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1.
Chemosphere ; 246: 125765, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31927370

RESUMO

A surfactant assisted extraction (SAE) method was developed to extract incidental nanoparticles (INPs) in the <300 nm particle size fraction from road runoff sediments and applied to a road runoff sediment. The method was evaluated by spiking experiments of road runoff sediment with engineered nanoparticle (ENP) suspensions of gold (Au-ENPs) between 30 nm and 200 nm and platinum (Pt-ENPs) between 30 nm and 70 nm with content ranging from 40 to 800 ng/g. Suspensions were analyzed by single particle (sp-)ICP-MS. In the presence of a road runoff matrix, an increase in ENP sizes by a maximum of 8% for Au-ENPs and 9% for Pt-ENPs was observed. ENPs mass recovery was >50% for all Au-ENPs with content higher than 200 ng/g and for 30 and 50 nm Pt-ENPs at content of 160 ng/g while for lower content the recovery was 0%. For 70 nm Pt-ENPs, recovery was always >80% and increased with increasing Pt content up to 100% in the presence of road runoff matrix. Metal content of INPs in the road runoff sediment in the fraction <300 nm decreased from copper (Cu; µg/g)> zinc (Zn)> zirconium (Zr)> cerium (Ce)> lead (Pb)> cadmium (Cd) > platinum (Pt; µg/g). Over 90% of Pt-, Zn-, Cd-, Pb- and Ce-INPs are composed of particles with less than 20 fg, while Zr- and Cu-INPs are dominated by masses higher than 20 fg. The tested SAE may be applicable to determine environmental contents of INPs in sediments and possibly in soils.


Assuntos
Monitoramento Ambiental , Nanopartículas/química , Poluentes Químicos da Água/química , Cobre , Ouro , Nanopartículas/análise , Tamanho da Partícula , Platina , Surfactantes Pulmonares , Solo , Tensoativos , Poluentes Químicos da Água/análise , Zinco
2.
Artigo em Inglês | MEDLINE | ID: mdl-31596687

RESUMO

This paper identifies knowledge gaps on the sustainability and impacts of plastics and presents some recommendations from an expert group that met at a special seminar organised by the European Commission at the end of 2018. The benefits of plastics in society are unquestionable, but there is an urgent need to better manage their value chain. The recently adopted European Strategy for Plastics stressed the need to tackle the challenges related to plastics with a focus on plastic litter including microplastics. Microplastics have been detected mainly in the marine environment, but also in freshwater, soil and air. Based on today's knowledge they may also be present in food products. Although nanoplastics have not yet been detected, it can be assumed that they are also present in the environment. This emerging issue presents challenges to better understand future research needs and the appropriate immediate actions to be taken to support the necessary societal and policy initiatives. It has become increasingly apparent that a broad and systematic approach is required to achieve sustainable actions and solutions along the entire supply chain. It is recognised that there is a pressing need for the monitoring of the environment and food globally. However, despite the number of research projects increasing, there is still a lack of suitable and validated analytical methods for detection and quantification of micro- and nanoplastics. There is also a lack of hazard and fate data which would allow for their risk assessment. Some priorities are identified in this paper to bridge the knowledge gaps for appropriate management of these challenges. At the same time it is acknowledged that there is a great complexity in the challenges that need to be tackled before a really comprehensive environmental assessment of plastics, covering their entire life cycle, will be possible.


Assuntos
Contaminação de Alimentos/análise , Nanopartículas/análise , Plásticos/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Análise de Alimentos
3.
Biomed Chromatogr ; 34(1): e4703, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31629393

RESUMO

Ibrutinib has an excellent effect in the treatment of mantle cell lymphoma so it has attracted much attention. A novel ibrutinib nanocrystalline was exploited in our study to improve the bioavailability. A fast and reliable UPLC-MS/MS method was established for the accurate quantification of ibrutinib in rat plasma. The chromatographic separation was achieved by an Agilent zorbax SB-C18 rapid solution HD column (2.1 × 50 mm, 1.8 µm). The mobile phase consisted of deionized water (containing 10 mm ammonium acetate and 0.1% formic acid) and pure acetonitrile. Isocratic elution (water-acetonitrile 10:90, v/v) was adopted and the flow rate was 0.4 mL/min. Column temperature was set to 40°C. Vilazodone was used as the internal standard in this analytical method. Multiple reaction monitoring mode with positive electrospray ionization was selected to detect ibrutinib and vilazodone. Acetonitrile was used to precipitate protein to extract plasma samples. There was no endogenous interference for both ibrutinib and vilazodone and the linear range of this method was 1-2000 ng/mL. The recoveries were 98.4, 97.4 and 102.7% at low, medium and high concentrations. Accordingly, the matrix effect was 96.6, 111.1 and 99.6%. The pharmacokinetic difference between ibrutinib crude and a novel ibrutinib nanocrystalline in rats was investigated by this validated method successfully. The peak concentration and area under the concentration-time curve showed significant differences in gender and the bioavailability was improved after oral administration of ibrutinib nanocrystalline.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Nanopartículas/análise , Pirazóis/sangue , Pirimidinas/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Disponibilidade Biológica , Feminino , Limite de Detecção , Modelos Lineares , Masculino , Nanopartículas/química , Nanopartículas/metabolismo , Pirazóis/química , Pirazóis/farmacocinética , Pirimidinas/química , Pirimidinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes
4.
J Agric Food Chem ; 68(1): 67-76, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31710472

RESUMO

Nanoparticles (NPs) are known to significantly alter plant metabolism in a dose-dependent manner, with effects ranging from stimulation to toxicity. The metabolic adjustment and ionomic balance of bean (Phaseolus vulgaris L.) roots and leaves gained from plants grown in a solid medium added with relatively low dosages (0, 25, 50, and 100 mg/L) of CeO2 NPs were investigated. Ce accumulated in the roots (up to 287.91 mg/kg dry weight) and translocated to the aerial parts (up to 2.78% at the highest CeO2 dosage), and ionomic analysis showed that CeO2 NPs interfered with potassium, molybdenum, and zinc. Unsupervised hierarchical clustering analysis from metabolomic profiles suggested a dose-dependent and tissue-specific metabolic reprogramming induced by NPs. The majority of differential metabolites belonged to flavonoids and other phenolics, nitrogen-containing low molecules (such as alkaloids and glucosinolates), lipids, and amino acids.


Assuntos
Cério/farmacologia , Phaseolus/efeitos dos fármacos , Metabolismo Secundário/efeitos dos fármacos , Aminoácidos/análise , Aminoácidos/metabolismo , Cério/análise , Flavonoides/análise , Flavonoides/metabolismo , Nanopartículas/análise , Phaseolus/química , Phaseolus/metabolismo , Fenóis/análise , Fenóis/metabolismo , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo
5.
Chemosphere ; 239: 124776, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31526988

RESUMO

Modern microscopy studies are capable of revealing ultra-fine particles (UFPs) and nanoparticles (NPs) that are produced in the processes related to traffic vehicular, industrial, metropolitan, and marine aerosol dry deposition in the coastal zones. Especially, secondary aerosol passages complexes categories of NPs and UFPs, which can be accumulated on construction compounds and by dry deposition, encourages multiples monuments deterioration routes. The advanced electron microscopies method is one of the most utilized in environmental studies. Between the different industrial areas in the world, the Caribbean area is the most relevant symbols of air quality due to climatic conditions with strong winds, but this study shows that regionally the most industrialized region does not have an adequate air quality. In the present work, electron microscopy analyses are used to describe of the extent of ultra-fine particle and nanoparticles in walls in contact to weathering. Numerous phases were recognized by advanced mineralogy methods. Thanks to the new analytical procedure it was feasible to understand NPs and UFPs; the occurrence of potential hazardous elements (PHEs), most of them as minerals but also combined in multiple accumulations with Al-Cr-Fe-K-Mg-Pb-Si-Ti-Zn amorphous; and carbonaceous phases.


Assuntos
Poluentes Atmosféricos/análise , Nanopartículas/análise , Material Particulado/análise , Aerossóis/análise , Poluentes Atmosféricos/química , Poluição do Ar/análise , Atmosfera , Região do Caribe , Colômbia , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Desenvolvimento Industrial , Minerais/análise , Veículos Automotores , Material Particulado/química , Vento
6.
Ecotoxicol Environ Saf ; 187: 109845, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31654865

RESUMO

The extensive use of nano-fabricated products in daily life is releasing a large volume of engineered nanoparticles (ENPs) in the environment having unknown consequences. Meanwhile, little efforts have been paid to immobilize and prevent the entry of these emerging contaminants in the food chain through plant uptake. Herein, we investigated the biochar role in cerium oxide nanoparticles (CeO2NPs) bioaccumulation and subsequent translocation in wheat (Triticum aestivum L.) as well as impact on growth, photosynthesis and gas-exchange related physiological parameters. Results indicated that CeO2NPs up to 500 mg L-1 level promoted the plant growth by triggering photosynthesis, transpiration and stomatal conductance. Higher NPs concentration (2000 mg CeO2NPs L-1) has negatively affected the plant growth and photosynthesis related processes. Conversely, biochar amendment with CeO2NPs considerably reduced (~9 folds) the plants accumulated contents of Ce even at 2000 mg L-1 exposure level of CeO2NPs through surface complexation process and alleviated the phyto-toxic effects of NPs on plant growth. XPS and FTIR analysis confirmed the role of biochar-mediated carboxylate and hydroxyl groups bonding with CeO2NPs. These findings provides an inside mechanistic understanding about biochar interaction with nano-pollutants to inhibit their bioavailability to plant body.


Assuntos
Cério/análise , Carvão Vegetal/química , Nanopartículas/análise , Fotossíntese/efeitos dos fármacos , Poluentes do Solo/análise , Triticum/efeitos dos fármacos , Disponibilidade Biológica , Cério/metabolismo , Recuperação e Remediação Ambiental/métodos , Nanopartículas/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Triticum/metabolismo
7.
Sci Total Environ ; 692: 1116-1124, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539943

RESUMO

Bacterial biofilms are structured cell communities embedded in a matrix of extracellular polymeric substances (EPS) and a ubiquitous growth form of bacteria in the environment. A wide range of interactions between biofilms and nanoparticles have been reported. In the present study, the influence of a mixed bacterial biofilm on retention of biogenic selenium nanoparticles (BioSeNPs) and consequences for immobilization of elemental mercury (Hg0) in a porous quartz sand system were examined. BioSeNPs were significantly retained in the presence of a biofilm through electrical double layer effects, hydrogen bonding, and hydrophobic, steric and bridging interactions. Moreover, enhanced surface roughness, pore clogging, sieving and entrapment effects mediated by the biofilm also contributed to deposition of BioSeNPs. Whereas, thiol groups associated with the biofilm is a little helpful for the capture of Hg0. It is proposed that oxidative complexation between Hg0 and thiol compounds or S containing organic matter in the biofilm may result in the formation of Hg2+-thiolate complexes and HgS during the binding of Hg0 with BioSeNPs. The formation of mercury selenide was also involved in Hg0 immobilization in the porous quartz sand system.


Assuntos
Mercúrio/análise , Modelos Químicos , Nanopartículas/análise , Selênio/análise , Biofilmes , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas/química , Quartzo , Selênio/química
8.
Environ Pollut ; 255(Pt 1): 113177, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31521995

RESUMO

The transport and retention of nanoplastics (NP, 200 nm nanopolystyrene) functionalized with surface carboxyl (NPC), sulfonic (NPS), low-density amino (negatively charged, NPA-), and high-density amino (positively charged, NPA+) groups in seawater-saturated sand with/without humic acid were examined to explore the role of NP surface functionalities. The mass percentages of NP recovered from the effluent (Meff) with a salinity of 35 practical salinity units (PSU) were ranked as follows: NPC (19.69%) > NPS (16.37%) > NPA+ (13.33%) > NPA- (9.78%). The homoaggregation of NPS and NPA- was observed in seawater. The transport of NPA- exhibited a ripening phenomenon (i.e., a decrease in the transport rate with time) due to the high attraction of NP with previously deposited NP, whereas monodispersed NPA+ presented a low Meff value because of the electrostatic attraction between NPA+ and negatively charged sand. Retention experiments showed that the majority of NPC, NPS and NPA+ accumulated in a monolayer on the sand surface, whereas NPA- accumulated in multiple layers. Suwannee River humic acid (SRHA) could remarkably improve the transportability of NPC, NPS, and NPA- by increasing steric repulsion. The strong attraction between NPA+ and the deposited NPA+ in the presence of SRHA triggered the weak ripening phenomenon. As seawater salinity decreased from 35 PSU to 3.5 PSU, the increase in electrostatic repulsion of NP-NP and NP-sand enhanced the transport of NPC, NPS, and NPA-, and the ripening of NPA- breakthrough curves disappeared. In deionized water, NPC, NPS, and NPA- achieved complete column breakthrough because the electrostatic repulsion between NP and sand intensified. However, the Meff values of NPA+ in 3.5 PSU seawater and deionized water presented limited increments of 15.49% and 23.67%, respectively. These results indicated that the fate of NP in sandy marine environments were strongly affected by NP surface functionalities, seawater salinity, and coexisting SRHA.


Assuntos
/análise , 24975/química , Água do Mar/química , Poluentes Químicos da Água/análise , Substâncias Húmicas/análise , Nanopartículas/análise , Poliestirenos/análise , Salinidade , Dióxido de Silício/química , Eletricidade Estática , Água/química
9.
Bioconjug Chem ; 30(7): 1923-1937, 2019 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-31259537

RESUMO

The formation of a protein corona has been considered a pitfall in the clinical translation of nanomedicines. Hence, interdisciplinary studies on corona characterization are critically essential. A deep understanding of the formation of hard and soft protein coronas upon in vivo administration of nanoparticles is vital. The protein corona gives the nanoplatform a new biological identity. Furthermore, the control of and mechanistic understanding of corona formation as it is regulated by the physicochemical properties of nanoparticles is crucial for developing safe nanomedicines. A growing number of analytical techniques have been developed in the past decade for examining NP-protein interactions, contributing to a better understanding of protein corona formation on the surface of nanoparticles. In this Review, we summarize the latest developments in the in vivo and in vitro study of dynamic protein corona formation. Insights derived from techniques used to visualize, quantify, and define protein coronas, as well as the methods for examining the kinetics and structural changes of coronal proteins, are discussed. The potential challenges and future perspectives in the study of protein corona formation and its effects on biological behavior and applications of therapeutic nanomaterials are also provided.


Assuntos
Nanopartículas/metabolismo , Coroa de Proteína/metabolismo , Adsorção , Animais , Humanos , Microscopia de Força Atômica , Modelos Moleculares , Nanopartículas/análise , Nanopartículas/ultraestrutura , Ligação Proteica , Coroa de Proteína/análise
10.
Part Fibre Toxicol ; 16(1): 31, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-31319864

RESUMO

BACKGROUND: Titanium dioxide (TiO2) nanoparticles are among the most manufactured nanomaterials in the industry, and are used in food products, toothpastes, cosmetics and paints. Pregnant women as well as their conceptuses may be exposed to TiO2 nanoparticles; however, the potential effects of these nanoparticles during pregnancy are controversial, and their internal distribution has not been investigated. Therefore, in this study, we investigated the potential effects of oral exposure to TiO2 nanoparticles and their distribution during pregnancy. TiO2 nanoparticles were orally administered to pregnant Sprague-Dawley rats (12 females per group) from gestation days (GDs) 6 to 19 at dosage levels of 0, 100, 300 and 1000 mg/kg/day, and then cesarean sections were conducted on GD 20. RESULTS: In the maternal and embryo-fetal examinations, there were no marked toxicities in terms of general clinical signs, body weight, food consumption, organ weights, macroscopic findings, cesarean section parameters and fetal morphological examinations. In the distribution analysis, titanium contents were increased in the maternal liver, maternal brain and placenta after exposure to high doses of TiO2 nanoparticles. CONCLUSION: Oral exposure to TiO2 during pregnancy increased the titanium concentrations in the maternal liver, maternal brain and placenta, but these levels did not induce marked toxicities in maternal animals or affect embryo-fetal development. These results could be used to evaluate the human risk assessment of TiO2 nanoparticle oral exposure during pregnancy, and additional comprehensive toxicity studies are deemed necessary considering the possibility of complex exposure scenarios and the various sizes of TiO2 nanoparticles.


Assuntos
Encéfalo/metabolismo , Fígado/metabolismo , Nanopartículas/análise , Placenta/metabolismo , Titânio/farmacocinética , Administração Oral , Animais , Relação Dose-Resposta a Droga , Feminino , Exposição Materna , Nanopartículas/química , Especificidade de Órgãos , Gravidez , Ratos , Distribuição Tecidual , Titânio/química
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 223: 117333, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31280125

RESUMO

Ag+ and SCN- play extremely important roles in the fields of the physiology and environment. In this work, on the basis of phenanthro[9,10-d]imidazole derivative (DIPIP) which can exhibit the aggregation-induced emission (AIE) properties in aqueous solution, we achieved a sequential on-off-on switch for Ag+ and SCN- with high selectivity and sensitivity. A remarkable fluorescence quenching effect of Ag+ on the probe DIPIP was observed with 1:2 stoichiometry, Subsequently, the fluorescence intensity of in situ generated DIPIP-Ag+ ensemble was easily switched on after the interaction between Ag+ and SCN-, which was attributed to the stronger affinity of SCN- to capture Ag+. In particular, the extreme limits of detection (LOD) for Ag+ and SCN- in standard solutions were as low as to be 74.5 nM and 7.8 nM, respectively. Furthermore, the probe DIPIP and the DIPIP-Ag+ ensemble could be used to detect Ag+ in the real water and SCN- in smoker saliva samples, respectively. In addition, the sequential "on-off-on" fluorescence mode of DIPIP to Ag+ and SCN- were also successfully applied in living HeLa cells.


Assuntos
Corantes Fluorescentes/química , Imidazóis/química , Nanopartículas/análise , Fenantrenos/química , Saliva/química , Prata/análise , Água/química , Sobrevivência Celular , Células HeLa , Humanos , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Fluorescência , Tiocianatos
12.
Artigo em Inglês | MEDLINE | ID: mdl-31284093

RESUMO

Engineered nanoparticles such as iron oxide (Fe3O4) nanoparticles (IONPs) offer several benefits in nanomedicine, notably as contrast agents in magnetic resonance imaging (MRI). Ferumoxytol, a suspension of IONPs (with a manufacturer's reported particle diameter of 27 nm-30 nm) was characterized as a standard by spiking into rat blood plasma and cell fractions. Nanoparticle separation, and characterisation was investigated with asymmetric flow field-flow fractionation (AF4) coupled online to ultraviolet-visible spectroscopy (UV-VIS), multi-angle light scattering (MALS) and inductively coupled plasma mass spectrometry (ICP-MS) detectors; also with single particle inductively coupled plasma mass spectrometry (spICP-MS) and transmission electron microscopy (TEM). MALS signal of pristine Ferumoxytol indicated radii of gyration (Rg) between 15 and 28 nm for the Fe-containing fraction and 30-75 nm for the non-Fe fraction. IONPs spiked into blood plasma indicated a polydisperse distribution between 40 nm - 120 nm suggesting matrix-induced size alterations. Spiking of the IONPs into cells showed a shift in ICP-MS Fe signal to 15 min, however the MALS signal was undetected within the Fe containing fraction of the IONPs suggesting NP loss due to membrane-particle attraction. spICP-MS analysis of IONPs spiked in rat plasma suggested the release of Fe-containing colloids into plasma causing an increase in diameter of IONPs to 52 ±â€¯0.8 nm; whereas no major variation in particle size and distribution of the IONPs spiked in cell fractions was observed (33.2 ±â€¯2.0 nm) suggesting non-alteration of the NP Fe core. A complementary application of microscopic, light scattering, and mass spectrometry techniques for the characterisation of NPs in challenging biological matrices like blood has been demonstrated.


Assuntos
Células Sanguíneas/química , Óxido Ferroso-Férrico/sangue , Fracionamento por Campo e Fluxo/métodos , Nanopartículas/análise , Espectrometria de Massas em Tandem/métodos , Animais , Espectrometria de Massas , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Plasma/química , Ratos
13.
Biosensors (Basel) ; 9(2)2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31163706

RESUMO

Solution-phase and intracellular biosensing has substantially enhanced our understanding of molecular processes foundational to biology and pathology. Optical methods are favored because of the low cost of probes and instrumentation. While chromatographic methods are helpful, fluorescent biosensing further increases sensitivity and can be more effective in complex media. Resonance energy transfer (RET)-based sensors have been developed to use fluorescence, bioluminescence, or chemiluminescence (FRET, BRET, or CRET, respectively) as an energy donor, yielding changes in emission spectra, lifetime, or intensity in response to a molecular or environmental change. These methods hold great promise for expanding our understanding of molecular processes not just in solution and in vitro studies, but also in vivo, generating information about complex activities in a natural, organismal setting. In this review, we focus on dyes, fluorescent proteins, and nanoparticles used as energy transfer-based optical transducers in vivo in mice; there are examples of optical sensing using FRET, BRET, and in this mammalian model system. After a description of the energy transfer mechanisms and their contribution to in vivo imaging, we give a short perspective of RET-based in vivo sensors and the importance of imaging in the infrared for reduced tissue autofluorescence and improved sensitivity.


Assuntos
Técnicas Biossensoriais/métodos , Transferência Ressonante de Energia de Fluorescência/métodos , Medições Luminescentes/métodos , Animais , Corantes Fluorescentes/análise , Humanos , Proteínas Luminescentes/análise , Modelos Moleculares , Nanopartículas/análise , Imagem Óptica/métodos
14.
Inhal Toxicol ; 31(3): 125-130, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-31179784

RESUMO

Objectives: The objective of this study was the evaluation of the professional exposure to nanoparticles during tasks performed in workstations for production of metallic parts by laser welding additive manufacturing. Materials and methods: The study was developed in an installed additive manufacturing machine, having controlled temperature and humidity in an industrial unit where metal parts were being produced using stainless steel powders of granulometry of 10 to 35 µm. Results and discussion: Monitoring of airborne nanoparticles emission was made using adequate equipment, which showed considerable number of nanoparticles over the baseline, having the same composition as the steel powder used. Conclusion: It is concluded that the values of professional exposure to nanoparticles are high in these workstations and that the nanoparticles to which the workers are exposed are small in size (around 15 nm), thus having a strong capacity for alveolar penetration and, consequently, with a strong possibility of passing to the bloodstream, accumulating in the body.


Assuntos
Poluentes Ocupacionais do Ar/análise , Nanopartículas/análise , Exposição Ocupacional/análise , Aço Inoxidável , Soldagem , Monitoramento Ambiental , Humanos , Pós
15.
Environ Pollut ; 252(Pt A): 511-521, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31167159

RESUMO

Nanoplastics have attracted increasing attention in recent years due to their widespread existence in the environment and the potential adverse effects on living organisms. In this paper, the toxic effects of nanoplastics on organisms were systematically reviewed. The translocation and absorption of nanoplastics, as well as the release of additives and contaminants adsorbed on nanoplastics in the organism body were discussed, and the potential adverse effects of nanoplastics on human health were evaluated. Nanoplastics can be ingested by organisms, be accumulated in their body and be transferred along the food chains. Nanoplastics showed effects on the growth, development and reproduction of organisms, and disturbing the normal metabolism. The toxic effects on living organisms mainly depended on the surface chemical properties and the particle size of nanoplastics. Positively charged nanoplastics showed more significant effects on the normal physiological activity of cells than negatively charged nanoplastics, and smaller particle sized nanoplastics could more easily penetrate the cell membranes, hence, accumulated in tissues and cells. Additionally, the release of additives and contaminants adsorbed on nanoplastics in organism body poses more significant threats to organisms than nanoplastics themselves. However, there are still knowledge gaps in the determination and quantification of nanoplastics, as well as their contaminant release mechanisms, degradation rates and process from large plastics to nanoplastics, and the transportation of nanoplastics along food chains. These challenges would hinder the risk assessment of nanoplastics in the environment. It is necessary to further develop the risk assessment of nanoplastics and deeply investigate its toxicological effects.


Assuntos
Bivalves/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Nanopartículas/toxicidade , Nematoides/efeitos dos fármacos , Plásticos/toxicidade , Animais , Cadeia Alimentar , Humanos , Nanopartículas/análise , Tamanho da Partícula , Plásticos/análise , Propriedades de Superfície
16.
Nat Protoc ; 14(7): 2015-2035, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31168087

RESUMO

Measurements of a single entity underpin knowledge of the heterogeneity and stochastics in the behavior of molecules, nanoparticles, and cells. Electrochemistry provides a direct and fast method to analyze single entities as it probes electron/charge-transfer processes. However, a highly reproducible electrochemical-sensing nanointerface is often hard to fabricate because of a lack of control of the fabrication processes at the nanoscale. In comparison with conventional micro/nanoelectrodes with a metal wire inside, we present a general and easily implemented protocol that describes how to fabricate and use a wireless nanopore electrode (WNE). Nanoscale metal deposition occurs at the tip of the nanopipette, providing an electroactive sensing interface. The WNEs utilize a dynamic ionic flow instead of a metal wire to sense the interfacial redox process. WNEs provide a highly controllable interface with a 30- to 200-nm diameter. This protocol presents the construction and characterization of two types of WNEs-the open-type WNE and closed-type WNE-which can be used to achieve reproducible electrochemical measurements of single entities. Combined with the related signal amplification mechanisms, we also describe how WNEs can be used to detect single redox molecules/ions, analyze the metabolism of single cells, and discriminate single nanoparticles in a mixture. This protocol is broadly applicable to studies of living cells, nanomaterials, and sensors at the single-entity level. The total time required to complete the protocol is ~10-18 h. Each WNE costs ~$1-$3.


Assuntos
Técnicas Eletroquímicas/instrumentação , Eletrodos , Nanoporos , Nanotecnologia/métodos , Técnicas Eletroquímicas/métodos , Desenho de Equipamento , Humanos , Células MCF-7 , Nanopartículas/análise , Oxirredução , Técnicas de Patch-Clamp/instrumentação , Técnicas de Patch-Clamp/métodos , Análise de Célula Única/instrumentação , Análise de Célula Única/métodos , Tecnologia sem Fio
17.
Int J Pharm ; 566: 680-686, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31176851

RESUMO

Liposomes are potent adjuvant constituents for licensed vaccines and vaccine candidates and carriers for drug delivery. Depending on the method of preparation, liposomes vary in size distribution, either forming uniform small size vesicles or a heterogeneous mixture of small to large vesicles. Importantly, differences in liposomal size have been demonstrated to induce differential immune responses. Determination of particle size distribution could therefore be crucial for the efficacy and stability of vaccine formulations. We compared the techniques of dynamic light scattering, laser diffraction, and conventional nanoparticle tracking analysis with a novel multispectral advanced nanoparticle tracking analysis (MANTA) for particle size determination of mono- and polydisperse liposomes. MANTA reported an average 146 nm size of monodisperse liposomes but showed a multimodal distribution of polydisperse liposomes with continuous sizes from 50 to 2000 nm. However, approximately 95% of particles were in the size range of 50-1500 nm and only few particles were identified in the 1500-2000 nm range for the investigated volume. Based on our results, we conclude that MANTA is the most suitable approach and can serve as stand-alone technique for particle size characterization of heterogeneous liposome samples in the 50-2000 nm size range.


Assuntos
Nanopartículas/análise , Difusão Dinâmica da Luz , Lipossomos , Tamanho da Partícula
18.
Talanta ; 202: 251-258, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171178

RESUMO

The quantitative uptake of Silica nanoparticles (SiNPs), although representing an essential prerequisite for their theranostic use, is difficult to address and it is still not utterly investigated. In this study, we tested the uptake and toxicity of two different types of luminescent core-shell silica-PEG (polyethylene glycol) nanoparticles SiNP and their carboxylate analogues on human adenocarcinoma cell line LoVo. We assessed the intracellular spatial distribution and concentration of Si element in the cell by a state-of-the-art approach merging synchrotron-based X-ray techniques (XRFM) with scanning transmission X-Ray microscopy (STXM). The concentration maps of Si obtained reflect the distribution of the SiNPs. In addition, we calculated the number of SiNPs per volume unit in each single cell, quantitating the exact amount of conveyed particles. The absence of effects on proliferation and cell death was confirmed by viability assays, morphological analysis and cytofluorimetric evaluation of ROS content. The three-dimensional analysis of intracellular uptake of both types of nanoparticles (with different surface charge) was performed by confocal fluorescence microscopy, which showed a main localization in the cytosolic region with no sign of nuclear uptake.


Assuntos
Neoplasias do Colo/química , Nanopartículas/análise , Dióxido de Silício/análise , Síncrotrons , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/patologia , Humanos , Microscopia de Fluorescência , Dióxido de Silício/síntese química , Dióxido de Silício/farmacologia , Espectrometria por Raios X , Células Tumorais Cultivadas , Raios X
19.
Environ Sci Pollut Res Int ; 26(24): 24922-24932, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31243660

RESUMO

The effects of low-molecular-weight organic acids (LMWOAs) on the transport of graphene oxide nanoparticles in saturated kaolinite- and goethite-coated sand columns were studied. Acetic acid, glycolic acid, malonic acid, and tartaric acid were chosen in the experiments. LMWOAs enhanced the mobility of GO by electrostatic/steric repulsion. In addition, they competed with GO for limited deposition sites on grain surfaces. The effects of organic acids on the transport of GO strongly depended on organic acid species. In general, the transport enhancement effects followed the order of tartaric acid > malonic acid > glycolic acid > acetic acid; this difference may be related to the number and type of functional groups of organic acids. Different LMWOAs enhanced the transport of GO in goethite-coated sand to a larger extent than did in kaolinite-coated sand under the test conditions; this was likely related to the differences of physicochemical characteristics between goethite and kaolinite. Organic acids significantly inhibited the deposition of GO at 0.5 mM Ca2+; this was possible that Ca2+ enhanced adsorption of organic acids by complexing with the surface O-functionalities of both LMWOAs and sand grain. Consequently, more organic acid molecules competed with GO for deposition sites on grain surfaces. Additionally, a two-site transport model was used to fit the transport data. Our findings have important implications for the understanding of the deposition and fate of GO in soil especially in rhizosphere environments where various low-molecular-weight organic acids are active.


Assuntos
Ácidos Carboxílicos/química , Grafite/análise , Nanopartículas/análise , Poluentes do Solo/análise , Adsorção , Grafite/química , Compostos de Ferro/química , Caulim/química , Minerais/química , Peso Molecular , Nanopartículas/química , Dióxido de Silício/química , Solo/química , Poluentes do Solo/química , Eletricidade Estática
20.
Artigo em Inglês | MEDLINE | ID: mdl-31091807

RESUMO

Mass balance models have proved to be effective tools for exposure prediction in occupational settings. However, they are still not extensively tested in real-world scenarios, or for particle number concentrations. An industrial scenario characterized by high emissions of unintentionally-generated nanoparticles (NP) was selected to assess the performance of a one-box model. Worker exposure to NPs due to thermal spraying was monitored, and two methods were used to calculate emission rates: the convolution theorem, and the cyclic steady state equation. Monitored concentrations ranged between 4.2 × 104-2.5 × 105 cm-3. Estimated emission rates were comparable with both methods: 1.4 × 1011-1.2 × 1013 min-1 (convolution) and 1.3 × 1012-1.4 × 1013 min-1 (cyclic steady state). Modeled concentrations were 1.4-6 × 104 cm-3 (convolution) and 1.7-7.1 × 104 cm-3 (cyclic steady state). Results indicated a clear underestimation of measured particle concentrations, with ratios modeled/measured between 0.2-0.7. While both model parametrizations provided similar results on average, using convolution emission rates improved performance on a case-by-case basis. Thus, using cyclic steady state emission rates would be advisable for preliminary risk assessment, while for more precise results, the convolution theorem would be a better option. Results show that one-box models may be useful tools for preliminary risk assessment in occupational settings when room air is well mixed.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Modelos Teóricos , Nanopartículas/análise , Exposição Ocupacional/análise , Medição de Risco/métodos , Monitoramento Ambiental/métodos , Humanos , Indústrias , Tamanho da Partícula
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