Comparative studies on the cytotoxic effects induced by iron oxide nanoparticles in cancerous and noncancerous human lung cells subjected to an alternating magnetic field

The cytotoxic effects of water-based ferrofluids composed of iron oxide nanoparticles, including magnetite (Fe3O4) and maghemite (γ-Fe2O3), ranging from 15 to 100 nm, were examined on various lung cancer cells including adenocarcinomic human alveolar basal epithelial cells (A549), nonsmall lung squamous cell carcinoma (H1703), small cell lung cancer cells (DMS 114), and normal bronchial epithelial cells (BEAS-2B). The cytotoxic effect was evaluated both with and without exposure to an alternating magnetic field (AMF). The studies revealed that neither AMF nor iron oxide nanoparticles when tested individually, produced cytotoxic effects on either cancerous or noncancerous cells. However, when applied together, they led to a significant decrease in cell viability and proliferative capacity due to the enhanced effects of magnetic fluid hyperthermia (MFH). The most pronounced effects were found for maghemite (<50 nm) when subjected to an AMF. Notably, A549 cells exhibited the highest resistance to the proposed hyperthermia treatment. BEAS-2B cells demonstrated susceptibility to magnetized iron oxide nanoparticles, similar to the response observed in lung cancer cells. The studies provide evidence that MFH is a promising strategy as a standalone treatment for different types of lung cancer cells. Nevertheless, to prevent any MFH-triggered adverse effects on normal lung cells, targeted magnetic ferrofluids should be designed.

Monoclonal antibody-navigated carbon-encapsulated iron nanoparticles used for MRI-based tracking integrin receptors in murine melanoma

Integrin beta-3 is a cell adhesion molecule that mediate cell-to-cell and cell-to-extracellular matrix communication. The major goal of this study was to explore melanoma cells (B16F10) based upon specific direct targeting of the β3 subunit (CD61) in the integrin αvβ3 receptor using carbon-encapsulated iron nanoparticles decorated with monoclonal antibodies (Fe@C-CONH-anti-CD61 and Fe@C-(CH2)2-CONH-anti-CD61). Both melanoma cells treated with nanoparticles as well as C57BL/6 mice bearing syngeneic B16-F10 tumors intravenously injected with nanoparticles were tested in preclinical MRI studies. The as-synthesized carbon-encapsulated iron nanoparticles functionalized with CD61 monoclonal antibodies have been successfully used as a novel targeted contrast agent for MRI-based tracking melanoma cells expressing the β3 subunit of the integrin αvβ3 receptor.

Oxidation-derived anticancer potential of sumanene-ferrocene conjugates

An effective synthetic protocol towards the oxidation of sumanene-ferrocene conjugates bearing one to four ferrocene moieties has been established. The oxidation protocol was based on the transformation of FeII from ferrocene to FeIII-containing ferrocenium cations by means of the treatment of the title organometallic buckybowls with a mild oxidant. Successful isolation of these ferrocenium-tethered sumanene derivatives 5-7 gave rise to the biological evaluation of the first, buckybowl-based anticancer agents, as elucidated by in vitro assays with human breast adenocarcinoma cells (MDA-MB-231) and embryotoxicity trials in zebrafish embryos supported with in silico toxicology studies. The designed ferrocenium-tethered sumanene derivatives featured attractive properties in terms of their use in cancer treatments in humans. The tetra-ferrocenium sumanene derivative 7 featured especially beneficial biological features, elucidated by low (<40% for 10 μM) viabilities of MDA-MB-231 cancer cells together with a 1.4-1.7-fold higher viability of normal cells (human mammary fibroblasts, HMF) for respective concentrations. Compound 7 featured significant cytotoxicity against cancer cells thanks to the presence of sumanene and ferrocenium moieties; the latter motif also provided the selectivity of anticancer action. The biological properties of 7 were also improved in comparison with those of native building blocks, which suggested the effects of the presence of the sumanene skeleton towards the anticancer action of this molecule. Ferrocenium-tethered sumanene derivatives exhibited potential towards the generation of reactive oxygen species (ROS), responsible for biological damage to the cancer cells, with the most efficient generation of the tetra-ferrocenium sumanene derivative 7. Derivative 7 also did not show any embryotoxicity in zebrafish embryos at the tested concentrations, which supports its potential as an effective and cancer-specific anticancer agent. In silico computational analysis also showed no chromosomal aberrations and no mutation with AMES tests for the compound 7 tested with and without microsomal rat liver fractions, which supports its further use as a potent drug candidate in detailed anticancer studies.

In Silico Studies of Novel Vemurafenib Derivatives as BRAF Kinase Inhibitors

BRAF inhibitors have improved the treatment of advanced or metastatic melanoma in patients that harbor a BRAF^T1799A mutation. Because of new insights into the role of aberrant glycosylation in drug resistance, we designed and studied three novel vemurafenib derivatives possessing pentose-associated aliphatic ligands-methyl-, ethyl-, and isopropyl-ketopentose moieties-as potent BRAF_V600E kinase inhibitors. The geometries of these derivatives were optimized using the density functional theory method. Molecular dynamic simulations were performed to find interactions between the ligands and BRAF_V600E kinase. Virtual screening was performed to assess the fate of derivatives and their systemic toxicity, genotoxicity, and carcinogenicity. The computational mapping of the studied ligand-BRAF_V600E complexes indicated that the central pyrrole and pyridine rings of derivatives were located within the hydrophobic ATP-binding site of the BRAF_V600E protein kinase, while the pentose ring and alkyl chains were mainly included in hydrogen bonding interactions. The isopropyl-ketopentose derivative was found to bind the BRAF_V600E oncoprotein with more favorable energy interaction than vemurafenib. ADME-TOX in silico studies showed that the derivatives possessed some desirable pharmacokinetic and toxicologic properties. The present results open a new avenue to study the carbohydrate derivatives of vemurafenib as potent BRAF_V600E kinase inhibitors to treat melanoma.

Parallel SPR and QCM-D Quantitative Analysis of CD9, CD63, and CD81 Tetraspanins: A Simple and Sensitive Way to Determine the Concentration of Extracellular Vesicles Isolated from Human Lung Cancer Cells

Tetraspanins, including CD9, CD63, and CD81, are transmembrane biomarkers that play a crucial role in regulating cancer cell proliferation, invasion, and metastasis, as well as plasma membrane dynamics and protein trafficking. In this study, we developed simple, fast, and sensitive immunosensors to determine the concentration of extracellular vesicles (EVs) isolated from human lung cancer cells using tetraspanins as biomarkers. We employed surface plasmon resonance (SPR) and quartz crystal microbalance with dissipation (QCM-D) as detectors. The monoclonal antibodies targeting CD9, CD63, and CD81 were oriented vertically in the receptor layer using either a protein A sensor chip (SPR) or a cysteamine layer that modified the gold crystal (QCM-D) without the use of amplifiers. The SPR studies demonstrated that the interaction of EVs with antibodies could be described by the two-state reaction model. Furthermore, the EVs' affinity to monoclonal antibodies against tetraspanins decreased in the following order: CD9, CD63, and CD81, as confirmed by the QCM-D studies. The results indicated that the developed immunosensors were characterized by high stability, a wide analytical range from 6.1 × 10⁴ particles·mL^-1 to 6.1 × 10⁷ particles·mL^-1, and a low detection limit (0.6-1.8) × 10⁴ particles·mL^-1. A very good agreement between the results obtained using the SPR and QCM-D detectors and nanoparticle tracking analysis demonstrated that the developed immunosensors could be successfully applied to clinical samples.

Graphene-encapsulated iron nanoparticles as a non-viral vector for gene delivery into melanoma cells

The rapid progress of nanotechnology has led to use different nanomaterials for biomedical applications. Among them, graphene-encapsulated magnetic nanoparticles (GEMNS) are recognized as next generation carbon nanomaterials in translation cancer research. In this study, we utilized green fluorescence protein (GFP) expression plasmid DNA (pDNA) and GEMNS decorated with branched polyethyleneimine (PEI) to yield a novel transporter (GEMNS-PEI/pDNA) for gene delivery into melanoma cells (B16F10). The efficiency of transfection was examined using PCR and confocal microscopy. The studies show that the as-designed GEMNS-PEI construct is successfully used to transfect the melanoma cells with pDNA and it should be considered as a potent non-viral vector for introducing naked nucleic acids into eucaryotic cells.

Application of biocompatible and ultrastable superparamagnetic iron(III) oxide nanoparticles doped with magnesium for efficient magnetic fluid hyperthermia in lung cancer cells

Magnetic fluid hyperthermia (MFH) is a promising therapeutic strategy that targets malignant tissues by heating to 40-43 °C using magnetic nanoparticles (MNPs) subjected to an alternating magnetic field (AMF). In this study, novel magnetic iron(III) oxide nanoparticles doped with magnesium (Mg_0.1-γ-Fe₂O₃(mPEG-silane)_0.5) were synthesized, and their structural, chemical, and magnetic properties were analyzed using the following techniques: Fourier-transform infrared spectroscopy, Raman spectroscopy, vibrating magnetometer analysis, powder X-ray diffraction, inductively coupled plasma mass spectrometry, scanning electron microscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The as-synthesized MNPs were used as water ferrofluids for MFH under an AMF in two calorimetric setups, namely phantom and lung cancer cell (A549) models. The as-synthesized MNPs were hexagonal or rhombohedral shaped, with an average size of 27 nm. They showed a typical soft ferromagnetic behavior based on the hysteresis profile, with a magnetic saturation of 70 emu g^-1 and remnant magnetization of 1.6 emu g^-1. In phantom studies, the ferrofluid (3.0 mg mL^-1) exposed to an AMF (18.3 kA m^-1, 110.1 kHz) heated up extremely quickly, reaching more than 90 °C in the first 10 min of magnetization. In cell studies, the ferrofluid (0.25 mg mL^-1) under an AMF (16.7 kA m^-1, 110.1 kHz) showed a slight increase in temperature within the first 12 min, reaching a peak of ca. 43-45 °C, which was stable up to the end of the AMF exposure (45 min). Under these conditions, a pronounced cytotoxic effect on the lung cancer cells was observed (viability ca. 15-20%). No such deleterious effects were observed when the cells were treated with MNPs only without an AMF. Specific absorption rate (SAR) measurements were performed using three mathematical approaches, namely the initial slope method, the corrected slope method, and the Box-Lucas method, which ranged from ca. 429 to 596 W g^-1 for phantom and cell studies. Iron(III) oxide MNPs doped with magnesium were found to be candidates for MFH in lung cancer treatments.

Exosomes derived from lung cancer cells: Isolation, characterization, and stability studies

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.

Ultrasensitive voltammetric detection of SARS-CoV-2 in clinical samples

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^-7 to 0.20 mg·L^-1) and low detection limit (8.0·10^-8 mg·L^-1 ≡ 0.08 pg·mL^-1 ≡ 4 virions·μL^-1). The utility of the designed device was also evidenced by the detection of SARS-CoV-2 in the clinical samples. Moreover, the main advantage and a huge novelty of the developed device, compared to those already existing, is the moment of generating the analytical signal of the redox probe that appears only after the virus recognition. Thus, our diagnostic innovation may considerably contribute to controlling the COVID-19 pandemic. The as-developed immunosensor may well offer a novel alternative approach for viral detection that could complement or even replace the existing methods.

Novel electrogravimetric biosensors for the ultrasensitive detection of plasma matrix metalloproteinase-2 considered a potential tumor biomarker

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^-1 to 5.0 μg mL^-1), and low detection limit (ca. 10 fg mL^-1). They also exhibited excellent efficiency in the determination of active MMP-2 in real samples, such as blood plasma. The developed sensors may hold great promise for the early diagnosis of cancers.

Enzymatic cleavage of specific dipeptide conjugated with ferrocene as a flexible ultra-sensitive and fast voltammetric assay of matrix metalloproteinase-9 considered a prognostic cancer biomarker in plasma samples

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.

Correction to: Quantum dots as targeted doxorubicin drug delivery nanosystems in human lung cancer cells

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

Enantioselective sensing of (S)-Thalidomide in blood plasma with a chiral naphthalene diimide derivative

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.

MRI-based preclinical discovery of DILI: A lesson from paracetamol-induced hepatotoxicity

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 (H&E) of the rat liver specimen, however the adverse effects were not disclosed due to standard aminotransferase assays (ALT/AST) in rat blood serum. The results of our analysis demonstrate the successful application of MRI in the examination of paracetamol-induced hepatotoxicity in rats; it has a potential to serve as the early diagnostic tool for the prediction of DILI in preclinical evaluation.

Microfluidics for studying metastatic patterns of lung cancer

The incidence of lung cancer continues to rise worldwide. Because the aggressive metastasis of lung cancer cells is the major drawback of successful therapies, the crucial challenge of modern nanomedicine is to develop diagnostic tools to map the molecular mechanisms of metastasis in lung cancer patients. In recent years, microfluidic platforms have been given much attention as tools for novel point-of-care diagnostic, an important aspect being the reconstruction of the body organs and tissues mimicking the in vivo conditions in one simple microdevice. Herein, we present the first comprehensive overview of the microfluidic systems used as innovative tools in the studies of lung cancer metastasis including single cancer cell analysis, endothelial transmigration, distant niches migration and finally neoangiogenesis. The application of the microfluidic systems to study the intercellular crosstalk between lung cancer cells and surrounding tumor microenvironment and the connection with multiple molecular signals coming from the external cellular matrix are discussed. We also focus on recent breakthrough technologies regarding lab-on-chip devices that serve as tools for detecting circulating lung cancer cells. The superiority of microfluidic systems over traditional in vitro cell-based assays with regard to modern nanosafety studies and new cancer drug design and discovery is also addressed. Finally, the current progress and future challenges regarding printable and paper-based microfluidic devices for personalized nanomedicine are summarized.

Nanocomposites as biomolecules delivery agents in nanomedicine

Nanoparticles (NPs) are atomic clusters of crystalline or amorphous structure that possess unique physical and chemical properties associated with a size range of between 1 and 100 nm. Their nano-sized dimensions, which are in the same range as those of vital biomolecules, such as antibodies, membrane receptors, nucleic acids, and proteins, allow them to interact with different structures within living organisms. Because of these features, numerous nanoparticles are used in medicine as delivery agents for biomolecules. However, off-target drug delivery can cause serious side effects to normal tissues and organs. Considering this issue, it is essential to develop bioengineering strategies to significantly reduce systemic toxicity and improve therapeutic effect. In contrast to passive delivery, nanosystems enable to obtain enhanced therapeutic efficacy, decrease the possibility of drug resistance, and reduce side effects of "conventional" therapy in cancers. The present review provides an overview of the most recent (mostly last 3 years) achievements related to different biomolecules used to enable targeting capabilities of highly diverse nanoparticles. These include monoclonal antibodies, receptor-specific peptides or proteins, deoxyribonucleic acids, ribonucleic acids, [DNA/RNA] aptamers, and small molecules such as folates, and even vitamins or carbohydrates.

MR Imaging of Pulmonary Nodules: Detection Rate and Accuracy of Size Estimation in Comparison to Computed Tomography

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.

Sulfhydrylated graphene-encapsulated iron nanoparticles directly aminated with polyethylenimine: a novel magnetic nanoplatform for bioconjugation of gamma globulins and polyclonal antibodies

A graphene layer was directly aminated with polyethylenimine and a novel magnetic nanoplatform for bioconjugation of biologically active compounds was obtained.

Non-contrast-enhanced whole-body magnetic resonance imaging in the general population: the incidence of abnormal findings in patients 50 years old and younger compared to older subjects

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.

Assessing carbon-encapsulated iron nanoparticles cytotoxicity in Lewis lung carcinoma cells

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.

Cytotoxicity evaluation of carbon-encapsulated iron nanoparticles in melanoma cells and dermal fibroblasts

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.

Diallyl sulfide--a flavour component from garlic (Allium sativum) attenuates lipid peroxidation in mice infected with Trichinella spiralis

We investigated the antioxidant capacity of diallyl sulfide (DAS) in the course of experimental trichinellosis in C3H mice. For this purpose, the mice were orally infected with either Trichinella spiralis larvae (300 larvae/mouse) or treated per os with normal saline (control), and 12 hrs later, they were treated per os with DAS (200 mg/kg b.w) daily for 5 or 20 days. On day 5 and 35 of the post-infection period (5 and 35 dpi), thiobarbituric-acid reactive substances (TBARS) in the small intestinal mucosa and diaphragm samples and the total antioxidant status (TAS) of blood were determined. Trichinella spiralis increased TBARS and decreased TAS in the intestinal phase of invasion. However, in the muscular phase mice, neither TBARS nor TAS was found to be different from those of the control. Diallyl sulfide has been shown to decrease TBARS and the agent did not have any effect(s) on the total antioxidant status of blood in Trichinella-infected mice. The results suggest that diallyl sulfide may be an effective antioxidant candidate and may therefore play a significant role in the defense against lipid peroxidation in trichinellosis.

Evidence of 14C-furazolidone metabolite binding to the hepatic DNA of trout

Furazolidone (FZ) is a nitrofuran drug commonly used in aquaculture. In the present study, [methylidene-14C]-FZ or [oxazolone-4,5-14C]-FZ was offered to rainbow trout (Oncorhyncus mykiss) in medicated feed at a daily dose of 135 mg/kg b. wt. for 10 days. The trout were sacrificed at specific time points post-dosing and the liver removed for DNA-bound 14C characterization. Both forms of the 14C-labelled FZ were converted by trout to reactive metabolite(s) which bound irreversibly to the hepatic DNA. The amount of 14C bound to the hepatic DNA increased with post-dosing time and was higher in trout pretreated with [methylidene-14C]-FZ than in trout pretreated with [oxazolone-4,5-14C]-FZ. The identity of the FZ reactive metabolite(s) remained to be elucidated. However, a part of the FZ reactive metabolite(s) could be released as 3-amino-2-oxazolidone by acid hydrolysis. An appreciable amount of 14C was also found to bind irreversibly with the hepatic DNA of trout following an i.v. injection of [oxazolone-4,5-14C]-FZ. Results of these studies indicate that FZ is metabolized by trout to a reactive metabolite(s) which binds irreversibly to the DNA of trout liver.

Nitrite mediated T lymphocyte responses in the intestinal immune system of mice infected with Trichinella spiralis nematode

The effects of orally administered sodium nitrite (20 mg NaNO2/kg b. w) on the responses of T and B lymphocytes collected from the mesenteric lymph nodes were studied in resistant AKR/J, H-2(k) haplotype mice infected with Trichinella spiralis nematode. On days 6, 9, and 12 postinfection, the mesenteric lymph node cells (MLNC) were collected from the mice and assayed for lymphocyte subsets (CD4(+), CD8(+), B220(+)), cytokines (IL-2, IL-5), and INF-gamma. At the same time, the number of adult worms in the small intestine were counted. Infection of the nitrite-treated mice with T. spiralis L1 larvae caused a marked increase in the number of adult worms in the small intestine. However, preincubation of T. spiralis L1 larvae with nitrite before infecting the mice resulted in a significant reduction in the number of adult worms (p < 0.05). Preincubation of T. spiralis L1 larvae with nitrite also caused an increase in the number of CD4(+) and CD8(+) cells as well as IL-2, IL-5, and INF-gamma levels. An increased level of CD8(+) subsets and a depression of IL-2 and IL-5 production by MLNC were observed in mice infected with larvae without nitrite pretreatment. Since supplementary rIL-1alpha was found to alter INF-gamma secretion by MLNC in vitro, the pattern of MLNC proliferation was examined further with the nitrite-treated mice. Sodium nitrite increased thymidine incorporation into the MLNC. However, INF-gamma production was not enhanced when rIL-1alpha was added to the MLNC culture obtained from nitrite-treated mice.