Carbon nanotubes (CNT) and nano-graphite (NG) are graphene-based nanomaterials which share exceptional physicochemical properties, but whose health impacts are unfortunately still not well ...understood. On the other hand, carbon black (CB) is a conventional and widely studied material. The comparison of these three carbon-based nanomaterials is thus of great interest to improve our understanding of their toxicity. An acid functionalization was carried out on CNT, NG and CB so that, after a thorough characterization, their impacts on RAW 264.7 macrophages could be compared for a similar surface chemistry (15 to 120μg·mL−1 nanomaterials, 90-min to 24-h contact). Functionalized nanomaterials triggered a weak cytotoxicity similar to the pristine nanomaterials. Acid functionalization increased the pro-inflammatory response except for CB which did not trigger any TNF-α production before or after functionalization, and seemed to strongly decrease the oxidative stress. The toxicological impact of acid functionalization appeared thus to follow a similar trend whatever the carbon-based nanomaterial. At equivalent dose expressed in surface and equivalent surface chemistry, the toxicological responses from murine macrophages to NG were higher than for CNT and CB. It seemed to correspond to the hypothesis of a platelet and fiber paradigm.
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•Carbon nanotubes (CNT), carbon black (CB) and nano-graphite (NG) were functionalized.•For all, acid functionalization triggered the same impacts on macrophages.•We compared their in vitro toxicity for a similar surface dose and chemistry.•The macrophage response to functionalized NG was higher than for CB and CNT.
Increasing consumption of engineered nanoparticles and occupational exposure to novel, ultrafine airborne particles during the last decades has coincided with deterioration of sperm parameters and ...delayed fecundity. In order to prevent possible adverse health effects and ensure a sustainable growth for the nanoparticle industry, the ability to investigate the nanosized, mineralogical load of human reproductive systems is becoming a real clinical need. Toward this goal, the current study proposes two methods for the detection and quantification of engineered nanoparticles in human follicular and seminal fluid, developed with the use of well-defined 60 nm Au particles. Despite the complexity of these biological fluids, simple physical and chemical treatments allow for the precise quantification of more than 50 and 70% wt of the spiked Au nanoparticles at low μg ml
levels in follicular and seminal fluids, respectively. The use of electron microscopy for the detailed observation of the detected analytes is also enabled. The proposed method is applied on a small patient cohort in order to demonstrate its clinical applicability by exploring the differences in the metal and particulate content between patients with normal and low sperm count.
The knowledge of where particles deposit in the respiratory tract is crucial for understanding the health effects associated with inhaled drug particles.
An ex vivo study was conducted to assess ...regional deposition patterns (thoracic vs. extrathoracic) of radioactive polydisperse aerosols with different size ranges 0.15 μm-0.5 μm, 0.25 μm-1 μm and 1 μm-9 μm. SPECT/CT analyses were performed complementary in order to assess more precisely the regional deposition of aerosols within the pulmonary tract. Experiments were set using an original respiratory tract model composed of a human plastinated head connected to an ex vivo porcine pulmonary tract. The model was ventilated by passive expansion, simulating pleural depressions. Aerosol was administered during nasal breathing.
Planar scintigraphies allowed to calculate the deposited aerosol fractions for particles in the three size ranges from sub-micron to micron The deposited fractions obtained, for thoracic vs. extra-thoracic regions respectively, were 89 ± 4 % vs. 11 ± 4 % for 0.15 μm-0.5 μm, 78 ± 5 % vs. 22 ± 5 % for 0.25 μm-1 μm and 35 ± 11 % vs.65 ± 11 % for 1 μm-9 μm.
Results obtained with this new ex vivo respiratory tract model are in good agreement with the in vivo data obtained in studies with baboons and humans.
Molecular testing on metastatic lung adenocarcinoma or on non-small cell non-squamous lung carcinoma often relies on small specimen. In this group of patient with poor specimen adequacy, we analyzed ...the rate of EGFR, KRAS, BRAF and HER2 mutations compared to their rate in optimal specimen. We analyzed discrepancies in molecular testing results in patients with iterative analysis on several samples.
We performed a retrospective study of 1538 samples consecutively analyzed. 263/665 (39,5%) biopsies and 37/708 (5,2%) surgical specimens were considered as samples with poor specimen adequacy (p<0,0001). A lower tumor cell content was associated with a lower rate of KRAS mutation: 15,8% in samples with <10% of tumor cells or <100 tumor cells versus 29,8% in samples with >10% tumor cell and >100 tumor cells (p=0,001). KRAS mutational rate was at 11,1% in cytology specimens, significantly lower than in biopsy or surgical specimens respectively at 28,2% and 28,5% (p=0,0002). Tumor cell content was not associated with mutational rate for EGFR, BRAF and HER2 mutations. DNA quantity was not associated with mutational rate for EGFR, KRAS, BRAF and HER2.
A discrepancy in molecular testing was found in 16 patients. For 5 patients there was also a discrepancy for TTF-1 expression. On the 11 without TTF-1 discrepancy, specimen adequacy was not fulfilled in 10 cases at least for tumor content. Discrepancies were found in the case of low cellularity, poor cell content or testing on cytological specimens.
Tumor cell content is a crucial parameter for molecular analysis rather than the type of specimen or the DNA quantity. Discrepancies in molecular testing results are rare but might suggest the presence of another tumor type, the emergence of another clone or a molecular testing in a sample with low cell content.
•Tumor cell content is a crucial parameter for molecular analysis.•Discrepancies are rare and related to another clone/tumor or low tumor cell content.•Mutational analysis is often reliable in poor specimen adequacy.
The impact of 100Hz (Hertz) acoustic frequency airflow on sinus drug deposition of aerosols was investigated using a human plastinated nasal cast. The influence of drug concentration and endonasal ...anatomical features on the sinus deposition enhanced by the 100Hz acoustic airflow was also examined.
Plastinated models were anatomically, geometrically and aerodynamically validated (endoscopy, CT scans, acoustic rhinometry and rhinomanometry). Using the gentamicin as a marker, 286 experiments of aerosol deposition were performed. Changes of airborne particles metrology produced under different nebulization conditions (100Hz acoustic airflow and gentamicin concentration) were also examined.
Aerodynamic and geometric investigations highlighted a global behaviour of plastinated models in perfect accordance with a nasal decongested healthy subject. The results of intrasinus drug deposition clearly demonstrated that the aerosols can penetrate into the maxillary sinuses. The 100Hz acoustic airflow led to increase the deposition of drug into the maxillary sinuses by a factor 2–3 depending on the nebulization conditions. A differential intrasinus deposition of active substance depending on maxillary ostium anatomical features and drug concentration was emphasized.
The existence of a specific transport mechanism of penetration of nebulized particles delivered with acoustic airflow was proposed.
Type I interferons are essential for host response to viral infections, while dysregulation of their response can result in autoinflammation or autoimmunity. Among IFNα (alpha) responses, 13 subtypes ...exist that signal through the same receptor, but have been reported to have different effector functions. However, the lack of available tools for discriminating these closely related subtypes, in particular at the protein level, has restricted the study of their differential roles in disease. We developed a digital ELISA with specificity and high sensitivity for the IFNα2 subtype. Application of this assay, in parallel with our previously described pan-IFNα assay, allowed us to study different IFNα protein responses following cellular stimulation and in diverse patient cohorts. We observed different ratios of IFNα protein responses between viral infection and autoimmune patients. This analysis also revealed a small percentage of autoimmune patients with high IFNα2 protein measurements but low pan-IFNα measurements. Correlation with an ISG score and functional activity showed that in this small sub group of patients, IFNα2 protein measurements did not reflect its biological activity. This unusual phenotype was partly explained by the presence of anti-IFNα auto-antibodies in a subset of autoimmune patients. This study reports ultrasensitive assays for the study of IFNα proteins in patient samples and highlights the insights that can be obtained from the use of multiple phenotypic readouts in translational and clinical studies.
Bronchoalveolar lavage (BAL) is a diagnostic procedure which samples the cellular and non-cellular components of the pulmonary epithelial surface. The inherent biological noise of BAL fluids inhibits ...their direct mineralogical analysis while currently available particle retrieval protocols are suspected to impose quantitative and qualitative bias on the studied particle load. This study presents a simple method for the near-lossless extraction of citrate-capped gold nanoparticles from human BAL fluids at sub-ppm levels which enables their quantitation and surface characterization. This procedure was modeled according to fundamental principles of particle sedimentation and liquid-liquid interdiffusion and was evaluated by a battery of analytical techniques. The extraction yield of gold nanoparticles ranged from 61 to 86%, with a quantitation limit at 0.5 μg ml
, as measured by inductively-coupled optical emission spectroscopy. Dynamic light scattering could resolve the hydrodynamic size distribution of extracted particles which returned significantly different photon count rates at various concentrations. Their shape and primary size were easily observable by electron microscopy while atomic force microscopy, Auger electron spectroscopy and X-ray photoelectron spectroscopy could respectively probe the particles' biomolecular corona, detect surface-adsorbed S- and N- species, and identify carbon-based covalent bonds.
Acid functionalization has been considered as an easy way to enhance the dispersion and biodegradation of carbon nanotubes (CNT). However, inconsistencies between toxicity studies of acid ...functionalized CNT remain unexplained. This could be due to a joint effect of the main physicochemical modifications resulting from an acid functionalization: addition of surface acid groups and purification from catalytic metallic impurities. In this study, the impact on CNT biotoxicity of these two physiochemical features was assessed separately. The in vitro biological response of RAW 264.7 macrophages was evaluated after exposure to 15–240 µg mL
−1
of two types of multi-walled CNT. For each type of CNT (small: 20 nm diameter, and big: 90 nm diameter), three different surface chemical properties were studied (total of six CNT samples): pristine, acid functionalized and desorbed. Desorbed CNT were purified by the acid functionalization but presented a very low amount of surface acid groups due to a thermal treatment under vacuum. A Janus effect of acid functionalization with two opposite impacts is highlighted. The CNT purification decreased the overall toxicity, while the surface acid groups intensified it when present at a specific threshold. These acid groups especially amplified the pro-inflammatory response. The threshold mechanism which seemed to regulate the impact of acid groups should be further studied to determine its value and potential link to the other physicochemical state of the CNT. The results suggest that, for a safer-design approach, the benefit-risk balance of an acid functionalization has to be considered, depending on the CNT primary state of purification. Further research should be conducted in this direction.
Graphical abstract
Data about the expression of Epidermal Growth Factor Receptors (EGFRs) in colorectal adenomas remain scarce.
101 patients were enrolled including 53 controls. All adenomas (n = 38) and CRC (n = 5) ...were EGFR positive. Hyperplastic polyps (HP) (n = 8) and control colons (n = 53) were EGFR negative in half of cases (p < 0.0001). A well significant gradient of increased EGFR expression was observed between adjacent mucosa, hyperplastic lesions, low grade dysplasia (LGD) (n = 30), high grade dysplasia (HGD) adenomas (n = 9) and cancers (p < 0.0001). EGFR overexpression was reported in 100% of cancers, 77.8% of HGD, and 10% of LGD adenomas. By multivariate analysis in adenomas, associated factors with EGFR overexpression were HGD and tubulo-villous feature.
All patients undergoing colonoscopy in the university center of Saint-Etienne were eligible to the study from December 2015 to March 2016. In patients with colorectal neoplasia (lesions group), biopsies were performed on the lesion before its resection, and on the adjacent and distal colon mucosa. In control group, biopsies were performed in the right and left side colon. The EGFR expression was assessed by immunohistochemical scores (Goldstein grade, intensity of staining, composite score), using a primary mouse monoclonal antibody (EGFR, clone 113, Novocastra). Outcomes were compared using Kruskal-Wallis and/or Mann-Whitney-U tests, appropriately. The associated clinical, endoscopic and histological factors with EGFR overexpression (composite score ≥ 6) were assessed for adenomas by logistic regression.
EGFR are early involved in colorectal carcinogenesis, and their expression is strongly correlated to the neoplasia stage, leading to validate EGFR as an interesting surface biomarker of adenomas.
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•Physico-chemical and biological characterization of silicon carbide (SiC) powders.•SiC microparticles powders did not trigger a significant biological cytotoxicity.•SiC powders ...trigger variable pro-oxidative and pro-inflammatory responses.•Particle size and iron surface impurities influence SiC particles toxicity.•Surface oxidation state as a deep impact on oxidative stress and TNFα production.
Silicon carbide (SiC) an industrial-scale product manufactured through the Acheson process, is largely employed in various applications. Its toxicity has been poorly investigated. Our study aims at characterizing the physico-chemical features and the in vitro impact on biological activity of five manufactured SiC powders: two coarse powders (SiC C1/C2), two fine powders (SiC F1/F2) and a powder rich in iron impurities (SiC I). RAW 264.7 macrophages were exposed to the different SiC particles and the cellular responses were evaluated. Contrary to what happens with silica, no SiC cytotoxicity was observed but pro-oxidative and pro-inflammatory responses of variable intensity were evidenced. Oxidative stress (H2O2 production) appeared related to SiC particle size, while iron level regulated pro-inflammatory response (TNFα production). To investigate the impact of surface reactivity on the biological responses, coarse SiC C1 and fine SiC F1 powders were submitted to different thermal treatments (650–1400°C) in order to alter the oxidation state of the particle surface. At 1400°C a decrease in TNFα production and an increase in HO, COO− radicals production were observed in correlation with the formation of a surface layer of crystalline silica. Finally, a strong correlation was observed between surface oxidation state and in vitro toxicity.
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