Nanomaterials (NMs) are gaining increasing commercial importance due to a variety of properties that cannot be achieved with bulk materials. Yet the assessment of their environmental impacts lags ...behind the technological development. First attempts towards designing inherently safer NMs have been made, yet we are still unable to formulate rules of green nano-design, especially in terms of mitigating (long-term) toxicity and bioaccumulation. Importantly, NMs released to the environment acquire a so called 'environmental corona' - a complex layer of spontaneously adsorbed biomolecules - that significantly impacts their behaviour and fate. This review integrates the current literature on the impact of environmental conditions on NMs fate and behaviour, including corona formation, colloidal stability, reactivity, and toxicty, using a broad range of environmentally relevant NMs. Collectively, components of natural waters (such as salts and/or natural organic matter) often mitigate negative impacts of NMs
via
different mechanisms including surface passivation and stabilisation against dissolution. The review concludes by discussing some initial strategies on how to rationally design more environmentally acceptable NMs.
Components of natural waters (salts, NOM) mitigate negative impacts of nanomaterials
via
surface passivation and stabilisation against dissolution.
As agriculture strives to feed an ever-increasing number of people, it must also adapt to increasing exposure to minute plastic particles. To learn about the accumulation of nanoplastics by plants, ...we prepared well-defined block copolymer nanoparticles by aqueous dispersion polymerisation. A fluorophore was incorporated via hydrazone formation and uptake into roots and protoplasts of Arabidopsis thaliana was investigated using confocal microscopy. Here we show that uptake is inversely proportional to nanoparticle size. Positively charged particles accumulate around root surfaces and are not taken up by roots or protoplasts, whereas negatively charged nanoparticles accumulate slowly and become prominent over time in the xylem of intact roots. Neutral nanoparticles penetrate rapidly into intact cells at the surfaces of plant roots and into protoplasts, but xylem loading is lower than for negative nanoparticles. These behaviours differ from those of animal cells and our results show that despite the protection of rigid cell walls, plants are accessible to nanoplastics in soil and water.
The call for adaptive governance approaches to guide the sustainable transformation of urban water management systems is growing amongst scholars and policy professionals. Responding to this call, ...the Global North (GN) has focused significant evidence-based research on issues of scale, capacity, and institutional arrangements to support such transformations, whereas evidence from the Global South remains nascent. This paper contributes to the growing body of knowledge from the Global South, discussing how adaptive governance operates under different local contexts and conditions. Following empirical investigations in two cities in Bangladesh, which involved 58 semi-structured interviews, 17 oral histories, and secondary data analysis, and drawing on the adaptive capacity and attributes framework, we examined how scale, capacity, and institutional hybridization might deliver the conditions necessary for guiding a sustainable transformation in water governance. The research revealed that a large-scale urban system such as Dhaka is currently experiencing “lock-in” due to ongoing investments in large-scale infrastructure, inappropriate transfer of technology from GN contexts, bureaucratic complexity, and general resistance to change. In contrast, the relatively smaller urban system represented by the secondary city Mymensingh was found to be more open, flexible, showcasing key enabling factors that might support sustainable growth. Overall, this study sheds light on the role of adaptive governance in the context of system scales and capacity (i.e., institutional / organizational / individual) and reveals how capacity development is linked to key enabling attributes including multi-level and polycentric institutions, participatory approaches, networking, bridging organizations, and leadership. Collectively these findings offer insights into how adaptive attributes can inform sustainable transformation processes
Nucleation of protein fibrillation by nanoparticles Linse, Sara; Cabaleiro-Lago, Celia; Xue, Wei-Feng ...
Proceedings of the National Academy of Sciences - PNAS,
05/2007, Volume:
104, Issue:
21
Journal Article
Peer reviewed
Open access
Nanoparticles present enormous surface areas and are found to enhance the rate of protein fibrillation by decreasing the lag time for nucleation. Protein fibrillation is involved in many human ...diseases, including Alzheimer's, Creutzfeld-Jacob disease, and dialysis-related amyloidosis. Fibril formation occurs by nucleation-dependent kinetics, wherein formation of a critical nucleus is the key rate-determining step, after which fibrillation proceeds rapidly. We show that nanoparticles (copolymer particles, cerium oxide particles, quantum dots, and carbon nanotubes) enhance the probability of appearance of a critical nucleus for nucleation of protein fibrils from human β₂-microglobulin. The observed shorter lag (nucleation) phase depends on the amount and nature of particle surface. There is an exchange of protein between solution and nanoparticle surface, and β₂-microglobulin forms multiple layers on the particle surface, providing a locally increased protein concentration promoting oligomer formation. This and the shortened lag phase suggest a mechanism involving surface-assisted nucleation that may increase the risk for toxic cluster and amyloid formation. It also opens the door to new routes for the controlled self-assembly of proteins and peptides into novel nanomaterials.
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Nanoparticles (NPs) are defined as having at least one external dimension between 1 and 100 nm. Due to their small size, NPs have a large surface area to volume ratio giving them unique ...characteristics that differ from bulk material of the same chemical composition. As a result these novel materials have found numerous applications in medical and industrial fields with the result that environmental exposure to NPs is increasingly likely. Similarly, increased reliance on plastic, which degrades extremely slowly in the environment, is resulting in increased accumulation of micro-/nano-plastics in fresh and marine waters, whose ecotoxicological impacts are as yet poorly understood. Although NPs are well known to adsorb macromolecules from their environment, forming a biomolecule corona which changes the NP identity and how it interacts with organisms, significantly less research has been performed on the ecological corona (eco-corona). Secretion of biomolecules is a well established predator–prey response in aquatic food chains, raising the question of whether NPs interact with secreted proteins, and the impact of such interaction on NP uptake and ecotoxicity. We report here initial studies, including optimisation of protocols using carboxylic-acid and amino modified spherical polystyrene NPs, to assess interaction of NPs with biomolecules secreted by Daphnia magna and the impact of these interactions on NP uptake, retention and toxicity towards Daphnia magna.
Daphnia magna are an important environmental indicator species who may be especially sensitive to nanoparticles (NPs) as a result of being filter-feeders. This paper demonstrates for the first time that proteins released by Daphnia magna create an eco-corona around polystyrene NPs which causes heightened uptake of the NPs and consequently increases toxicity. The secreted protein eco-corona also causes the NPs to be less efficiently removed from the gut of D. magna and NPs remaining in the gut of D. magna affected the rate of subsequent feeding. Thus, fate of NPs in the environment should be evaluated and monitored under more realistic exposure scenarios.
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•Conditioning media by exposing to D. magna neonates resulted in significant release of proteins•Secreted proteins coated COOH- or NH2-PS NPs forming an eco-corona•Eco-corona-coated NPs had lower EC50 than uncoated NPs; NH2-PS NPs were more toxic than COOH-PS NPs with/without eco-corona•Higher retention of corona-coated NPs in D. magna gut post-exposure, affecting feeding ability•OECD protocols need revision for NP toxicity: corona formation, NP retention and feeding effects should be considered.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In a biological environment, nanoparticles immediately become covered by an evolving corona of biomolecules, which gives a biological identity to the nanoparticle and determines its biological impact ...and fate. Previous efforts at describing the corona have concerned only its protein content. Here, for the first time, we show, using size exclusion chromatography, NMR, and pull-down experiments, that copolymer nanoparticles bind cholesterol, triglycerides and phospholipids from human plasma, and that the binding reaches saturation. The lipid and protein binding patterns correspond closely with the composition of high-density lipoprotein (HDL). By using fractionated lipoproteins, we show that HDL binds to copolymer nanoparticles with much higher specificity than other lipoproteins, probably mediated by apolipoprotein A-I. Together with the previously identified protein binding patterns in the corona, our results imply that copolymer nanoparticles bind complete HDL complexes, and may be recognized by living systems as HDL complexes, opening up these transport pathways to nanoparticles. Apolipoproteins have been identified as binding to many other nanoparticles, suggesting that lipid and lipoprotein binding is a general feature of nanoparticles under physiological conditions.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Central to understanding how nanoscale objects interact with living matter is the need for reproducible and verifiable data that can be interpreted with confidence. Likely this will be the ...basis of durable advances in nanomedicine and nanomedical safety. To develop these fields, there is also considerable interest in advancing the first generation of theoretical models of nanoparticle (NP) uptake into cells, and NP biodistribution in general. Here we present an uptake study comparing the outcomes for free molecular dye and NPs labeled with the same dye. A simple flux-based approach is presented to model NP uptake. We find that the intracellular NP concentration grows linearly in time, and that the uptake is essentially irreversible, with the particles accumulating in lysosomes. A wide range of practical challenges, from labile dye release to NP aggregation and the need to account for cell division, are addressed to ensure that these studies yield meaningful kinetic information. From the Clinical Editor The authors present an uptake study comparing the outcomes for free molecular dye and NPs labeled with the same dye. A wide range of practical challenges are addressed including labile dye release, NP aggregation and the need to account for cell division with the goal that these studies yield meaningful kinetic information.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Blood relations: Nanoparticles that enter the bloodstream become coated with proteins. Four apolipoproteins are consistently recovered on model copolymer nanoparticles by using a centrifugation ...procedure (see electropherogram); their interaction with the nanoparticles is stronger than that of other plasma proteins with higher abundance.
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Engineered Nanomaterials (NMs), such as Superparamagnetic Iron Oxide Nanoparticles (SPIONs), offer significant benefits in a wide range of applications, including cancer diagnostic and therapeutic ...strategies. However, the use of NMs in biomedicine raises safety concerns due to lack of knowledge on possible biological interactions and effects. The initial basis for using SPIONs as biomedical MRI contrast enhancement agents was the idea that they are selectively taken up by macrophage cells, and not by the surrounding cancer cells. To investigate this claim, we analyzed the uptake of SPIONs into well-established cancer cell models and benchmarked this against a common macrophage cell model. In combination with fluorescent labeling of compartments and siRNA silencing of various proteins involved in common endocytic pathways, the mechanisms of internalization of SPIONs in these cell types has been ascertained utilizing reflectance confocal microscopy. Caveolar mediated endocytosis and macropinocytosis are both implicated in SPION uptake into cancer cells, whereas in macrophage cells, a clathrin-dependant route appears to predominate. Colocalization studies confirmed the eventual fate of SPIONs as accumulation in the degradative lysosomes. Dissolution of the SPIONs within the lysosomal environment has also been determined, allowing a fuller understanding of the cellular interactions, uptake, trafficking and effects of SPIONs within a variety of cancer cells and macrophages. Overall, the behavior of SPIONS in non-phagocytotic cell lines is broadly similar to that in the specialist macrophage cells, although some differences in the uptake patterns are apparent.
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IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Nanoparticles in biological fluids almost invariably become coated with proteins that may confer nanomedical and nanotoxicological effects. Understanding these effects requires quantitative ...measurements using simple systems. Adsorption of HSA to copolymer nanoparticles of varying hydrophobicity and curvature was studied using ITC, yielding stoichiometry, affinity, and enthalpy changes upon binding. The hydrophobicity was controlled via the co-monomer ratio, N-iso-propylacrylamide/N-tert-butylacrylamide. The most hydrophobic particles become fully covered with a single layer of protein, except at high curvature.
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