Advanced search    

Search: authors:"Philip Demokritou"

11 papers found.
Use AND, OR, NOT, +word, -word, "long phrase", (parentheses) to fine-tune your search.

Protein corona: implications for nanoparticle interactions with pulmonary cells

We previously showed that cerium oxide (CeO2), barium sulfate (BaSO4) and zinc oxide (ZnO) nanoparticles (NPs) exhibited different lung toxicity and pulmonary clearance in rats. We hypothesize that these NPs acquire coronas with different protein compositions that may influence their clearance from the lungs. CeO2, silica-coated CeO2, BaSO4, and ZnO NPs were incubated in rat lung...

An integrated methodology for assessing the impact of food matrix and gastrointestinal effects on the biokinetics and cellular toxicity of ingested engineered nanomaterials

Engineered nanomaterials (ENMs) are increasingly added to foods to improve their quality, sensory appeal, safety and shelf-life. Human exposure to these ingested ENMs (iENMS) is inevitable, yet little is known of their hazards. To assess potential hazards, efficient in vitro methodologies are needed to evaluate particle biokinetics and toxicity. These methodologies must account...

Optimization of a nanotechnology based antimicrobial platform for food safety applications using Engineered Water Nanostructures (EWNS)

A chemical free, nanotechnology-based, antimicrobial platform using Engineered Water Nanostructures (EWNS) was recently developed. EWNS have high surface charge, are loaded with reactive oxygen species (ROS), and can interact-with, and inactivate an array of microorganisms, including foodborne pathogens. Here, it was demonstrated that their properties during synthesis can be fine...

Direct stimulation of human fibroblasts by nCeO 2 in vitro is attenuated with an amorphous silica coating

Background Nano-scaled cerium oxide (nCeO 2 ) is used in a variety of applications, including use as a fuel additive, catalyst, and polishing agent, yet potential adverse health effects associated with nCeO 2 exposure remain incompletely understood. Given the increasing utility and demand for engineered nanomaterials (ENMs) such as nCeO 2 , “safety-by-design” approaches are...

Advanced computational modeling for in vitro nanomaterial dosimetry

Background Accurate and meaningful dose metrics are a basic requirement for in vitro screening to assess potential health risks of engineered nanomaterials (ENMs). Correctly and consistently quantifying what cells “see,” during an in vitro exposure requires standardized preparation of stable ENM suspensions, accurate characterizatoin of agglomerate sizes and effective densities...

Silica coating influences the corona and biokinetics of cerium oxide nanoparticles

Background The physicochemical properties of nanoparticles (NPs) influence their biological outcomes. Methods We assessed the effects of an amorphous silica coating on the pharmacokinetics and pulmonary effects of CeO 2 NPs following intratracheal (IT) instillation, gavage and intravenous injection in rats. Uncoated and silica-coated CeO 2 NPs were generated by flame spray...

An integrated approach for the in vitro dosimetry of engineered nanomaterials

Background There is a great need for screening tools capable of rapidly assessing nanomaterial toxicity. One impediment to the development of reliable in vitro screening methods is the need for accurate measures of cellular dose. We present here a methodology that enables accurate determination of delivered to cell dose metrics. This methodology includes (1) standardization of...

Bioavailability, distribution and clearance of tracheally-instilled and gavaged uncoated or silica-coated zinc oxide nanoparticles

Murdaugh 0 Georgios A Sotiriou Thomas C Donaghey Philip Demokritou Joseph D Brain Ramon M Molina 0 Equal contributors Center for Nanotechnology and Nanotoxicology, Molecular and Integrative Physiological

Evaluation of cytotoxic, genotoxic and inflammatory responses of nanoparticles from photocopiers in three human cell lines

Background Photocopiers emit nanoparticles with complex chemical composition. Short-term exposures to modest nanoparticle concentrations triggered upper airway inflammation and oxidative stress in healthy human volunteers in a recent study. To further understand the toxicological properties of copier-emitted nanoparticles, we studied in-vitro their ability to induce cytotoxicity...

Residential exposure to motor vehicle emissions and the risk of wheezing among 7-8 year-old schoolchildren: a city-wide cross-sectional study in Nicosia, Cyprus

Background Several studies have reported associations between respiratory outcomes in children and a range of self-reported, administrative or geographical indicators of traffic pollution. First-time investigation into the frequency of asthmatic symptoms among 7-8 year-old Cypriot children in 1999-2000 showed increased prevalence in the capital Nicosia compared to other areas...

Prevalence and social environment of cigarette smoking in Cyprus youth

Philip Demokritou 1 2 Gregory N Connolly 4 0 The Biostatistics Center, The George Washington University , Rockville, MD , USA 1 Department of Environmental Health, Harvard School of Public Health , Boston