Fate Of Nanoparticles Research Articles

Adsorption of gold nanoparticles on illite under high solid/liquid ratio and initial pH conditions

AbstractAdsorption of nanoparticles on minerals affects the fate and transport of nanoparticles directly and is of great significance to many fields, including research into ore deposits, geochemistry, the environment and mineral materials. Whereas many previous studies have been conducted under the equilibrium pH and low solid (mineral) to liquid (nanoparticle suspension) ratio conditions, adsorption processes under initial pH and high solid/liquid ratio conditions may represent many important yet underexamined complex scenarios. To fill in this research gap, the adsorption of gold nanoparticles on illite was investigated experimentally at a relatively high solid/liquid ratio of 5 g L–1 and the effects of initial pH, ionic strength, citrate concentration, temperature and illite particle size were evaluated. The adsorbed amount of gold nanoparticles (from <5% to nearly 100%) increased with increasing ionic strength, temperature and citrate concentration and decreased with increasing pH and illite particle size. The presence of illite resulted in the dynamic evolution of the pH of the suspension, which, along with solution chemistry parameters, controlled the electrostatic interaction of illite and gold nanoparticles. The adsorption results, scanning electron microscopy observations and surface properties of illite suggest that the negatively charged gold nanoparticles were adsorbed predominantly on the positive illite edges through electrostatic interaction. The electrostatic attraction between illite and gold nanoparticles appeared to be strong, supported by the minor amount of desorption. These research findings are expected to provide a valuable reference regarding many critical issues in the geosciences as well as for industrial applications.

Averaging Strategy for Interpretable Machine Learning on Small Datasets to Understand Element Uptake after Seed Nanotreatment.

Understanding plant uptake and translocation of nanomaterials is crucial for ensuring the successful and sustainable applications of seed nanotreatment. Here, we collect a dataset with 280 instances from experiments for predicting the relative metal/metalloid concentration (RMC) in maize seedlings after seed priming by various metal and metalloid oxide nanoparticles. To obtain unbiased predictions and explanations on small datasets, we present an averaging strategy and add a dimension for interpretable machine learning. The findings in post-hoc interpretations of sophisticated LightGBM models demonstrate that solubility is highly correlated with model performance. Surface area, concentration, zeta potential, and hydrodynamic diameter of nanoparticles and seedling part and relative weight of plants are dominant factors affecting RMC, and their effects and interactions are explained. Furthermore, self-interpretable models using the RuleFit algorithm are established to successfully predict RMC only based on six important features identified by post-hoc explanations. We then develop a visualization tool called RuleGrid to depict feature effects and interactions in numerous generated rules. Consistent parameter-RMC relationships are obtained by different methods. This study offers a promising interpretable data-driven approach to expand the knowledge of nanoparticle fate in plants and may profoundly contribute to the safety-by-design of nanomaterials in agricultural and environmental applications.

Fate of Magnetic Nanoparticles during Stimulated Healing of Thermoplastic Elastomers.

We have investigated the heating mechanism in industrially relevant, multi-block copolymers filled with Fe nanoparticles and subjected to an oscillatory magnetic field that enables polymer healing in a contactless manner. While this procedure aims to extend the lifetime of a wide range of thermoplastic polymers, repeated or prolonged stimulus healing is likely to modify their structure, mechanics, and ability to heat, which must therefore be characterized in depth. In particular, our work sheds light on the physical origin of the secondary heating mechanism detected in soft systems subjected to magnetic hyperthermia and triggered by copolymer chain dissociation. In spite of earlier observations, the origin of this additional heating remained unclear. By using both static and dynamic X-ray scattering methods (small-angle X-ray scattering and X-ray photon correlation spectroscopy, respectively), we demonstrate that beyond magnetic hysteresis losses, the enormous drop of viscosity at the polymer melting temperature enables motion of nanoparticles that generates additional heat through friction. Additionally, we show that applying induction heating for a few minutes is found to magnetize the nanoparticles, which causes them to align in dipolar chains and leads to nonmonotonic translational dynamics. By extrapolating these observations to rotational dynamics and the corresponding amount of heat generated through friction, we not only clarify the origin of the secondary heating mechanism but also rationalize the presence of a possible temperature maximum observed during induction heating.

Biotic and Abiotic Interactions in Freshwater Mesocosms Determine Fate and Toxicity of CuO Nanoparticles.

Transformation, dissolution, and sorption of copper oxide nanoparticles (CuO-NP) play an important role in freshwater ecosystems. We present the first mesocosm experiment on the fate of CuO-NP and the dynamics of the zooplankton community over a period of 12 months. Increasingly low (0.08-0.28 mg Cu L-1) and high (0.99-2.99 mg Cu L-1) concentrations of CuO-NP and CuSO4 (0.10-0.34 mg Cu L-1) were tested in a multiple dosing scenario. At the high applied concentration (CuO-NP_H) CuO-NP aggregated and sank onto the sediment layer, where we recovered 63% of Cu applied. For the low concentration (CuO-NP_L) only 41% of applied copper could be recovered in the sediment. In the water column, the percentage of initially applied Cu recovered was on average 3-fold higher for CuO-NP_L than for CuO-NP_H. Zooplankton abundance was substantially compromised in the treatments CuSO4 (p < 0.001) and CuO-NP_L (p < 0.001). Community analysis indicated that Cladocera were most affected (bk = -0.49), followed by Nematocera (bk = -0.32). The abundance of Cladocera over time and of Dixidae in summer was significantly reduced in the treatment CuO-NP_L (p < 0.001; p < 0.05) compared to the Control. Our results indicate a higher potential for negative impacts on the freshwater community when lower concentrations of CuO-NP (<0.1 mg Cu L-1) enter the ecosystem.

Cholesterol modulates the physiological response to nanoparticles by changing the composition of protein corona.

Nanoparticles (NPs) in biological fluids form a layer of biomolecules known as the protein corona. The protein corona has been shown to determine the biological identity and in vivo fate of NPs, but whether and how metabolites, especially disease-related small molecules, regulate the protein corona and subsequently impact NP fate in vivo is relatively poorly understood. Here we report on the effects of cholesterol on the generation of protein corona and subsequent effects. We find that high levels of cholesterol, as in hypercholesterolemia, result in a protein corona with enriched apolipoproteins and reduced complement proteins by altering the binding affinity of the proteins to the NPs. The cholesterol-mediated protein corona can induce stronger inflammatory responses to NPs in macrophages and promote the cellular uptake of NPs in hepatocytes by enhancing the recognition of lipoprotein receptors when compared with normal protein corona. The result of in vivo biodistribution assays shows that, compared with healthy mice, NPs in hypercholesterolemic mice were more likely to be delivered to the liver, spleen and brain, and less likely to be delivered to the lungs. Our findings reveal that the metabolome profile is an unexploited factor impacting the target efficacy and safety of nanomedicines, providing a way to develop personalized nanomedicines by harnessing disease-related metabolites.

Joanna Szpunar, a great chemical researcher internationally recognized, kindly spoke to BrJAC

Joanna Szpunar graduated from the Warsaw University of Technology in 1986 and obtained her Ph.D. (1992) and D.Sc. (Habilitation) (2000) from the University of Warsaw. Since 1997, she works at the National Research Council of France (CNRS). In 2007, she obtained in Poland the title of professor of chemistry. She has broad experience in the field of mass spectrometry-based bio-inorganic speciation analysis and metallomics with a focus on the identification and quantification of trace element species in biological systems and in the chemistry of metal-biomolecule interactions. She is the co-author of a book and approximately 250 scientific publications in peer-reviewed international journals. Joanna Szpunar is a fellow of the Royal Society of Chemistry (UK) and has been, for many years, a member of the boards of Journal of Analytical Atomic Spectrometry' and Metallomics. She regularly gives invited lectures at international analytical chemistry meetings and was the chairperson of the European Winter Conference on Plasma Spectrochemistry (Kraków, Poland) in 2013. The investigations carried out under her supervision and/or with her active participation resulted in the identification of a number of molecular targets of metals in biological systems, as well as contribute to selenometabolomics and selenoproteomics studies in bacteria and plants. In recent years, her interests were broadened to the environmental fate of metal-containing nanoparticles and nanoplastics. She has supervised 12 Ph.D. theses and several post-doctoral fellows. Joanna Szpunar is the laureate of the 2013 Jerzy Fijalkowski Award of the Committee of Analytical Chemistry of the Polish Academy of Sciences and the 2017 European Award for Plasma Spectrochemistry. In recent years, Joanna Szpunar has been involved in collaboration with analytical chemists in Brazil, hosting graduate students from the University of Campinas and the Federal University of Pelotas in the laboratory at the Institute of Analytical Sciences (IPREM) in Pau afiliated with the CNRS, lecturing at the Federal University of Santa Maria and co-supervising a Ph.D. student with work carried out at the University of Pau and the Federal University of Pelotas.

A comprehensive physicochemical characterization of zinc oxide nanoparticles extracted from sunscreens and wastewaters

The widespread popularity of sunscreens contributes significantly to the release of zinc oxide (ZnO) nanoparticles into bodies of water, yet there is still lack of sufficient understanding on the realistic behaviour and long-term exposure. In this study, a simple and effective method was used to extract ZnO nanoparticles from ZnO-based sunscreen products (available in Australia) that end up in wastewaters. The extracted ZnO nanoparticles were negative charged at controlled pH 7. Transmission electron microscopy (TEM) analysis revealed an irregular, spherical and rod-shaped nanoparticles extracted from sunscreens and wastewaters with size ≥100 nm. Various nanoparticles containingZnO, iron, silver, and titanium were detected in wastewater samples collected from treatment plants. Other contaminants were also found in the wastewater samples based on TEM elemental analysis. The results documented in this study are useful to understand the presence and characterizations of ZnO nanoparticles in sunscreens and wastewaters. With this knowledge, we can realistically investigate the fate, behaviours and adverse effects of ZnO nanoparticles.

Unravelling the role of lipid composition on liposome-protein interactions

Upon in vivo administration of nanoparticles, a protein corona forms on their surface and affects their half-life in circulation, biodistribution properties, and stability; in turn, the composition of the protein corona depends on the physico-chemical properties of the nanoparticles. We have previously observed lipid composition-dependent in vitro and in vivo microRNA delivery from lipid nanoparticles. Here, we carried out an extensive physico-chemical characterisation to understand the role of the lipid composition on the in vivo fate of lipid-based nanoparticles. We used a combination of differential scanning calorimetry (DSC), membrane deformability measurements, isothermal titration calorimetry (ITC), and dynamic light scattering (DLS) to probe the interactions between the nanoparticle surface and bovine serum albumin (BSA) as a model protein. The lipid composition influenced membrane deformability, improved lipid intermixing, and affected the formation of lipid domains while BSA binding to the liposome surface was affected by the PEGylated lipid content and the presence of cholesterol. These findings highlight the importance of the lipid composition on the protein-liposome interaction and provide important insights for the design of lipid-based nanoparticles for drug delivery applications.

β-Lactoglobulin stabilized lipid nanoparticles enhance oral absorption of insulin by slowing down lipolysis

Lipid-based nanocarriers have staged a remarkable comeback in the oral delivery of proteins and peptides, but delivery efficiency is compromised by lipolysis. β-Lactoglobulin (β-lg) stabilized lipid nanoparticles, including nanoemulsions (NE@β-lg) and nanocapsules (NC@β-lg), were developed to enhance the oral absorption of insulin by slowing down lipolysis due to the protection from β-lg. Cremophor EL stabilized nanoemulsions (NE@Cre-EL) were prepared and set as a control. The lipid nanoparticles produced mild and sustained hypoglycemic effects, amounting to oral bioavailability of 3.0% ± 0.3%, 7.0% ± 1.1%, and 7.7% ± 0.8% for NE@Cre-EL, NE@β-lg, and NC@β-lg, respectively. Aggregation-caused quenching (ACQ) probes enabled the identification of intact nanoparticles, which were used to investigate the in vivo and intracellular fates of the lipid nanoparticles. In vitro digestion/lipolysis and ex vivo imaging confirmed delayed lipolysis from β-lg stabilized lipid nanoparticles. NC@β-lg was more resistant to intestinal lipolysis than NE@β-lg due to the Ca2+-induced crosslinking. Live imaging revealed the transepithelial transport of intact nanoparticles and their accumulation in the liver. Cellular studies confirmed the uptake of intact nanoparticles. Slowing down lipolysis via food proteins represents a good strategy to enhance the oral absorption of lipid nanoparticles and thus co-formulated biomacromolecules.

A Novel Strategy for Visualizing, Tracing, and Measuring the Gastrointestinal Absorption of Silver Nanoparticles

AbstractThe silver‐based formulation has become one of the most widely used nanoagents for agrifood industry and clinical translation. However, the in vivo fate of silver nanoparticles (AgNPs) via oral exposure remains poorly understood. Here, a specific strategy is shown for tracking the gastrointestinal transformation, intestinal absorption, and organ distribution of particulate Ag after oral exposure by using the gold (Au)‐Ag core−shell NPs (Au@AgNPs). Taking advantage of both plasmonic and elemental characteristics of Au@AgNPs, the transformation of particulate Ag in the gastrointestinal tract (GIT), and later on, intestinal absorption are visualized at the single‐particle level. Furthermore, quantitative analysis reveals that the clearance rate of ingested particulate Ag from the blood and organs is much higher than that of ionic Ag, and at 6 h post‐oral administration, the former only contributed 0.08%, 1.10%, and 0.64% of the total Ag in the liver, spleen, and kidneys. Finally, the transcellular and paracellular pathways are identified as two possible mechanisms responsible for the transepithelial transport of particulate Ag. This study opens an avenue toward the examination of oral bioavailability of NPs and may have important implications in exploring the oral delivery technologies of nanoagents.

Digestion kinetics and molecular structural evolution during in vitro digestion of green banana (cv. Giant Cavendish) starch nanoparticles

Knowledge of digestion mechanism of starch nanoparticles are crucial for their utilization and potential applications. In this study, molecular structural evolution and digestion kinetics of starch nanoparticles from green banana (GBSNPs) during digestion (0–180 min) was investigated. Distinctive topographic changes of the GBSNPs during digestion with decreased particle size and increased surface roughness were detected. The GBSNPs showed markedly decreased average molecular weight and polydispersity in the initial digestion phase (0–20 min), and these two structural characteristics remained nearly unchanged thereafter. The GBSNPs exhibited a B-type polymorph throughout digestion, while their crystallinity decreased with increasing digestion duration. The infrared spectra revealed that the initial digestion phase led to the increased absorbance ratios 1047/1022 and 1047/1035 cm−1, reflecting the markedly increased short-range molecular order that was substantiated by the blue-shifting of COH-bending band. Logarithm of slope analysis of digestogram revealed that the GBSNPs were digested by a two-phase process that reflected the surface barrier effect exerted by the increased short-range order. The short-range molecular order strengthening induced from the initial digestion phase was responsible for the increased enzymatic resistance. The results can help to elucidate the gastrointestinal fate of starch nanoparticles for their potential applications as health-promoting ingredients.

Exploring the Effect of Drug Loading on the Biological Fate of Polymer-Coated Solid Nanoparticles

Polymer-coated inorganic nanoparticles (NPs) have attracted great attention in drug delivery fields due to their unique magnetic, optical, and thermal properties. Recent studies have shown that the surface physicochemical properties of these NPs, including the size, shape, shell hydration, protein corona, and so forth, affect their biological fate. However, there has been less attention on the effect of the drug loading amount on the biological activity of inorganic NPs. Here, we used upconverting NPs (UCNPs) as an inorganic nanocarrier model, coated them with a triblock terpolymer poly(poly(ethylene glycol) methyl ether methacrylate)-block-polymethacrylic acid-block-ethylene glycol methacrylate phosphate (PPEGMEMA-b-PMAA-b-PEGMP), and loaded them with different amounts of anticancer drug doxorubicin (DOX) by electrostatic interactions. Our results show that the UCNPs with the lowest DOX loading amount (1.32%) have the best biological behavior. We find that the effect of DOX loading on the biological behavior of UCNPs is dominated by polymer shell hydration and the protein corona. The lowest drug-loading UCNPs are more hydrated and have more albumin coronas around, which leads to an increasing effect on the association with cancer cells and drug accumulation in the mouse tumor area. Our findings highlight the importance of optimizing the drug loading amounts in polymer-coated inorganic drug delivery systems as the amount and type of drug will alter the physical properties of the polymer shell.

Nanoparticle Spikes Enhance Cellular Uptake via Regulating Myosin IIA Recruitment.

Spike-like nanostructures are omnipresent in natural and artificial systems. Although biorecognition of nanostructures to cellular receptors has been indicated as the primary factor for virus infection pathways, how the spiky morphology of DNA-modified nanoparticles affects their cellular uptake and intracellular fate remains to be explored. Here, we design dually emissive gold nanoparticles with varied spikiness (from 0 to 2) to probe the interactions of spiky nanoparticles with cells. We discovered that nanospikes at the nanoparticle regulated myosin IIA recruitment at the cell membrane during cellular uptake, thereby enhancing cellular uptake efficiency, as revealed by dual-modality (plasmonic and fluorescence) imaging. Furthermore, the spiky nanoparticles also exhibited facilitated endocytosis dynamics, as revealed by real-time dark-field microscopy (DFM) imaging and colorimetry-based classification algorithms. These findings highlight the crucial role of the spiky morphology in regulating the intracellular fate of nanoparticles, which may shed light on engineering theranostic nanocarriers.

60 Multimodal Imaging and Artificial Intelligence Unveil Hot-Spot Deposition, Bronchial/Alveolar Dose and Cellular Fate of Biopersistent Nanoparticles in the Lung

Abstract Pulmonary delivery is not only of increasing importance to exploit local therapy for lung diseases like COVID-19, but also plays an essential role in interpreting health impact of inhaled hazardous (nano-)materials. Deciphering of biodistribution, biokinetics, and cell-mediated immunity of pulmonary delivered nanoparticles (NPs) remains insufficient. We applied state-of-the-art multimodal imaging and deep learning pipelines to elucidate the intricate deposition profiles and the fate of biopersistent NPs in the lung within cellular resolution. Spatially resolved delivery characteristics like inter- and intra-acinar distribution pattern and regional NP dosage were revealed by tissue-clearing light-sheet fluorescence microscopy for six common routes of pulmonary delivery, i.e., intranasal &amp; oropharyngeal aspiration, intubated instillation, microsprayer application, ventilator-assisted &amp; nose-only aerosol inhalation. Artificial intelligence-driven entire airway 3D segmentation (convolutional neural network) enabled accurate dosimetry of bronchial versus acinar/alveolar NP dose (B/A: 0.04 to 0.18 depending on delivery route) rather than the conventionally simplified 2D central-to-peripheral ratio (C/P: 1.32 to 3.79). Moreover, longitudinal 3D imaging revealed similar intra-acinar NP kinetics independent of delivery route. Inhaled NP relocation from the alveolar-epithelium to interstitium was traditionally claimed as the consequence of passive diffusion/transportation of NPs. This study, however, revealed that acinar NP transport can be attributed to the phagocytosis and migration of tissue-resident macrophages (TRMs) as evidenced by complementary analytical approaches (intravital microscopy, ex vivo 4D live-tissue microscopy, in situ immunofluorescence, ex vivo NP-lung interaction model, flow cytometry). Overall, this study elucidates holistic NP-lung delivery and biokinetics features and TRM immunity on the fate of biopersistent NPs.

89 Lung Single Cell Transcriptomics to Guide the Development of AOP Anchored Cell-Based Assays in Response to Nanoparticle Exposure

Abstract Inhaled nanoparticles (NP) can cause acute and chronic inflammation. Here we seek to identify NP-specific cellular perturbation pathways and the underlying key cell types to inform adverse outcome pathway (AOP) anchored in vitro studies, by single cell transcriptomics. We exposed mice intratracheally to carbon black (CNP), tangled double-walled (DWCNT) and rigid, multi-walled carbon nanotubes (MWCNT). All lungs underwent single-cell RNA sequencing (scRNA-seq), histology and BAL analysis. At the chosen doses all NPs caused comparable airspace neutrophilia at 12h, which increased until d6 for the CNTs but remained elevated until d28 only for MWCNT, indicating the key event (KE) acute and chronic inflammation. Comparing scRNA-seq and BAL cytokine levels at 12h, differentiated the fate of inflammation NP specifically. In agreement with airspace neutrophilia, CNP uniquely triggered GM-CSF and CXCL1 release, with Csf2 and Cxcl1 mRNAs being expressed mainly in alveolar epithelial cells. DWCNT caused CCL2, -3 and -4 release involving interstitial macrophages and monocytes, associated with acute high lung monocyte and at d6 high BAL macrophage numbers. MWCNT in contrast caused ample BAL cytokine increases involving different cell types and specifically caused a Th2 cytokine response (CCL11, IL10), a crucial KE of fibrosis AOPs. MWCNT triggered cell communication analysis uncovered NP-specific networks including epithelial cells, fibroblasts, macrophages, dendritic cells and endothelial cells. Our study uncovers early NP-specific cell perturbations and identified first specific cellular response pattern to guide AOP predictive cell-based testing strategies. Further analysis of the cellular dynamics shall enhance our understanding of NP specific cell circuits and related pathologies.

How eluents define proteomic fingerprinting of protein corona on nanoparticles

Nanoparticles (NPs) have broad application prospects in the field of biomedicine due to their excellent physicochemical properties. When entering biological fluids, NPs inevitably encountered proteins and were subsequently surrounded by them, forming the termed protein corona (PC). As PC has been evidenced to have critical roles in deciding the biological fates of NPs, how to precisely characterize PC is vital to promote the clinical translation of nanomedicine by understanding and harnessing NPs’ behaviors. During the centrifugation-based separation techniques for the PC preparation, direct elution has been most widely used to strip proteins from NPs due to its simpleness and robustness, but the roles of multifarious eluents have never been systematically declared. Herein, seven eluents composed of three denaturants, sodium dodecyl sulfate (SDS), dithiothreitol (DTT), and urea (Urea), were applied to detach PC from gold nanoparticles (AuNPs) and silica nanoparticles (SiNPs), and eluted proteins in PC have been carefully characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and chromatography coupled tandem mass spectrometry (LC-MS/MS). Our results showed that SDS and DTT were the main contributors to the efficient desorption of PC on SiNPs and AuNPs, respectively. The molecular reactions between NPs and proteins were explored and verified by SDS-PAGE analysis of PC formed in the serums pretreated with protein denaturing or alkylating agents. The proteomic fingerprinting analysis indicated the difference of the eluted proteins brought by the seven eluents was the abundance rather than the species. The enrichment of some opsonins and dysopsonins in a special elution reminds us that the possibility of biased judgments on predicting NPs’ biological behaviors under different elution conditions. The synergistic effects or antagonistic effects among denaturants for eluting PC were manifested in a nanoparticle-type dependent way by integrating the properties of the eluted proteins. Collectively, this study not only underlines the urgent need of choosing the appropriate eluents for identifying PC robustly and unbiasedly, but also provides an insight into the understanding of molecular interactions during PC formation.

Uncovering the Fate and Risks of Intravenously Injected Prussian Blue Nanoparticles in mice by an Integrated Methodology of Toxicology, Pharmacokinetics, Proteomics, and Metabolomics

BackgroundPrussian blue (PB) nanoparticles (NPs) have been intensively investigated for medical applications, but an in-depth toxicological investigation of PB NPs has not been implemented. In the present study, a comprehensive investigation of the fate and risks of PB NPs after intravenous administration was carried out by using a mouse model and an integrated methodology of pharmacokinetics, toxicology, proteomics, and metabolomics.ResultsGeneral toxicological studies demonstrated that intravenous administration of PB NPs at 5 or 10 mg/kg could not induce obvious toxicity in mice, while mice treated with a relatively high dose of PB NPs at 20 mg/kg exhibited loss of appetite and weight decrease in the first two days postinjection. Pharmacokinetic studies revealed that intravenously administered PB NPs (20 mg/kg) underwent fast clearance from blood, highly accumulated in the liver and lungs of mice, and finally cleared from tissues. By further integrated proteomics and metabolomics analysis, we found that protein expression and metabolite levels changed significantly in the liver and lungs of mice due to the high accumulation of PB NPs, leading to slight inflammatory responses and intracellular oxidative stress.ConclusionsCollectively, our integrated experimental data imply that the high accumulation of PB NPs may cause potential risks to the liver and lungs of mice, which will provide detailed references and guidance for further clinical application of PB NPs in the future.

Effect of Soil Texture, Nanoparticle Size, and Incubation Period on the Dissolution of ZnO Nanoparticles

Zinc is an essential plant and human nutrient and its primary source is Zn-rich food consumption. The only way to enrich plants with Zn is through the application of Zn fertilizers including various chemical and organic sources of ZnO nanoparticles (NPs). The Zn bioavailability from ZnO NPs must be considered for their recommendation as a fertilizer, and very little is known about the efficacy of such fertilizers in the Hungarian soil environment. In the present investigation, we prepared ZnO NPs of different sizes and applied them in two distinct textures of soils (sandy loam (SL) and silty clay (SC)) in an incubation experiment. The prepared ZnO NPs were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). ZnO NPs were applied in both soil types at 500 mg L−1 in the form of a suspension, and ZnSO4 was applied in the form of a solution. The soils were incubated for 7 and 14 days. Column leaching was performed to analyze the dissolved Zn. Retained Zn in the soil matrix was extracted using 0.05 M EDTA. The results showed that approximately 21–23% and 10–13% higher Zn was observed in the pore water of SL and SC soils, respectively, when spiked with small-sized NPs compared to large-sized NPs, while 14–26% higher dissolved Zn was observed in SL soil compared to SC soil. It is concluded that the size of NPs and the soil texture are the main factors that play important roles in deciding the fate of NPs under an alkaline soil environment.

Environmental, health and safety assessment of nanoparticle application in drilling mud – Review

The rapid increase in the use of engineered nanoparticles in different industrial applications makes risk assessment on human health, ecosystem and the environment necessary. Health, safety and environmental (HSE) risks of a technology are an inseparable part of which it threatens all exposed employees. There has been an increase and public interest in nanotechnology because of its applications in several areas including, processing and engineering industries e.g., oil and gas, electronics, cosmetic, biomedical, agriculture, medicine and public health. The increased use of nanomaterials in various sectors has raised concerns about their impact on health and safety, as well as the environment. As nanomaterials become commonly and widely used in every sector, environmental and personal exposure to nanomaterials is therefore unavoidable and this has led researchers to gain interest in nanotoxicity. Based on this, this paper reviews the application of nanotechnology in drilling engineering, with a focus on drilling fluids and environmental concerns regarding their disposal after use. Meanwhile, combined with the risks of nanotechnology toxicity to both humans, the ecosystem and the environment, this paper expounds the challenges of nanotechnology in oil and gas, the cost of nanoparticle mud fluids, fate and behaviour of nanoparticles, and then puts forward future recommendations for safe disposal of ENPs in drilling fluids and other industrial applications.

Application of magnetic particle imaging to evaluate nanoparticle fate in rodent joints.

Nanoparticles are a promising approach for improving intra-articular drug delivery and tissue targeting. However, techniques to non-invasively track and quantify their concentration in vivo are limited, resulting in an inadequate understanding of their retention, clearance, and biodistribution in the joint. Currently, fluorescence imaging is often used to track nanoparticle fate in animal models; however, this approach has limitations that impede long-term quantitative assessment of nanoparticles over time. The goal of this work was to evaluate an emerging imaging modality, magnetic particle imaging (MPI), for intra-articular tracking of nanoparticles. MPI provides 3D visualization and depth-independent quantification of superparamagnetic iron oxide nanoparticle (SPION) tracers. Here, we developed and characterized a polymer-based magnetic nanoparticle system incorporated with SPION tracers and cartilage targeting properties. MPI was then used to longitudinally assess nanoparticle fate after intra-articular injection. Magnetic nanoparticles were injected into the joints of healthy mice, and evaluated for nanoparticle retention, biodistribution, and clearance over 6weeks using MPI. In parallel, the fate of fluorescently tagged nanoparticles was tracked using in vivo fluorescence imaging. The study was concluded at day 42, and MPI and fluorescence imaging demonstrated different profiles in nanoparticle retention and clearance from the joint. MPI signal was persistent over the study duration, suggesting NP retention of at least 42days, much longer than the 14days observed based on fluorescence signal. These data suggest that the type of tracer - SPIONs or fluorophores - and modality of imaging can affect interpretation of nanoparticle fate in the joint. Given that understanding particle fate over time is paramount for attaining insights about therapeutic profiles in vivo, our data suggest MPI may yield a quantitative and robust method to non-invasively track nanoparticles following intra-articular injection on an extended timeline.