15 results match your criteria: "National Institute of Metrology Quality and Technology - INMETRO[Affiliation]"

Microfluidic-based skin-on-chip systems for safety assessment of nanomaterials.

Trends Biotechnol

October 2023

Nanosafety Group, International Iberian Nanotechnology Laboratory, Braga, Portugal. Electronic address:

The skin is the body's largest organ, continuously exposed to and affected by natural and anthropogenic nanomaterials (materials with external and internal dimensions in the nanoscale range). This broad spectrum of insults gives rise to irreversible health effects (from skin corrosion to cancer). Organ-on-chip systems can recapitulate skin physiology with high fidelity and potentially revolutionize the safety assessment of nanomaterials.

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Purpose: This study evaluated the effect of coating traditional and translucent Y-TZP with an industrial nanometric colloidal silica or glaze before or after sintering on the adhesion of zirconia with various ytrria concentration.

Materials And Methods: Specimens of Y-TZP with 3% and 5% yttria were subdivided into 5 groups (n=10), according to the coating applied and moment of application (before or after Y-TZP sintering): Control (no coating), Colloidal Silica/Sintering, Sintering/Colloidal Silica, Glaze/Sintering, Sintering/ Glaze. Lithium disilicate (LD) was used as positive control.

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Hierarchical Porous Carbon-PtPd Catalysts and Their Activity toward Oxygen Reduction Reaction.

ACS Omega

June 2022

Laboratorio de Investigación de Electroquímica Aplicada, Facultad de Ciencias, Universidad Nacional de Ingeniería, Av. Túpac Amaru 210, Rímac, Lima 15333, Perú.

PtPd bimetallic catalysts supported on hierarchical porous carbon (HPC) with different porous sizes were developed for the oxygen reduction reaction (ORR) toward fuel cell applications. The HPC pore size was controlled by using SiO nanoparticles as a template with different sizes, 287, 371, and 425 nm, to obtain three HPC materials denoted as HPC-1, HPC-2, and HPC-3, respectively. PtPd/HPC catalysts were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy.

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Morphological and biochemical repercussions of infection in a 3D human brain neurospheres model.

Brain Behav Immun Health

February 2021

Institute of Biophysics Carlos Chagas Filho and National Center for Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, RJ, Brazil.

Background: Toxoplasmosis is caused by the parasite that can infect the central nervous system (CNS), promoting neuroinflammation, neuronal loss, neurotransmitter imbalance and behavioral alterations. infection is also related to neuropsychiatric disorders such as schizophrenia. The pathogenicity and inflammatory response in rodents are different to the case of humans, compromising the correlation between the behavioral alterations and physiological modifications observed in the disease.

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Background: Coronavirus disease 2019 (COVID-19) can progress to severe pneumonia with respiratory failure and is aggravated by the deregulation of the immune system causing an excessive inflammation including the cytokine storm.

Methods: In this study, we report that severe acutely infected patients have high levels of both type-1 and type-2 cytokines.

Results: Our results show abnormal cytokine levels upon T-cell stimulation, in a nonpolarized profile.

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Corn starch films as a long-term drug delivery system for chlorhexidine gluconate.

Mater Sci Eng C Mater Biol Appl

July 2020

PEMM/COPPE, Federal University of Rio de Janeiro, Department of Materials Science and Engineering, P.O. Box 68505, 21945-970 Rio de Janeiro, RJ, Brazil; PENT/COPPE, Federal University of Rio de Janeiro, P.O. Box 68505, 21945-970 Rio de Janeiro, RJ, Brazil. Electronic address:

The present study describes the development of a chlorhexidine long-term drug delivery system using starch as a biodegradable polymer base. Three batches of thermoplastic starch films, containing starch particles/nanoparticles and chlorhexidine (CHX), were manufactured by casting. Morphological characterization showed an irregular surface with particles incorporated with chlorhexidine agglomerated in a starch matrix.

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Purpose: In chronic kidney disease (CKD) patients, dysbiosis is associated with inflammation and cardiovascular risk, so many nutritional strategies are being studied to reduce these complications. Resistant starch (RS) can be considered a prebiotic that promotes many benefits, including modulation of gut microbiota which is linked to immune-modulatory effects. The aim of this study was to evaluate the effects of RS supplementation on proinflammatory cytokines in CKD patients on hemodialysis (HD).

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Background: The blood brain barrier (BBB) is the bottleneck of brain-targeted drug development. Due to their physico-chemical properties, nanoparticles (NP) can cross the BBB and accumulate in different areas of the central nervous system (CNS), thus are potential tools to carry drugs and treat brain disorders. In vitro systems and animal models have demonstrated that some NP types promote neurotoxic effects such as neuroinflammation and neurodegeneration in the CNS.

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Advances and potential application of gold nanoparticles in nanomedicine.

J Cell Biochem

October 2019

Laboratory of Bioengineering and in Vitro Toxicology, Directory of Metrology Applied to Life Sciences - Dimav, National Institute of Metrology Quality and Technology - INMETRO, Duque de Caxias, RJ, Brazil.

Nanomedicine is an emerging research area which has brought new possibilities and promising applications in image, diagnosis, and treatment. Nanoparticles (NPs) for medicinal purposes can be made of several material types such as silica, carbon, different polymers, and metals as silver, copper, titanium, and gold. Gold NPs (AuNPs) are the most studied and used, mostly due to their characteristics including simple preparation, controllable size and distribution, biocompatibility, good acceptance of surface modifications, and specific surface plasmon resonance (SPR).

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The resonant wave modes in monomodal and multimodal planar Surface Plasmon Resonance (SPR) sensors and their response to a bidimensional array of gold nanoparticles (AuNPs) are analyzed both theoretically and experimentally, to investigate the parameters that rule the correct nanoparticle counting in the emerging metal nanoparticle-amplified surface plasmon resonance (PA-SPR) spectroscopy. With numerical simulations based on the Finite Element Method (FEM), we evaluate the error performed in the determination of the surface density of nanoparticles when the Maxwell-Garnett effective medium theory is used for fast data processing of the SPR reflectivity curves upon nanoparticle detection. The deviation increases directly with the manifestations of non-negligible scattering cross-section of the single nanoparticle, dipole-dipole interactions between adjacent AuNPs and dipolar interactions with the metal substrate.

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Nano hydroxyapatite-blasted titanium surface affects pre-osteoblast morphology by modulating critical intracellular pathways.

Biotechnol Bioeng

August 2017

Department of Chemistry and Biochemistry, Bioscience Institute, State University of São Paulo-UNESP, P.O. Box: 510, 18618-970, Rubião Jr, campus Botucatu, São Paulo, Botucatu, Brazil.

Although, intracellular signaling pathways are proposed to predict the quality of cell-surface relationship, this study addressed pre-osteoblast behavior in response to nano hydroxyapatite (HA)-blasted titanium (Ti) surface by exploring critical intracellular pathways and pre-osteoblast morphological change. Physicochemical properties were evaluated by atomic force microscopy (AFM) and wettability considering water contact angle of three differently texturized Ti surfaces: Machined (Mac), Dual acid-etching (DAE), and nano hydroxyapatite-blasted (nHA). The results revealed critical differences in surface topography, impacting the water contact angle and later the osteoblast performance.

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Background: Poly-lactic acid nanoparticles (PLA-NP) are a type of polymeric NP, frequently used as nanomedicines, which have advantages over metallic NP such as the ability to maintain therapeutic drug levels for sustained periods of time. Despite PLA-NP being considered biocompatible, data concerning alterations in cellular physiology are scarce.

Methods: We conducted an extensive evaluation of PLA-NP biocompatibility in human lung epithelial A549 cells using high throughput screening and more complex methodologies.

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In the current paper, a new strategy for risk assessment of nanomaterials is described, which builds upon previous project outcomes and is developed within the FP7 NANoREG project. NANoREG has the aim to develop, for the long term, new testing strategies adapted to a high number of nanomaterials where many factors can affect their environmental and health impact. In the proposed risk assessment strategy, approaches for (Quantitative) Structure Activity Relationships ((Q)SARs), grouping and read-across are integrated and expanded to guide the user how to prioritise those nanomaterial applications that may lead to high risks for human health.

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The Involvement of Parasympathetic and Sympathetic Nerve in the Inflammatory Reflex.

J Cell Physiol

September 2016

Laboratory of Bioengineering and in Vitro Toxicology, Directory of Metrology Applied to Life Sciences (LABET)-Dimav, National Institute of Metrology Quality and Technology-INMETRO, Duque de Caxias, Rio de Janeiro, Brazil.

Production of inflammatory cytokines plays important roles in the response against tissue injury and in host defense. Alterations in the production of inflammatory cytokines may cause local or systemic inflammatory imbalance, culminating in organ failure or lethal systemic inflammation. The cholinergic anti-inflammatory pathway has been implicated as an important mechanism to regulate inflammation of targeted tissue.

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Hazard effects of nanoparticles in central nervous system: Searching for biocompatible nanomaterials for drug delivery.

Toxicol In Vitro

October 2015

Laboratory of Bioengineering and in Vitro Toxicology, Directory of Metrology Applied to Life Sciences - DIMAV, National Institute of Metrology Quality and Technology - INMETRO, 25250-020 Duque de Caxias, RJ, Brazil; Dental School, Fluminense Federal University, 24020-140 Niteroi, RJ, Brazil.

Nanostructured materials are widely used in many applications of industry and biomedical fields. Nanoparticles emerges as potential pharmacological carriers that can be applied in the regenerative medicine, diagnosis and drug delivery. Different types of nanoparticles exhibit ability to cross the brain blood barrier (BBB) and accumulate in several brain areas.

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