemic, it is critical to test as many people as possible and keep track of the number of new cases of infection. Therefore, there is a need for novel, fast and unambiguous testing methods. In this study, we designed a sandwich-type voltammetric immunosensor based on unlabeled- and labeled with a redox probe antibodies against virus spike protein for fast and ultrasensitive detection of SARS-CoV-2. The process of the preparation of the sensor layer included chemisorption of cysteamine layer and covalent anchoring of antibody specific for the S1 subunit of the S protein. The source of the voltametric signal was the antibody labeled with the redox probe, which was introduced onto biosensor surface only after the recognition of the virus. This easy-to-handle immunosensor was characterized by a wide analytical range (2.0·10

In this study, we developed novel, simple gravimetric and voltammetric sensors for the ultrasensitive detection of active matrix metalloproteinase (MMP)-2 in plasma. The developed sensors are cost-effective, require a very less amount of reagents, and are time-saving. They detect MMP-2 based on antigen-antibody recognition and its ability to cleave glycine-leucine peptide bond. The three-dimensional bioplatform of the sensors consisted of a cationic polyethyleneimine (PEI) polymer that facilitated robust immobilization of the dipeptide labeled with anthraquinone (AQ), or antibody molecules in appropriate density, which was crucial for biosensing. Detection was performed using quartz crystal microbalance with dissipation and voltammetry. The results showed that the developed sensors were characterized by high stability, wide analytical range (2.0 pg mL

Studies over the last decade have shown that matrix metalloproteinases (MMPs) play a key role in the growth and metastasis of cancer. This zinc-dependent family of endopeptidases is crucial for the degradation of extracellular matrix (ECM), as well as serves as important ECM transducers which have been recognized as early biomarkers for both cancer diagnosis and treatment. In this study, we designed a new type of voltammetric biosensor, composed of a glycine-methionine dipeptide conjugated covalently to ferrocene (Gly-Met-Fc), for fast and ultrasensitive detection of the active form of MMP-9 in plasma samples. The detection was based on specific enzymatic cleavage of the Gly-Met peptide bond, which was monitored by voltammetry and gravimetry measurements. The ferrocene units act as voltammetric visualizers for the detection process. The cysteamine layer directly anchored to the gold surface ensured that the packing density of Gly-Met-Fc in the receptor layer was appropriate for the sensitive detection of MMP-9 in its active form. The developed biosensor was characterized by the widest analytical range (2.0·10−6 - 5.0 μg⋅mL−1) and low detection limit (0.04 pg⋅mL−1). Another valuable feature of the proposed biosensor is that it can be applied directly to the plasma samples without any additional preparation step and thus speeds up the analysis.

Non-alcoholic fatty liver disease (NAFLD) is considered to be the leading cause of liver pathologies worldwide. Accurate diagnosis and staging of NAFLD is of utmost prognostic importance. Herein, we propose the application of multiparametric MRI in whole-body fat imaging that may serve in obesity and NAFLD diagnosis as we established based on an experimental preclinical model of high-calorie diet-induced NAFLD rats.Sprague Dawley male rats randomly divided into control and high-fat diet (HFD) groups to develop NAFLD were used in the experiments. After 12 weeks of the feeding the animals were subjected to MRI modalities based on the Dixon mode and DWI following T2-weighted imaging. Moreover, serum TAG, liver histopathological examination and liver fatty acids analysis (GC-MS) were also performed. The qualitative analysis of DWI images revelated the decrease of signals in the liver of rats subjected to HFD. The statistical analysis of signals from the water- and fat-separated voxels on Dixon images also showed the increase of the fat tissue along with the decrease of water molecules in the liver parenchyma of obese animals. The quantitative analysis of Dixon images allowed to estimate the statistically significant changes of whole-body fat profiles in both normal and obese rats. Histological analysis of the liver tissues, serum TAG and fatty acids profile in the livers confirmed the changes in the fat profile as demonstrated in MRI studies.The MRI-based modalities such as DWI and Dixon method provide both qualitative and quantitative data on the whole-body fat distribution and adipose tissues in the liver parenchyma of obese rats. The results show that MRI is a promising and reliable method and has potential to be used as a non-invasive translational biomarker in NAFLD.

Nearly half of patients with advanced and metastatic melanomas harbor a BRAF mutation. Vemurafenib (VEM), a BRAF inhibitor, is used to treat such patients, however, responses to VEM are very short-lived due to intrinsic, adaptive and/or acquired resistance. In this context, we present the action of the B-Raf serine-threonine protein kinase inhibitor (vemurafenib) on the glycans structure and metallomics profiles in melanoma cells without (MeWo) and with (G-361) BRAF mutations. The studies were performed using &alpha, 1-acid glycoprotein (AGP), a well-known acute-phase protein, and concanavalin A (Con A), which served as the model receptor. The detection of changes in the structure of glycans can be successfully carried out based on the frequency shifts and the charge transfer resistance after interaction of AGP with Con A in different VEM treatments using QCM-D and EIS measurements. These changes were also proved based on the cell ultrastructure examined by TEM and SEM. The LA-ICP-MS studies provided details on the metallomics profile in melanoma cells treated with and without VEM. The studies evidence that vemurafenib modifies the glycans structures and metallomics profile in melanoma cells harboring BRAF mutation that can be further implied in the resistance phenomenon. Therefore, our data opens a new avenue for further studies in the short-term addressing novel targets that hopefully can be used to improve the therapeutic regiment in advanced melanoma patients. The innovating potential of this study is fully credible and has a real impact on the global patient society suffering from advanced and metastatic melanomas.

This work presents a new look at the application of cyclodextrins (CD) as a drug nanocarrier. Two different cyclodextrins (&alpha, CD, &beta, CD) were covalently conjugated to branched polyethylenimine (PEI), which was additionally functionalized with folic acid (PEI-&beta, CD-&alpha, CD-FA). Here, we demonstrated that the combination of &alpha, CD and &beta, CD enabled to load and control release of two anticancer drugs: doxorubicin (DOX) and beta-lapachone (beta-LP) (DOX in &beta, CD and beta-LP into &alpha, CD) via host-guest inclusion. The PEI-&beta, CD(DOX)-&alpha, CD-FA nanoconjugate was used to transport anticancer drugs into A549 lung cancer cells for estimation the cytotoxic and antitumor effect of this nanoconjugate. The presence of FA molecules should facilitate the penetration of studied nanoconjugate into the cell. Whereas, the non-cellular experiments proved that the drugs are released from the carrier mainly in the pH 4.0. The release mechanism is found to be anomalous in all studied cases.

Background Lung cancer is one of the most frequently diagnosed cancer all over the world and a leading cancer-related mortality. The therapy of lung cancer includes surgery, chemotherapy and radiatherapy and mailny depends on the type and stage of lung cancer characterized based on WHO guidelines. Althought the conventional chemotherapy is the main treatment option for small cell lung cancer (SCLC) and a common treatment for non-SCLC it is characterized with lack of specificity resulting to severe toxicities of normal cells and harmful side effects. Therefore, targeted drug delivery (TDD) systems have been used to reduce the systemic toxicity of some conventional chemotherapies in lung cancer. Quantum dots (QDs) are fascinating nanoscale crystals that can serve as nanocarriers in TDD due to their unique physicochemical properties. Therefore, in this paper, the as-desiged QDs, Ag-In-Zn-S-based nanoconjugates for selective doxorubicin (DOX) targeting to lung cancer cells were developed. The QD nanocrystals were modified with 11-mercaptoundecanoic acid (MUA), L-cysteine (Cys) and lipoic acid (LA) used as drug carriers for targeted delivery of DOX to A549 cells through conjugated folic acid (FA) a self-navigation molecule that docks to the folate receptors on cancer cells. The comprechensive physicochemical, cytotoxicity and genotoxicity studies were performed to characterise the novel QD-based nanocaries and their anticancer cargos. Results The results from FTIR, DLS and fluorescence quenching evidenced the successful attachment of FA to the QDs nanocrystals and DOX to the QDs-FA nanocarriers. UV-vis analysis determined the amount of FA and DOX covalently anchored to the QDs nanocrystal surface. Biological screeining revealed that QDs-FA-DOX nanoconjugates showed higher cytotoxicity in comparison to other forms of the synthesized QD samples, suggesting the cytotoxic effect of liberated DOX from the QD constructs. QD-MUA-FA-DOX occurred to be the most cytotoxic against A549 cells among nanoconjugates. In vitro scratch assay also revealed significant inhibition of A549 migration only due to treatment with QD-MUA-FA-DOX. Studies evidenced that all the nanoconjugates at IC 50 induced significantly more DNA breaks than that observed in non-treated cells. All in all, significant and the greatest cytotoxicity, genotoxicity together with inhibition of migratory potential of A549 cells was observed for QD-MUA-FA-DOX. Conclusion The studies show the therapeutic efficacy of DOX-loaded QD-based cargos suggesting their promising role as novel drug delivery systems navigating to folate receptors in lung cancer cells.

The development of carbon-encapsulated iron nanoparticles (CEINS) is of considerable interest in many areas of cancer nanotechnology, ranging from basic tumor biology to early detection and treatment of cancer. To meet these challenges, the present study was undertaken to determine the magnetic and relaxometric performance of CEINS used as a new contrast agent for magnetic resonance imaging (MRI) in preclinical phantom models. CEIN samples were synthesized using a carbon arc discharge route, and the as-synthesized nanoparticles were purified and functionalized with surface acidic groups. The presence of various Fe-bearing metallic phases reflecting the net magnetic properties of CEINS was characterized by powder X-ray diffraction (XRD), thermogravimetry (TGA), and vibrating sample magnetometry. The morphological and surface chemistry features were characterized by electron microscopy (transmission electron microscopy [TEM] and scanning electron microscopy [SEM]), Raman spectroscopy, and Fourier transform-infrared (FT-IR) spectroscopy. The textural properties of CEINS, including porosity, surface total charge density, and zeta potentials, were also measured. The as-synthesized different CEIN samples were finally examined as a potent MRI contrast drug candidate. Magnetic resonance relaxation measurements were performed in bovine gelatin-based phantom models by using a 1.5-T MRI scanner equipped with a standard radiofrequency “birdcage” type head coil. To obtain data, T1- and T2-weighted MR images were acquired using the inversion recovery spin echo (SE) and the SE protocol with multiple time of echo (TE), respectively. Chemical characterization showed similarity in morphology and textural properties between as-synthesized CEINS, purified CEINS, and CEINS functionalized with acidic groups. The as-synthesized CEINS had significantly higher Fe content and higher saturation magnetization. The analysis of the relaxometric properties of CEINS revealed that all the CEIN samples decreased T2 relaxation times on the T2-weighted images. The relaxation rate (1/T2) showed some differences between the as-synthesized, purified, and surface-functionalized CEINS containing surface carboxylic groups. Both the as-synthesized and purified CEINS slightly decreased the T1 relaxation times, which was evident through increase in the relaxation rates (1/T1). This study concludes that CEINS may represent a novel “core-shell”–type negative contrast drug candidate for MRI. It should be emphasized that all the studied CEIN samples have acceptable r2 relaxivities at the field strength of 1.5 T where most of the MRI systems operate in clinical radiology.

A novel immunosensor for transferrin (Tf) detection in blood samples has been developed. The stable layer of carbon-encapsulated magnetic nanoparticles containing carboxylic groups anchored with the monoclonal antibody ensured good electric contact for direct electron exchange between transferrin and the electrode surface. The interactions of the immobilized antibody with transferrin (at various concentration) were monitored via various responses, i.e.: voltammetric (reduction current of Tf), gravimetric (amplitude of frequency oscillations) and impedance (charge transfer resistance). For the determination of transferrin in blood samples the best procedure is the gravimetric one that gave the highest sensitivity. The obtained results show excellent linear response in the Tf concentration range between 5 × 10 −7 and 5 × 10 −2 g dL −1 (5 × 10 −3 ÷ 500 μg mL −1 ) with the detection limit of ca. 12.0 ± 1.8, 15.0 ± 2.4 and 24.0 ± 5.2 ng dL −1 for gravimetric, impedance and voltammetric analysis, respectively. The functionality of the electrochemical immunosensor has been also demonstrated during the analysis of the Tf level in rat blood samples.

An amendment to this paper has been published and can be accessed via the original article.

Fast, simple in use and highly effective voltammetric enantiosensor dedicated for determination of thalidomide (TD) enantiomers (especially towards the toxic (S)-enantiomer) in blood plasma is still desirable. Here we have proven that newly synthesized chiral naphthalene diimide (NDI) derivatives are excellent electroactive materials for TD enantiosensors. The recognition process relies on the specific interaction between the chiral NDI receptor and the thalidomide enantiomer of the opposite configuration. This unique specific interaction between (S)-thalidomide and (R)-NDI derivative counterparts, evident in the DPV voltammograms, was confirmed by molecular modeling. The demonstrated voltammetric enantiosensors are characterized by the low detection limit at the level of μg·L−1, wide analytical range from 5·10−4 – 10 mg·L−1, high selectivity and long lifetime. The results of the recovery rates showed a very good degree of accuracy towards the determination of (S)-thalidomide in the blood samples, so it can be successfully used in the analysis of clinical samples.

Protein interaction with polymers layers is a keystone in designing bio-nano devices. Polyamidoamines (PAMAMs) are well-known polymers. Zero aromatic core dendrimers (ZAC) are molecules with no proven toxic effect in cultured cells. When coating nanodevices with enzymatic systems, active sites are disturbed by an interaction with the biosystem surface. Computational methods were used in order to simulate, characterize, and quantify protein&ndash, polymer interaction. Protein corona, i.e., surface proteins disposed on a viral membrane or nanodevice outer surface, are crucial in interactions with a potential pharmacological target or receptor. Corona symmetry has been observed in the Middle East respiratory syndrome-related coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus (SARS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As a protein alpha 1 antitrypsin&rsquo, s a crystallographic structure was chosen. Protein&ndash, mono dendrimer layer systems were generated using in silico methods in order to simulate their interaction. Interactions were quantified using topological and quantum mechanical strategies. Results showed that PAMAM and ZAC interact differently with alpha 1 antitrypsin. Energy and topological surfaces of protein vary accordingly with the dendrimer monolayer. Topological surfaces have a higher sensibility in describing the interactions.

Simple, selective and sensitive analytical devices are of a great importance for medical application. Herein, we developed highly selective immunosensor for electrochemical detection of C-reactive protein (CRP) in blood sample. Branched polyethylenimine functionalized with ferrocene residues (PEI-Fc) was the main element of the recognition layer, which allowed: (i) covalent binding of an antibody in its most favorable orientation and (ii) voltammetric detection of the C-reactive protein. Anchoring of PEI-Fc to the electrode surface through the electrodeposition process leads to the formation of thin, stable and reproducible layers, which is extremely important in the case of electrochemical immunosensing. The proposed analytical device is characterized by high selectivity and sensitivity and can be successfully used in the concentration range of CRP from 1 to 5·104 ng mL−1. The determined limit of detection was circa 0.5 and 2.5 ng mL−1 for voltammetric and impedance analysis, respectively. The developed analytical device has also been successfully applied for the analysis of CRP level in rat blood samples.

Modification of the electrode surface by the ferromagnetic carbon-encapsulated iron nanoparticles (Fe@C Nps) and application of an external magnetic field allowed to obtain a highly efficient direct voltammetric sensor for ceruloplasmin (Cp) in blood. We managed to amplify the transport of Cp to the electrode surface modified with Fe@C Nps and, simultaneously, to control the orientation of Cp molecules that approach the electrode surface. Both facts are of key importance for the appearing of voltammetric signal. The intensity of this process strongly depends on the Cp concentration in the solution. The proposed Cp sensor is characterized by a linear response within a broad concentration range of Cp in the solution (0.002 and 0.05 mg L −1 ; r 2 = 0.998) and low detection limit (LODs: 2.3 ± 0.6 μg L −1 versus IUPAC model and 11.4 ± 2.4 μg L −1 versus Hubaux–Vos model, respectively). The sensor was found to be able to detect both the Cp protein and other paramagnetic molecules such as hemoglobin and transferrin in the same probe of the blood sample, without any interference in the assay during one fast measurement. The inductively coupled plasma mass spectrometry with laser ablation (LA-ICP-MS) and electrochemical quartz crystal microbalance (EQCM) studies revealed that after the oxidation process the protein molecules are strongly adsorbed directly onto the modified electrode surface. The developed voltammetric Cp sensor based on magnetic nanoparticles and working under the external low magnetic field is a new type of a diagnostic tool to be used as a quick one-step blood bioassay in modern nanomedicine.

An effective, fast, facile and direct electrochemical method of determination of hemoglobin (Hb) in blood sample without any sample preparation is described. The method is accomplished by using the ferromagnetic electrode modifier (carbon-encapsulated iron nanoparticles) and an external magnetic field. The successful voltammetric determination of hemoglobin is achieved in PBS buffer as well as in the whole blood sample. The obtained results show the excellent electroactivity of Hb. The measurements are of high sensitivity and good reproducibility. The detection limit is estimated to be 0.7 pM. The electrochemical determination data were compared with the gravimetric data obtained with a quartz crystal microbalance. The agreement between these results is very good. The changes of the electrode surface morphology before and after Hb detection are monitored by electron microscopy. The functionality of the electrochemical sensor is tested with human and rat blood samples. The concentration of hemoglobin in the blood samples determined by using voltammetric/gravimetric detection is in perfect agreement with the data obtained from typical clinical analysis.

Carbon-based nanomaterials functionalized by cationic polymers are interesting starting materials for the development of nanotheranostic systems. In this study, polyethylenimine (PEI) and its pre-synthesized derivatives were conjugated to carbon-encapsulated iron nanoparticles (CEINs). Branched PEIs of various molecular weight were derivatized. The aim of the polymer modification was to introduce carboxylic functionality to the PEI structure. Two different synthetic pathways were proposed: the amide-type reaction with succinic acid anhydride and reductive amination using p-formylbenzoic acid. The polyethylenimine derivatives were analyzed by means of spectroscopic methods (NMR and FT-IR). In order to determine the ratio of primary, secondary and tertiary amine groups in the modified polymers, inverted-gate 13C NMR spectroscopy was applied. Next, CEINs modified with two different surface carboxylic linkers were functionalized using pristine PEI and its derivatives. The conjugation of the polymer to the surface-modified nanoparticles was carried out using the carbodiimide–amine type reaction. The success of the conjugation process was confirmed by thermogravimetry and infrared spectroscopy. The morphological details were analyzed using transmission electron microscopy, whilst the surface zeta potential and the average particle size were determined by dynamic light scattering. It was found that the molecular weight of the polymer and the type of the surface linker were the key factors which crucially influenced the functionalization yield and the physicochemical features of the synthesized nanoplatforms. The best dispersion stability in aqueous media and the smallest mean hydrodynamic particle size was found for CEINs with the longer carboxylic linker.

The way of immobilization of the monoclonal antibody (type IgG) on the electrode surface has a significant effect on the amount of the immobilized protein and in consequence on current signal of protein. Herein, we demonstrate that the application of appropriately functionalized phenyl film allowed us to control the orientation of the antibody (Ab) molecules on the electrode surface. The influence of Ab orientation on the efficiency of antigen-antibody interaction was tested with an example blood plasma protein (ferritin; Ft). To control the orientation of Ab molecules the phenyl films containing –COOH or –NH2 groups were applied. Contrary to aminoethylophenyl layer, the carboxyphenyl film guaranteed the shortest distance between the redox center of the protein and the electrode surface. Additionally, the application of an external magnetic field together with magnetic nanoparticles allowed achieving the best orientation to observe well-defined ferritin current signals. The proposed method of ferritin detection can be successfully used in the concentration range of Ft between 0.1 and 30 µg dL−1. The detection limit for a carboxyphenyl film was estimated as 0.40 ± 0.04 and 0.13 ± 0.04 µg dL−1 for impedance and voltammetric measurements, respectively. In turn, for an aminoethylophenyl film the detection limit was 0.03 ± 0.002 (electrochemical impedance spectroscopy; EIS) and 0.02 ± 0.002 µg dL−1 (differential pulse voltammetry, DPV). The interday precision (reproducibility) was calculated (4.10 ÷ 9.10% RSD) together with the intraday precision / repeatability (3.20 ÷ 8.0% RSD) for the studied samples. The functionality of the sensor has been tested on rat blood samples. Based on the performed investigations it can be stated that the developed sensor was characterized by high selectivity and good sensitivity.

This work presents a very new look at folate targeting and is focused on synthesizing and assessing the biological activity of folic acid-targeted drug delivery materials based on β-cyclodextrin. Both folic acid and β-cyclodextrin have been covalently conjugated to branched polyethylenimine as the polymeric vector. Host-guest inclusion of folic acid into a β-cyclodextrin cavity, demonstrated by means of the spectroscopic methods (2-D NMR, IR, UV-Vis), is found to be of crucial importance for biological activity of nanotherapeutics. This paper describes the very first example of the versatile synthetic approach to create the polymeric biosystems, where folic acid activity is not limited by the inclusion phenomenon. Cytotoxicity of the obtained polymeric materials against Lewis lung carcinoma cells is determined by neutral red uptake assay. Folate receptor-binding studies reveal that the developed synthetic approach enables full exploitation of the potential of folic acid as a targeting ligand.

The immobilization of gamma-globulins from human and bovine blood and human polyclonal antibody (IgG) onto carbon-encapsulated iron nanoparticles (CEINs) is reported. First, the CEINs were functionalized to introduce the surface acidic linkers with a different length. The shorter linker was introduced by a typical oxidation treatment in concentrated acids. The longer linker was anchored by a free radical addition route, in which the radicals were generated by the thermal decomposition of succinic acid acyl peroxide. Both functionalization routes caused a partial perforation of the carbon coating. This structural degradation was determined quantitatively by evaluation the Fe content in the functionalized CEINs. Gamma-globulins and human polyclonal antibody (IgG) were immobilized onto the linker-functionalized surface using the carbodiimide–amine type reaction. The success of immobilization was confirmed by infrared spectroscopy, thermogravimetry and protein assay, respectively. The immune reactivity of the immobilized primary human polyclonal antibody (IgG) was also confirmed in a reaction with a FITC-labeled goat secondary antibody (anti-IgG) recognizing the primary human antibody in CEINs. It has been found that the immobilization yield is primarily dependent on the length of the acidic linker, whilst the content of carboxylic groups is of secondary importance.

Worldwide, drug-induced liver injury (DILI) is a major cause of hepatic failure. It is also the leading cause of withdrawal, cautionary labeling, and restricted usage of licensed drugs; therefore, European Medicines Agency (EMA) and United States Food and Drug Administration (FDA) warn that the existing methods of assessing DILI are insufficient and that some of the translational biomarkers of hepatotoxicity must be relooked. Magnetic resonance imaging (MRI) seems to be a proper tool in elucidating the effects of DILI in both preclinical and clinical studies, providing excellent visualization of the morphology of the liver parenchyma. Therefore, herein, we propose preclinical MRI assessment of liver injury in experimental paracetamol-treated rats. Quantitative MRI clearly provides evidence of adverse effects in the liver tissue caused by a single overdose of paracetamol (1 g kg−1 and 1.5 g kg−1 b.w.). The results of the MRI were confirmed by the histopathological examination (HE it has a potential to serve as the early diagnostic tool for the prediction of DILI in preclinical evaluation.

Objectives The purpose of this study was to assess the value of contrast-enhanced magnetic resonance cholangiography (MRC) performed in different time delays after injection of gadoxetic acid disodium (Gd-EOB-DTPA) for the diagnosis of active bile leak. Methods This retrospective analysis included Gd-EOB-DTPA enhanced MR images of 34 patients suspected of bile leak. Images were acquired 20–25 min after Gd-EOB-DTPA injection. If there was inadequate contrast in the bile ducts then delayed images after 60–90 min and 150–180 min were obtained. Results were correlated with intraoperative findings, ERCP results, clinical data, laboratory tests, and follow-up examinations. Results Gd-EOB-DTPA enhanced MRC yielded an overall sensitivity of 96.4%, specificity of 100% and accuracy of 97.1% for the diagnosis of an active bile leak. The sensitivity of 20–25 min delayed MR images was 42.9%, of combined 20–25 min and 60–90 min delayed images was 92.9% and of combined 20–25 min, 60–90 min and 150–180 min delayed images was 96.4%. Conclusions Gd-EOB-DTPA enhanced MRC utilizing delayed phase images was effective for detecting the presence and location of active bile leaks. The images acquired 60–180 min post-injection enabled identification of bile leaks even in patients with a dilated biliary system or moderate liver dysfunction.

Carbon-encapsulated iron nanoparticles (CEINs) have been considered as attractive candidates for several biomedical applications. In the present study, we synthesized CEINs (the mean diameter 40–80 nm) using a carbon arc route, and the as-synthesized CEINs were characterized (scanning and transmission electron microscopy, dynamic light scattering, turbidimetry, Zeta potential) and further tested as raw and purified nanomaterials containing the carbon surface modified with acidic groups. For cytotoxicity evaluation, we applied a battery of different methods (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase, calcein AM/propidium iodide, annexin V/propidium iodide, JC-1, cell cycle assay, Zeta potential, TEM and inductively coupled plasma mass spectrometry) to address the strategic cytotoxic endpoints of Lewis lung carcinoma cells due to CEIN (0.0001–100 µg ml–1) exposures in vitro. Our studies evidence that incubation of Lewis lung carcinoma cells with CEINs is accompanied in substantial changes of zeta potential in cells and these effects may result in different internalization profiles. The results show that CEINs increased the mitochondrial and cell membrane cytotoxicity; however, the raw CEIN material (Fe@C/Fe) produced higher toxicities than the rest of the CEINs studied to data. The study showed that non-modified CEINs (Fe@C/Fe and Fe@C) elevated some pro-apoptotic events to a greater extent compared to that of the surface-modified CEINs (Fe@C-COOH and Fe@C-(CH2)2COOH). They also diminished the mitochondrial membrane potentials. In contrast to non-modified CEINs, the surface-functionalized nanoparticles caused the concentration- and time-dependent arrest of the S phase in cells. Taken all together, our results shed new light on the rational design of CEINs, as their geometry, hydrodynamic and, in particular, surface characteristics are important features in selecting CEINs as future nanomaterials for nanomedicine applications. Copyright © 2013 John Wiley & Sons, Ltd.

OBJECTIVE:The aims of this study were to assess the sensitivity of various magnetic resonance imaging (MRI) sequences for the diagnosis of pulmonary nodules and to estimate the accuracy of MRI for the measurement of lesion size, as compared to computed tomography (CT). METHODS:Fifty patients with 113 pulmonary nodules diagnosed by CT underwent lung MRI and CT. MRI studies were performed on 1.5T scanner using the following sequences: T2-TSE, T2-SPIR, T2-STIR, T2-HASTE, T1-VIBE, and T1-out-of-phase. CT and MRI data were analyzed independently by two radiologists. RESULTS:The overall sensitivity of MRI for the detection of pulmonary nodules was 80.5% and according to nodule size: 57.1% for nodules ≤4mm, 75% for nodules >4-6mm, 87.5% for nodules >6-8mm and 100% for nodules >8mm. MRI sequences yielded following sensitivities: 69% (T1-VIBE), 54.9% (T2-SPIR), 48.7% (T2-TSE), 48.7% (T1-out-of-phase), 45.1% (T2-STIR), 25.7% (T2-HASTE), respectively. There was very strong agreement between the maximum diameter of pulmonary nodules measured by CT and MRI (mean difference -0.02 mm; 95% CI -1.6-1.57 mm; Bland-Altman analysis). CONCLUSIONS:MRI yielded high sensitivity for the detection of pulmonary nodules and enabled accurate assessment of their diameter. Therefore it may be considered an alternative to CT for follow-up of some lung lesions. However, due to significant number of false positive diagnoses, it is not ready to replace CT as a tool for lung nodule detection.

Carbon-encapsulated iron nanoparticles (CEINs) qualified as metal-inorganic hybrid nanomaterials offer a potential scope for an increasing number of biomedical applications. In this study, we have focused on the investigation of cellular fate and resulting cytotoxic effects of CEINs synthesized using a carbon arc route and studied in murine endothelial (HECa-10) cells. The CEIN samples were characterized as pristine (the mean diameter between 47 and 56nm) and hydrodynamic (the mean diameter between 270 and 460nm) forms and tested using a battery of methods to determine the cell internalization extent and cytotoxicity effects upon to the exposures (0.0001-100μg/ml) in HECa-10 cells. Our studies evidenced that the incubation with CEINs for 24h is accompanied with substantial changes of Zeta potential in cells which can be considered as a key factor for affecting the membrane transport, cellular distribution and cytotoxicity of these nanoparticles. The results demonstrate that CEINs have entered the endothelial cell through the endocytic pathway rather than by passive diffusion and they were mainly loaded as agglomerates on the cell membrane and throughout the cytoplasm, mitochondria and nucleus. The studies show that CEINs induce the mitochondrial and cell membrane cytotoxicities in a dose-dependent manner resulting from the internal dosages due to CEIN agglomerates. Our results highlight the importance of the physicochemical characterization of CEINs in studying the magnetic nanoparticle-endothelial cell interactions because the CEIN mass agglomerates can sediment more or less rapidly in culture models.

Background The aim of this study was to determine if the appearance of hepatic epithelioid hemangioendothelioma (HEHE) on state-of-the-art MRI including hepatocyte phase after administration of hepatobiliary contrast agent can facilitate preoperative diagnosis and identification of potential candidates for liver transplantation. Material and methods The study group comprised 6 patients with pathologically confirmed HEHE. Analysis included signal characteristics of 55 tumor nodules (maximum of 10 lesions per patient) on T2-weighted images, dynamic contrast-enhanced, 5-minute delayed, and hepatobiliary phase images. Results The most common feature of HEHE, observed in 84% of lesions, was progressive contrast-enhancement, followed by subcapsular location (66%), confluent appearance (60%) and hyper- or isointensity on hepatobiliary phase images (53%). In 5 of 6 patients, capsular retraction was observed. Conclusions The appearance of HEHE on hepatobiliary phase images was variable, but examined tumors often demonstrated hyper- or isointensity, most probably due to prolonged retention of contrast material. These features, along with typical morphology (subcapsular, confluent nodules, with progressive enhancement and capsular retraction), may contribute to correct diagnosis and recognition of potential candidates for liver transplantation.

Carbon-encapsulated iron nanoparticles (CEINs) have been considered as attractive candidates for several biomedical applications. In the present study, we synthesized CEINs (the mean diameter 40-80 nm) using a carbon arc route, and the as-synthesized CEINs were characterized (scanning and transmission electron microscopy, dynamic light scattering, turbidimetry, Zeta potential) and further tested as raw and purified nanomaterials containing the carbon surface modified with acidic groups. For cytotoxicity evaluation, we applied a battery of different methods (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase, calcein AM/propidium iodide, annexin V/propidium iodide, JC-1, cell cycle assay, Zeta potential, TEM and inductively coupled plasma mass spectrometry) to address the strategic cytotoxic endpoints of Lewis lung carcinoma cells due to CEIN (0.0001-100 µg ml(-1) ) exposures in vitro. Our studies evidence that incubation of Lewis lung carcinoma cells with CEINs is accompanied in substantial changes of zeta potential in cells and these effects may result in different internalization profiles. The results show that CEINs increased the mitochondrial and cell membrane cytotoxicity; however, the raw CEIN material (Fe@C/Fe) produced higher toxicities than the rest of the CEINs studied to data. The study showed that non-modified CEINs (Fe@C/Fe and Fe@C) elevated some pro-apoptotic events to a greater extent compared to that of the surface-modified CEINs (Fe@C-COOH and Fe@C-(CH2 )2 COOH). They also diminished the mitochondrial membrane potentials. In contrast to non-modified CEINs, the surface-functionalized nanoparticles caused the concentration- and time-dependent arrest of the S phase in cells. Taken all together, our results shed new light on the rational design of CEINs, as their geometry, hydrodynamic and, in particular, surface characteristics are important features in selecting CEINs as future nanomaterials for nanomedicine applications.

Carbon-encapsulated iron nanoparticles (CEINs) have recently emerged as a new class of magnetic nanomaterials with a great potential for an increasing number of biomedical applications. To address the current deficient knowledge of cellular responses due to CEIN exposures, we focused on the investigation of internalization profile and resulting cytotoxic effects of CEINs (0.0001–100 μg/ml) in murine glioma cells (GL261) in vitro . The studied CEIN samples were characterized (TEM, FT-IR, Zeta potential, Boehm titration) and examined as raw and purified nanomaterials with various surface chemistry composition. Of the four type CEINs (the mean diameter 47–56 nm) studied here, the as-synthesized raw nanoparticles (Fe@C/Fe) exhibited high cytotoxic effects on the plasma cell membrane (LDH, Calcein AM/PI) and mitochondria (MTT, JC-1) causing some pro-apoptotic evens (Annexin V/PI) in glioma cells. The effects of the purified (Fe@C) and surface-modified (Fe@C-COOH and Fe@C-(CH 2 ) 2 COOH) CEINs were found in quite similar patterns; however, most of these cytotoxic events were slightly diminished compared to those induced by Fe@C/Fe. The study showed that the surface-functionalized CEINs affected the cell cycle progression in both S and G2/M phases to a greater extent compared to that of the rest of nanoparticles studied to data. Taken all together, the present results highlight the importance of the rational design of CEINs as their physicochemical features such as morphology, hydrodynamic size, impurity profiles, and especially surface characteristics are critical determinants of different cytotoxic responses.

A chemical property space defines the adaptability of a molecule to changing conditions and its interaction with other molecular systems determining a pharmacological response. Within a congeneric molecular series (compounds with the same derivatization algorithm and thus the same brute formula) the chemical properties vary in a monotonic manner, i.e., congeneric compounds share the same chemical property space. The chemical property space is a key component in molecular design, where some building blocks are functionalized, i.e., derivatized, and eventually self-assembled in more complex systems, such as enzyme-ligand systems, of which (physico-chemical) properties/bioactivity may be predicted by QSPR/QSAR (quantitative structure-property/activity relationship) studies. The system structure is determined by the binding type (temporal/permanent; electrostatic/covalent) and is reflected in its local electronic (and/or magnetic) properties. Such nano-systems play the role of molecular devices, important in nano-medicine. In the present article, the behavior of polyethylenimine (PEI) macromolecules (linear LPEI and branched BPEI, respectively) with respect to the glucose oxidase enzyme GOx is described in terms of their (interacting) energy, geometry and topology, in an attempt to find the best shape and size of PEIs to be useful for a chosen (nanochemistry) purpose.

Purpose To assess and compare the incidence of abnormal findings detected during non-contrast-enhanced whole-body magnetic resonance imaging (WB-MRI) in the general population in two age groups: (1) 50 years old and younger; and (2) over 50 years old. Materials and Methods The analysis included 666 non-contrast-enhanced WB-MRIs performed on a 1.5-T scanner between December 2009 and June 2013 in a private hospital in 451 patients 50 years old and younger and 215 patients over 50 years old. The following images were obtained: T2-STIR (whole body-coronal plane), T2-STIR (whole spine-sagittal), T2-TSE with fat-saturation (neck and trunk-axial), T2-FLAIR (head-axial), 3D T1-GRE (thorax-coronal, axial), T2-TSE (abdomen-axial), chemical shift (abdomen-axial). Detected abnormalities were classified as: insignificant (type I), potentially significant, requiring medical attention (type II), significant, requiring treatment (type III). Results There were 3375 incidental findings depicted in 659 (98.9%) subjects: 2997 type I lesions (88.8%), 363 type II lesions (10.8%) and 15 type III lesions (0.4%), including malignant or possibly malignant lesions in seven subjects. The most differences in the prevalence of abnormalities on WB-MRI between patients 50 years old and younger and over 50 years old concerned: brain infarction (22.2%, 45.0% respectively), thyroid cysts/nodules (8.7%, 18.8%), pulmonary nodules (5.0%, 16.2%), significant degenerative disease of the spine (23.3%, 44.5%), extra-spinal degenerative disease (22.4%, 61.1%), hepatic steatosis (15.8%, 24.9%), liver cysts/hemangiomas (24%, 34.5%), renal cysts (16.9%, 40.6%), prostate enlargement (5.1% of males, 34.2% of males), uterine fibroids (16.3% of females, 37.9% of females). Conclusions Incidental findings were detected in almost all of the subjects. WB-MRI demonstrated that the prevalence of the vast majority of abnormalities increases with age.

To compare the efficacy of two quantitative methods for discrimination between benign and malignant focal liver lesions (FLLs): apparent diffusion coefficient (ADC) values and T2 relaxation times.Seventy-three patients with 215 confirmed FLLs (115 benign, 100 malignant) underwent 1.5-T MRI with respiratory-triggered single-shot SE DWI (b = 50, 400, 800) and dual-echo T2TSE (TR = 3,000 ms; TE1 = 84 ms; TE2 = 228 ms). ADC values and T2 relaxation times of FLLs were calculated. Sensitivity, specificity and accuracy of both techniques in diagnosing malignancy were assessed.The mean ADC value of malignant tumours (1.07 × 10(-3) mm(2)/s) was significantly lower (P 0.05) than that of benign lesions (1.86 × 10(-3) mm(2)/s ); however, with the use of the optimal cut-off value of 1.25 × 10(-3) mm(2)/s, 20 false positive (FP) and 20 false negative (FN) diagnoses of malignancy were noted, generating 79 % sensitivity, 82.6 % specificity and 80.9 % accuracy. The mean T2 relaxation time of malignant tumours (64.4 ms) was significantly lower (P 0.05) than that of benign lesions (476.1 ms). At the threshold of 107 ms 22 FP and 1 FN diagnoses were noted; the sensitivity was 99 %, specificity 80.9 % and accuracy 89.3 %.Quantitative analysis of T2 relaxation times yielded significantly higher sensitivity and accuracy in diagnosing malignant liver tumour than ADC values.• Diffusion-weighted magnetic resonance imaging is increasingly used for liver lesions. • But ADC values demonstrated only moderate accuracy for differentiation of liver lesions. • T2 relaxation times yielded higher accuracy in diagnosing malignant liver tumours. • Both ADC and T2 values overlapped between focal nodular hyperplasia and malignant lesions. • Nevertheless T2 liver mapping could be valuable for evaluating focal liver lesions.

Carbon-encapsulated iron nanoparticles (CEINs) are emerging as promising biomedical tools due to their unique physicochemical properties. In this study, the cytotoxic effect of CEINs (the mean diameter distribution ranges 46–56 nm) has been explored by MTT, LDH leakage, Calcein-AM/propidium iodide (PI) and Annexin V-FITC/PI assays in human melanoma (HTB-140), mouse melanoma (B16-F10) cells, and human dermal fibroblasts (HDFs). The results demonstrated that CEINs produce mitochondrial and cell membrane cytotoxicities in a dose (0.0001–100 μg/ml)-dependent manner. Moreover, the studies elucidated some differences in cytotoxic effects between CEINs used as raw and purified materials composing of the carbon surface with acidic groups. Experiments showed that HTB-140 cells are more sensitive to prone early apoptotic events due to raw CEINs as compared to B16-F10 or HDF cells, respectively. Taken together, these results suggest that the amount of CEINs administered to cells and the composition of CEINs containing different amounts of iron as well as the carbon surface modification type is critical determinant of cytotoxic responses in both normal and cancer (melanoma) cells. Electronic supplementary material The online version of this article (doi:10.1007/s11051-013-1835-7) contains supplementary material, which is available to authorized users.

Glucose oxidase (GOx) is an enzyme produced by Aspergillus, Penicillium and other fungi species. It catalyzes the oxidation of β-d-glucose (by the molecular oxygen or other molecules, like quinones, in a higher oxidation state) to form d-glucono-1,5-lactone, which hydrolyses spontaneously to produce gluconic acid. A coproduct of this enzymatic reaction is hydrogen peroxide (H2O2). GOx has found several commercial applications in chemical and pharmaceutical industries including novel biosensors that use the immobilized enzyme on different nanomaterials and/or polymers such as polyethylenimine (PEI). The problem of GOx immobilization on PEI is retaining the enzyme native activity despite its immobilization onto the polymer surface. Therefore, the molecular dynamic (MD) study of the PEI ligand (C14N8_07_B22) and the GOx enzyme (3QVR) was performed to examine the final complex PEI-GOx stabilization and the affinity of the PEI ligand to the docking sites of the GOx enzyme. The docking procedure showed two places/regions of major interaction of the protein with the polymer PEI: (LIG1) of −5.8 kcal/mol and (LIG2) of −4.5 kcal/mol located inside the enzyme and on its surface, respectively. The values of enthalpy for the PEI-enzyme complex, located inside of the protein (LIG1) and on its surface (LIG2) were computed. Docking also discovered domains of the GOx protein that exhibit no interactions with the ligand or have even repulsive characteristics. The structural data clearly indicate some differences in the ligand PEI behavior bound at the two places/regions of glucose oxidase.