Publications
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Antibody cooperative adsorption onto AuNPs and its exploitation to force natural killer cells to kill HIV-infected T cells
Astorga-Gamaza A., Vitali M., Borrajo M.L., Suárez-López R., Jaime C., Bastus N., Serra-Peinado C., Luque-Ballesteros L., Blanch-Lombarte O., Prado J.G., Lorente J., Pumarola F., Pellicer M., Falcó V., Genescà M., Puntes V., Buzon M.J. Nano Today; 36 (101056) 2021. 10.1016/j.nantod.2020.101056. IF: 20.722
HIV represents a persistent infection which negatively alters the immune system. New tools to reinvigorate different immune cell populations to impact HIV are needed. Herein, a novel nanotool for the specific enhancement of the natural killer (NK) immune response towards HIV-infected T-cells has been developed. Bispecific Au nanoparticles (BiAb-AuNPs), dually conjugated with IgG anti-HIVgp120 and IgG anti-human CD16 antibodies, were generated by a new controlled, linker-free and cooperative conjugation method promoting the ordered distribution and segregation of antibodies in domains. The cooperatively-adsorbed antibodies fully retained the capabilities to recognize their cognate antigen and were able to significantly enhance cell-to-cell contact between HIV-expressing cells and NK cells. As a consequence, the BiAb-AuNPs triggered a potent cytotoxic response against HIV-infected cells in blood and human tonsil explants. Remarkably, the BiAb-AuNPs were able to significantly reduce latent HIV infection after viral reactivation in a primary cell model of HIV latency. This novel molecularly-targeted strategy using a bispecific nanotool to enhance the immune system represents a new approximation with potential applications beyond HIV. © 2020 The Authors
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Cerium oxide nanoparticles: A new therapeutic tool in liver diseases
Casals G., Perramón M., Casals E., Portolés I., Fernández-Varo G., Morales-Ruiz M., Puntes V., Jiménez W. Antioxidants; 10 (5, 660) 2021. 10.3390/antiox10050660. IF: 6.313
Oxidative stress induced by the overproduction of free radicals or reactive oxygen species (ROS) has been considered as a key pathogenic mechanism contributing to the initiation and progression of injury in liver diseases. Consequently, during the last few years antioxidant substances, such as superoxide dismutase (SOD), resveratrol, colchicine, eugenol, and vitamins E and C have received increasing interest as potential therapeutic agents in chronic liver diseases. These substances have demonstrated their efficacy in equilibrating hepatic ROS metabolism and thereby improving liver functionality. However, many of these agents have not successfully passed the scrutiny of clinical trials for the prevention and treatment of various diseases, mainly due to their unspecificity and consequent uncontrolled side effects, since a minimal level of ROS is needed for normal functioning. Recently, cerium oxide nanoparticles (CeO2 NPs) have emerged as a new powerful antioxidant agent with therapeutic properties in experimental liver disease. CeO2 NPs have been reported to act as a ROS and reactive nitrogen species (RNS) scavenger and to have multi-enzyme mimetic activity, including SOD activity (deprotionation of superoxide anion into oxygen and hydrogen peroxide), catalase activity (conversion of hydrogen peroxide into oxygen and water), and peroxidase activity (reducing hydrogen peroxide into hydroxyl radicals). Consequently, the beneficial effects of CeO2 NPs treatment have been reported in many different medical fields other than hepatology, including neurology, ophthalmology, cardiology, and oncology. Unlike other antioxidants, CeO2 NPs are only active at pathogenic levels of ROS, being inert and innocuous in healthy cells. In the current article, we review the potential of CeO2 NPs in several experimental models of liver disease and their safety as a therapeutic agent in humans as well. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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Cross-species comparisons of nanoparticle interactions with innate immune systems: A methodological review
Swartzwelter B.J., Mayall C., Alijagic A., Barbero F., Ferrari E., Hernadi S., Michelini S., Pacheco N.I.N., Prinelli A., Swart E., Auguste M. Nanomaterials; 11 (6, 1528) 2021. 10.3390/nano11061528. IF: 5.076
Many components of the innate immune system are evolutionarily conserved and shared across many living organisms, from plants and invertebrates to humans. Therefore, these shared features can allow the comparative study of potentially dangerous substances, such as engineered nanoparticles (NPs). However, differences of methodology and procedure between diverse species and models make comparison of innate immune responses to NPs between organisms difficult in many cases. To this aim, this review provides an overview of suitable methods and assays that can be used to measure NP immune interactions across species in a multidisciplinary approach. The first part of this review describes the main innate immune defense characteristics of the selected models that can be associated to NPs exposure. In the second part, the different modes of exposure to NPs across models (considering isolated cells or whole organisms) and the main endpoints measured are discussed. In this synergistic perspective, we provide an overview of the current state of important cross-disciplinary immunological models to study NP-immune interactions and identify future research needs. As such, this paper could be used as a methodological reference point for future nano-immunosafety studies. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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Formation and evolution of the nanoparticle environmental corona: The case of Au and humic acid
Barbero F., Mayall C., Drobne D., Saiz-Poseu J., Bastús N.G., Puntes V. Science of the Total Environment; 768 (144792) 2021. 10.1016/j.scitotenv.2020.144792. IF: 7.963
Studying the behaviour of nanomaterials after their release into natural water is essential to understand the risk associated to their environmental exposure. In particular, the interaction and adsorption of dissolved organic matter onto nanoparticles strongly influence the behaviour and fate of nanomaterials in natural water systems. We herein study the interaction of Au and Ag nanoparticles and humic acids, the principal component of natural dissolved organic matter. Physicochemical characterization results showed the formation of an organic matter corona, consisting of two layers: a “hard” one, firmly bound to the nanoparticle surface, and a “soft” one, in dynamic equilibrium and, consequently, highly dependent on the media organic matter concentration. The extent of the electro-steric stabilization of the so called environmental corona depends on the size of the supramolecular association of humic acid (which depends on its hydrophilic and lipophilic moieties), the nanoparticle size, the total concentration of organic matter in the media, and the ratio between them. Interestingly, environmental coronas can eventually prevent Ca2+ and Mg2+ induced aggregation at concentrations range present in most of the freshwater bodies. The humic coating formed on top of the Au or control Ag nanoparticles presented a similar profile, but the corrodibility of Ag led to a more natural detachment of the corona. These results were further confirmed by exposing the nanoparticles to a model of natural water and standard mud (LUFA 2.2 dispersion). In the latter case, after several days, nanoparticle sedimentation was observed, which was attributed to interactions with macro organic and inorganic matter (fraction larger than particulate matter). © 2021 Elsevier B.V.
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Functional and morphological changes induced in mytilus hemocytes by selected nanoparticles
Auguste M., Mayall C., Barbero F., Hočevar M., Alberti S., Grassi G., Puntes V.F., Drobne D., Canesi L. Nanomaterials; 11 (2, 470): 1 - 16. 2021. 10.3390/nano11020470. IF: 5.076
Nanoparticles (NPs) show various properties depending on their composition, size, and surface coating, which shape their interactions with biological systems. In particular, NPs have been shown to interact with immune cells, that represent a sensitive surveillance system of external and internal stimuli. In this light, in vitro models represent useful tools for investigating nano-bio-interactions in immune cells of different organisms, including invertebrates. In this work, the effects of selected types of NPs with different core composition, size and functionalization (custom-made PVP-AuNP and commercial nanopolystyrenes PS-NH2 and PS-COOH) were investigated in the hemocytes of the marine bivalve Mytilus galloprovincialis. The role of exposure medium was evaluated using either artificial seawater (ASW) or hemolymph serum (HS). Hemocyte morphology was investigated by scanning electron microscopy (SEM) and different functional parameters (lysosomal membrane stability, phagocytosis, and lysozyme release) were evaluated. The results show distinct morphological and functional changes induced in mussel hemocytes depending on the NP type and exposure medium. Mussel hemocytes may represent a powerful alternative in vitro model for a rapid pre-screening strategy for NPs, whose utilization will contribute to the understanding of the possible impact of environmental exposure to NPs in marine invertebrates. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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Gold nanoparticles (AuNPs) impair LPS-driven immune responses by promoting a tolerogenic-like dendritic cell phenotype with altered endosomal structures
Michelini S., Barbero F., Prinelli A., Steiner P., Weiss R., Verwanger T., Andosch A., Lütz-Meindl U., Puntes V.F., Drobne D., Duschl A., Horejs-Hoeck J. Nanoscale; 13 (16): 7648 - 7666. 2021. 10.1039/d0nr09153g. IF: 7.790
Dendritic cells (DCs) shape immune responses by influencing T-cell activation. Thus, they are considered both an interesting model for studying nano-immune interactions and a promising target for nano-based biomedical applications. However, the accentuated ability of nanoparticles (NPs) to interact with biomolecules may have an impact on DC function that poses an unexpected risk of unbalanced immune reactions. Here, we investigated the potential effects of gold nanoparticles (AuNPs) on DC function and the consequences for effector and memory T-cell responses in the presence of the microbial inflammatory stimulus lipopolysaccharide (LPS). Overall, we found that, in the absence of LPS, none of the tested NPs induced a DC response. However, whereas 4-, 8-, and 11 nm AuNPs did not modulate LPS-dependent immune responses, 26 nm AuNPs shifted the phenotype of LPS-activated DCs toward a tolerogenic state, characterized by downregulation of CD86, IL-12 and IL-27, upregulation of ILT3, and induction of class E compartments. Moreover, this DC phenotype was less proficient in promoting Th1 activation and central memory T-cell proliferation. Taken together, these findings support the perception that AuNPs are safe under homeostatic conditions; however, particular care should be taken in patients experiencing a current infection or disorders of the immune system. © 2021 The Royal Society of Chemistry.
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Gold nanoparticles coated with polyvinylpyrrolidone and sea urchin extracellular molecules induce transient immune activation
Alijagic A., Barbero F., Gaglio D., Napodano E., Benada O., Kofroňová O., Puntes V.F., Bastús N.G., Pinsino A. Journal of Hazardous Materials; 402 (123793) 2021. 10.1016/j.jhazmat.2020.123793. IF: 10.588
We report that the immunogenicity of colloidal gold nanoparticles coated with polyvinylpyrrolidone (PVP–AuNPs) in a model organism, the sea urchin Paracentrotus lividus, can function as a proxy for humans for in vitro immunological studies. To profile the immune recognition and interaction from exposure to PVP–AuNPs (1 and 10 μg mL−1), we applied an extensive nano-scale approach, including particle physicochemical characterisation involving immunology, cellular biology, and metabolomics. The interaction between PVP–AuNPs and soluble proteins of the sea urchin physiological coelomic fluid (blood equivalent) results in the formation of a protein “corona” surrounding the NPs from three major proteins that influence the hydrodynamic size and colloidal stability of the particle. At the lower concentration of PVP–AuNPs, the P. lividus phagocytes show a broad metabolic plasticity based on the biosynthesis of metabolites mediating inflammation and phagocytosis. At the higher concentration of PVP–AuNPs, phagocytes activate an immunological response involving Toll-like receptor 4 (TLR4) signalling pathway at 24 hours of exposure. These results emphasise that exposure to PVP–AuNPs drives inflammatory signalling by the phagocytes and the resolution at both the low and high concentrations of the PVP–AuNPs and provides more details regarding the immunogenicity of these NPs. © 2020 Elsevier B.V.
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Growth-promoting gold nanoparticles decrease stress responses in arabidopsis seedlings
Ferrari E., Barbero F., Busquets-Fité M., Franz-Wachtel M., Köhler H.-R., Puntes V., Kemmerling B. Nanomaterials; 11 (12, 3161) 2021. 10.3390/nano11123161. IF: 5.076
The global economic success of man-made nanoscale materials has led to a higher production rate and diversification of emission sources in the environment. For these reasons, novel nanosafety approaches to assess the environmental impact of engineered nanomaterials are required. While studying the potential toxicity of metal nanoparticles (NPs), we realized that gold nanoparticles (AuNPs) have a growth-promoting rather than a stress-inducing effect. In this study we established stable short-and long-term exposition systems for testing plant responses to NPs. Exposure of plants to moderate concentrations of AuNPs resulted in enhanced growth of the plants with longer primary roots, more and longer lateral roots and increased rosette diameter, and reduced oxidative stress responses elicited by the immune-stimulatory PAMP flg22. Our data did not reveal any detri-mental effects of AuNPs on plants but clearly showed positive effects on growth, presumably by their protective influence on oxidative stress responses. Differential transcriptomics and proteomics analyses revealed that oxidative stress responses are downregulated whereas growth-promoting genes/proteins are upregulated. These omics datasets after AuNP exposure can now be exploited to study the underlying molecular mechanisms of AuNP-induced growth-promotion. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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Immunomodulatory function of polyvinylpyrrolidone (Pvp)-functionalized gold nanoparticles in vibrio-stimulated sea urchin immune cells
Alijagic A., Bonura A., Barbero F., Puntes V.F., Gervasi F., Pinsino A. Nanomaterials; 11 (10, 2646) 2021. 10.3390/nano11102646. IF: 5.076
We investigated the role of the gold nanoparticles functionalized with polyvinylpyrrolidone (PVP–AuNPs) on the innate immune response against an acute infection caused by Vibrio anguillarum in an in vitro immunological nonmammalian next-generation model, the sea urchin Paracentrotus lividus. To profile the immunomodulatory function of PVP–AuNPs (0.1 μg mL−1) in sea urchin immune cells stimulated by Vibrio (10 μg mL−1) for 3 h, we focused on the baseline immunological state of the donor, and we analysed the topography, cellular metabolism, and expression of human cell surface antigens of the exposed cells, as well as the signalling leading the interaction between PVP–AuNPs and the Vibrio-stimulated cells. PVP–AuNPs are not able to silence the inflammatory signalling (TLR4/p38MAPK/NF-κB signalling) that involves the whole population of P. lividus immune cells exposed to Vibrio. However, our findings emphasise the ability of PVP–AuNPs to stimulate a subset of rare cells (defined here as Group 3) that express CD45 and CD14 antigens on their surface, which are known to be involved in immune cell maturation and macrophage activation in humans. Our evidence on how PVP–AuNPs may stimulate sea urchin immune cells represents an important starting point for planning new research work on the topic. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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In situ nanoremediation of soils and groundwaters from the nanoparticle's standpoint: A review
Marcon L., Oliveras J., Puntes V.F. Science of the Total Environment; 791 (148324) 2021. 10.1016/j.scitotenv.2021.148324. IF: 7.963
Anthropogenic pollution coming from industrial processes, agricultural practices and consumer products, results in the release of toxic substances into rural and urban environments. Once released, these chemicals migrate through the atmosphere and water, and find their way into matrices such as sediments and groundwaters, thus making large areas potentially uninhabitable. Common pollutants, including heavy metal(loid)s, radionuclides, aliphatic hydrocarbons and halogenated organics, are known to adversely affect physiological systems in animal species. Pollution can be cleaned up using techniques such as coagulation, reverse osmosis, oxidation and biological methods, among others. The use of nanoparticles (NPs) extends the range of available technologies and offers particular benefits, not only by degrading, transforming and immobilizing contaminants, but also by reaching inaccessible areas and promoting biotic degradation. The development of NPs is understandably heralded as an environmentally beneficial technology; however, it is only now that the ecological risks associated with their use are being evaluated. This review presents recent developments in the use of engineered NPs for the in situ remediation of two paramount environmental matrices: soils and groundwaters. Emphasis will be placed on (i) the successful applications of nano-objects for environmental cleanup, (ii) the potential safety implications caused by the challenging requirements of [high reactivity toward pollutants] vs. [none reactivity toward biota], with a thorough view on their transport and evolution in the matrix, and (iii) the perspectives on scientific and regulatory challenges. To this end, the most promising nanomaterials will be considered, including nanoscale zerovalent iron, nano-oxides and carbonaceous materials. The purpose of the present review is to give an overview of the development of nanoremediators since they appeared in the 2000s, from their chemical modifications, mechanism of action and environmental behavior to an understanding of the problematics (technical limitations, economic constraints and institutional precautionary approaches) that will drive their future full-scale applications. © 2021
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Innate Memory Reprogramming by Gold Nanoparticles Depends on the Microbial Agents That Induce Memory
Swartzwelter B.J., Michelini S., Frauenlob T., Barbero F., Verde A., De Luca A.C., Puntes V., Duschl A., Horejs-Hoeck J., Italiani P., Boraschi D. Frontiers in Immunology; 12 (751683) 2021. 10.3389/fimmu.2021.751683. IF: 7.561
Innate immune memory, the ability of innate cells to react in a more protective way to secondary challenges, is induced by exposure to infectious and other exogeous and endogenous agents. Engineered nanoparticles are particulate exogenous agents that, as such, could trigger an inflammatory reaction in monocytes and macrophages and could therefore be also able to induce innate memory. Here, we have evaluated the capacity of engineered gold nanoparticles (AuNPs) to induce a memory response or to modulate the memory responses induced by microbial agents. Microbial agents used were in soluble vs. particulate form (MDP and the gram-positive bacteria Staphylococcus aureus; β-glucan and the β-glucan-producing fungi C. albicans), and as whole microrganisms that were either killed (S. aureus, C. albicans) or viable (the gram-negative bacteria Helicobacter pylori). The memory response was assessed in vitro, by exposing human primary monocytes from 2-7 individual donors to microbial agents with or without AuNPs (primary response), then resting them for 6 days to allow return to baseline, and eventually challenging them with LPS (secondary memory response). Primary and memory responses were tested as production of the innate/inflammatory cytokine TNFα and other inflammatory and anti-inflammatory factors. While inactive on the response induced by soluble microbial stimuli (muramyl dipeptide -MDP-, β-glucan), AuNPs partially reduced the primary response induced by whole microorganisms. AuNPs were also unable to directly induce a memory response but could modulate stimulus-induced memory in a circumscribed fashion, limited to some agents and some cytokines. Thus, the MDP-induced tolerance in terms of TNFα production was further exacerbated by co-priming with AuNPs, resulting in a less inflammatory memory response. Conversely, the H. pylori-induced tolerance was downregulated by AuNPs only relative to the anti-inflammatory cytokine IL-10, which would lead to an overall more inflammatory memory response. These effects of AuNPs may depend on a differential interaction/association between the reactive particle surfaces and the microbial components and agents, which may lead to a change in the exposure profiles. As a general observation, however, the donor-to-donor variability in memory response profiles and reactivity to AuNPs was substantial, suggesting that innate memory depends on the individual history of exposures. © Copyright © 2021 Swartzwelter, Michelini, Frauenlob, Barbero, Verde, De Luca, Puntes, Duschl, Horejs-Hoeck, Italiani and Boraschi.
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Interaction between macrophages and nanoparticles: In vitro 3d cultures for the realistic assessment of inflammatory activation and modulation of innate memory
Swartzwelter B.J., Verde A., Rehak L., Madej M., Puntes V.F., De Luca A.C., Boraschi D., Italiani P. Nanomaterials; 11 (1, 207): 1 - 13. 2021. 10.3390/nano11010207. IF: 5.076
Understanding the modes of interaction between human monocytes/macrophages and engineered nanoparticles is the basis for assessing particle safety, in terms of activation of innate/inflammatory reactions, and their possible exploitation for medical applications. In vitro assessment of nanoparticle-macrophage interaction allows for examining the response of primary human cells, but the conventional 2D cultures do not reproduce the three-dimensional spacing of a tissue and the interaction of macrophages with the extracellular tissue matrix, conditions that shape macrophage recognition capacity and reactivity. Here, we have compared traditional 2D cultures with cultures on a 3D collagen matrix for evaluating the capacity gold nanoparticles to induce monocyte activation and subsequent innate memory in human blood monocytes in comparison to bacterial LPS. Results show that monocytes react to stimuli almost in the same way in 2D and 3D cultures in terms of production of TNFα and IL-6, but that notable differences are found when IL-8 and IL-1Ra are examined, in particular in the recall/memory response of primed cells to a second stimulation, with the 3D cultures showing cell activation and memory effects of nanoparticles better. In addition, the response variations in monocytes/macrophages from different donors point towards a personalized assessment of the nanoparticle effects on macrophage activation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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Interaction of nanoparticles with endotoxin Importance in nanosafety testing and exploitation for endotoxin binding
Mangini M., Verde A., Boraschi D., Puntes V.F., Italiani P., De Luca A.C. Nanotoxicology; 15 (4): 558 - 576. 2021. 10.1080/17435390.2021.1898690. IF: 5.913
The interaction between engineered nanoparticles and the bacterial lipopolysaccharide, or endotoxin, is an event that warrants attention. Endotoxin is one of the most potent stimulators of inflammation and immune reactions in human beings, and is a very common contaminant in research labs. In nanotoxicology and nanomedicine, the presence of endotoxin on the nanoparticle surface affects their biological properties leading to misinterpretation of results. This review discusses the importance of detecting the endotoxin contamination on nanoparticles, focusing on the current method of endotoxin detection and their suitability for nanoparticulate materials. Conversely, the capacity of nanoparticles to bind endotoxin can be enhanced by functionalization with endotoxin-capturing molecules, opening the way to the development of novel endotoxin detection assays. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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Introducing visible-light sensitivity into photocatalytic CeO2nanoparticles by hybrid particle preparation exploiting plasmonic properties of gold: Enhanced photoelectrocatalysis exemplified for hydrogen peroxide sensing
Zhao S., Riedel M., Patarroyo J., Bastus N., Puntes V., Yue Z., Lisdat F., Parak W.J. Nanoscale; 13 (2): 980 - 990. 2021. 10.1039/d0nr06356h. IF: 7.790
In this report we combine the catalytic properties of CeO2 nanoparticles with their transduction ability for photoelectrochemical sensing. This study highlights the usage of CeO2 providing catalytic activity towards H2O2, but only with a limited excitation range in the UV for the construction of a sensing system. In order to improve the photoelectrocatalysis of CeO2 nanoparticles by extending their excitation to visible light, Au/CeO2 core/shell hybrid nanoparticles have been synthesized. The hybrid nanoparticles are fixed on electrodes, allowing for the generation of photocurrents, the direction of which can be controlled by the electrode potential (without bias). The application of the hybrid nanoparticles results in an enhanced photocurrent amplitude under white light illumination as compared to the pure CeO2 nanoparticles. Wavelength-dependent measurements confirm the participation of the Au core in the signal transduction. This can be explained by improved charge carrier generation within the hybrid particles. Thus, by using a plasmonic element the photoelectochemical response of a catalytic nanoparticle (i.e. CeO2) has been spectrally extended. The effect can be exploited for sensorial hydrogen peroxide detection. Here higher photocatalytic current responses have been found for the hybrid particles fixed to gold electrodes although the catalytic reduction has been comparable for both types of nanoparticles. Thus, it can be demonstrated that Au/CeO2 core-shell nanoparticles allow the utilization of visible light for photoelectrochemical hydrogen peroxide (H2O2) detection with improved sensitivity under white light illumination or application of such particles with only visible light excitation, which is not possible for pure CeO2. With help of the layer-by-layer (LbL) technique for nanoparticle immobilization, the electrode response can be adjusted and with a 5 layers electrode a low detection limit of about 3 μM H2O2 with a linear detection range up to 2000 μM is obtained. This journal is © The Royal Society of Chemistry.
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Mesoporous silica coated CeO2nanozymes with combined lipid-lowering and antioxidant activity induce long-term improvement of the metabolic profile in obese Zucker rats
Parra-Robert M., Zeng M., Shu Y., Fernández-Varo G., Perramón M., Desai D., Chen J., Guo D., Zhang X., Morales-Ruiz M., Rosenholm J.M., Jiménez W., Puntes V., Casals E., Casals G. Nanoscale; 13 (18): 8452 - 8466. 2021. 10.1039/d1nr00790d. IF: 7.790
Obesity is one of the most important public health problems that is associated with an array of metabolic disorders linked to cardiovascular disease, stroke, type 2 diabetes, and cancer. A sustained therapeutic approach to stop the escalating prevalence of obesity and its associated metabolic comorbidities remains elusive. Herein, we developed a novel nanocomposite based on mesoporous silica coated cerium oxide (CeO2) nanozymes that reduce the circulating levels of fatty acids and remarkably improve the metabolic phenotype in a model of obese Zucker rats five weeks after its administration. Lipidomic and gene expression analyses showed an amelioration of the hyperlipidemia and of the hepatic and adipose metabolic dysregulations, which was associated with a down-regulation of the hepatic PI3K/mTOR/AKT pathway and a reduction of the M1 proinflammatory cytokine TNF-a. In addition, the coating of the CeO2 maximized its cell antioxidant protective effects and minimized non-hepatic biodistribution. The one-pot synthesis method for the nanocomposite fabrication is implemented entirely in aqueous solution, room temperature and open atmosphere conditions, favoring scalability and offering a safe and translatable lipid-lowering and antioxidant nanomedicine to treat metabolic comorbidities associated with obesity. This approach may be further applied to address other metabolic disorders related to hyperlipidemia, low-grade inflammation and oxidative stress. © 2021 The Royal Society of Chemistry.
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Microfluidic In Vitro Platform for (Nano)Safety and (Nano)Drug Efficiency Screening
Kohl Y., Biehl M., Spring S., Hesler M., Ogourtsov V., Todorovic M., Owen J., Elje E., Kopecka K., Moriones O.H., Bastús N.G., Simon P., Dubaj T., Rundén-Pran E., Puntes V., William N., von Briesen H., Wagner S., Kapur N., Mariussen E., Nelson A., Gabelova A., Dusinska M., Velten T., Knoll T. Small; 17 (15, 2006012) 2021. 10.1002/smll.202006012. IF: 13.281
Microfluidic technology is a valuable tool for realizing more in vitro models capturing cellular and organ level responses for rapid and animal-free risk assessment of new chemicals and drugs. Microfluidic cell-based devices allow high-throughput screening and flexible automation while lowering costs and reagent consumption due to their miniaturization. There is a growing need for faster and animal-free approaches for drug development and safety assessment of chemicals (Registration, Evaluation, Authorisation and Restriction of Chemical Substances, REACH). The work presented describes a microfluidic platform for in vivo-like in vitro cell cultivation. It is equipped with a wafer-based silicon chip including integrated electrodes and a microcavity. A proof-of-concept using different relevant cell models shows its suitability for label-free assessment of cytotoxic effects. A miniaturized microscope within each module monitors cell morphology and proliferation. Electrodes integrated in the microfluidic channels allow the noninvasive monitoring of barrier integrity followed by a label-free assessment of cytotoxic effects. Each microfluidic cell cultivation module can be operated individually or be interconnected in a flexible way. The interconnection of the different modules aims at simulation of the whole-body exposure and response and can contribute to the replacement of animal testing in risk assessment studies in compliance with the 3Rs to replace, reduce, and refine animal experiments. © 2021 The Authors. Small published by Wiley-VCH GmbH
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Pharmacokinetics, biodistribution, and biosafety of pegylated gold nanoparticles in vivo
Kozics K., Sramkova M., Kopecka K., Begerova P., Manova A., Krivosikova Z., Sevcikova Z., Liskova A., Rollerova E., Dubaj T., Puntes V., Wsolova L., Simon P., Tulinska J., Gabelova A. Nanomaterials; 11 (7, 1702) 2021. 10.3390/nano11071702. IF: 5.076
Despite the obvious advantages of gold nanoparticles for biomedical applications, controversial and incomplete toxicological data hamper their widespread use. Here, we present the results from an in vivo toxicity study using gold nanoparticles coated with polyethylene glycol (PEG-AuNPs). The pharmacokinetics and biodistribution of PEG-AuNPs were examined in the rat’s liver, lung, spleen, and kidney after a single i.v. injection (0.7 mg/kg) at different time intervals. PEG-AuNPs had a relatively long blood circulation time and accumulated primarily in the liver and spleen, where they remained for up to 28 days after administration. Increased cytoplasmic vacuolation in hepatocytes 24 h and 7 days after PEG-AuNPs exposure and apoptotic-like cells in white splenic pulp 24 h after administration has been detected, however, 28 days post-exposure were no longer observed. In contrast, at this time point, we identified significant changes in lipid metabolism, altered levels of liver injury markers, and elevated monocyte count, but without marked biological relevance. In blood cells, no DNA damage was present in any of the studied time intervals, with the exception of DNA breakage transiently detected in primary kidney cells 4 h post-injection. Our results indicate that the tissue accumulation of PEG-AuNPs might result in late toxic effects. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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Preclinical studies conducted on nanozyme antioxidants: Shortcomings and challenges based on US FDA regulations
Ghorbani M., Izadi Z., Jafari S., Casals E., Rezaei F., Aliabadi A., Moore A., Ansari A., Puntes V., Jaymand M., Derakhshankhah H. Nanomedicine; 16 (13): 1133 - 1151. 2021. 10.2217/nnm-2021-0030. IF: 5.307
The wide prevalence of oxidative stress-induced diseases has led to a growing demand for antioxidant therapeutics worldwide. Nanozyme antioxidants are drawing enormous attention as practical alternatives for conventional antioxidants. The considerable body of research over the last decade and the promising results achieved signify the potential of nanozyme antioxidants to secure a place in the expanding market of antioxidant therapeutics. Nonetheless, there is no report on clinical trials for their further evaluation. Through analyzing in-depth selected papers which have conducted in vivo studies on nanozyme antioxidants, this review aims to pinpoint and discuss possible reasons impeding development of research toward clinical studies and to offer some practical solutions for future studies to bridge the gap between preclinical and clinical stages. "We did not experience these kinds of strange illnesses in the past." Everybody might have heard such a familiar sentence from their grandparents and asked themselves, why? The current paper aims to provide readers with one of the answers: "Oxidative stress", which happens when the body fails to neutralize damage caused by unstable molecules called free radicals. In this paper, the authors present the seriousness of oxidative stress-induced clinical conditions. They discuss one of the promising treatments, nanozyme antioxidants, these are mostly based on nano-sized materials with enzyme-like function, in other words, they can speed up chemical reactions. Despite significant results, nanozyme antioxidants have not been investigated in clinical studies. This paper intends to search for the main reasons for this and suggest possible solutions. © 2021 Future Medicine Ltd. © 2021 Future Medicine Ltd.. All rights reserved.
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Scalable synthesis of multicomponent multifunctional inorganic core@mesoporous silica shell nanocomposites
Zeng M., Shu Y., Parra-Robert M., Desai D., Zhou H., Li Q., Rong Z., Karaman D.Ş., Yang H., Peng J., Fernandez-Varo G., Jiménez W., Casals G., Puntes V., Rosenholm J.M., Casals E. Materials science & engineering. C, Materials for biological applications; 128: 112272. 2021. 10.1016/j.msec.2021.112272. IF: 7.328
Integrating multiple materials with different functionalities in a single nanostructure enables advances in many scientific and technological applications. However, such highly sophisticated nanomaterials usually require complex synthesis processes that complicate their preparation in a sustainable and industrially feasible manner. Herein, we designed a simple general method to grow a mesoporous silica shell onto any combination of hydrophilic nanoparticle cores. The synthetic strategy, based on the adjustment of the key parameters of the sol-gel process for the silica shell formation, allows for the embedment of single, double, and triple inorganic nanoparticles within the same shell, as well as the size-control of the obtained nanocomposites. No additional interfacial adhesive layer is required on the nanoparticle surfaces for the embedding process. Adopting this approach, electrostatically stabilized, small-sized (from 4 to 15 nm) CeO2, Fe3O4, Gd2O3, NaYF4, Au, and Ag cores were used to test the methodology. The mean diameter of the resulting nanocomposites could be as low as 55 nm, with high monodispersity. These are very feasible sizes for biological intervention, and we further observed increased nanoparticle stability in physiological environments. As a demonstration of their increased activity as a result of this, the antioxidant activity of CeO2 cores was enhanced when in core-shell form. Remarkably, the method is conducted entirely at room temperature, atmospheric conditions, and in aqueous solvent with the use of ethanol as co-solvent. These facile and even "green" synthesis conditions favor scalability and easy preparation of multicomponent nanocomposite libraries with standard laboratory glassware and simple benchtop chemistry, through this sustainable and cost-effective fabrication process. Copyright © 2021 Elsevier B.V. All rights reserved.
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Stressor‐dependant changes in immune parameters in the terrestrial isopod crustacean, porcellio scaber: A focus on nanomaterials
Mayall C., Dolar A., Kokalj A.J., Novak S., Razinger J., Barbero F., Puntes V., Drobne D. Nanomaterials; 11 (4, 934) 2021. 10.3390/nano11040934. IF: 5.076
We compared the changes of selected immune parameters of Porcellio scaber to different stressors. The animals were either fed for two weeks with Au nanoparticles (NPs), CeO2 NPs, or Au ions or body‐injected with Au NPs, CeO2 NPs, or lipopolysaccharide endotoxin. Contrary to expec-tations, the feeding experiment showed that both NPs caused a significant increase in the total hae-mocyte count (THC). In contrast, the ion‐positive control resulted in a significantly decreased THC. Additionally, changes in phenoloxidase (PO)‐like activity, haemocyte viability, and nitric oxide (NO) levels seemed to depend on the stressor. Injection experiments also showed stressor‐depend-ant changes in measured parameters, such as CeO2 NPs and lipopolysaccharide endotoxin (LPS), caused more significant responses than Au NPs. These results show that feeding and injection of NPs caused an immune response and that the response differed significantly, depending on the exposure route. We did not expect the response to ingested NPs, due to the low exposure concentrations (100 μg/g dry weight food) and a firm gut epithelia, along with a lack of phagocytosis in the digestive system, which would theoretically prevent NPs from crossing the biological barrier. It remains a challenge for future research to reveal what the physiological and ecological significance is for the organism to sense and respond, via the immune system, to ingested foreign material. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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Sustained effect of zero-valent iron nanoparticles under semi-continuous anaerobic digestion of sewage sludge: Evolution of nanoparticles and microbial community dynamics
Barrena R., Vargas-García M.D.C., Capell G., Barańska M., Puntes V., Moral-Vico J., Sánchez A., Font X. Science of the Total Environment; 777 (145969) 2021. 10.1016/j.scitotenv.2021.145969. IF: 7.963
The effects of adding zero-valent iron nanoparticles (nZVI) on the physicochemical, biological and biochemical responses of a semi-continuous anaerobic digestion of sewage sludge have been assessed. Two sets of consecutive experiments of 103 and 116 days, respectively, were carried out in triplicate. nZVI were magnetically retained in the reactors, and the effect of punctual doses (from 0.27 to 4.33 g L−1) over time was studied. Among the different parameters monitored, only methane content in the biogas was significantly higher when nZVI was added. However, this effect was progressively lost after the addition, and in 5–7 days, the methane content returned to initial values. The increase in the oxidation state of nanoparticles seems to be related to the loss of effect over time. Higher dose (4.33 g L−1) sustained positive effects for a longer time along with higher methane content, but this fact seems to be related to microbiome acclimation. Changes in microbial community structure could also play a role in the mechanisms involved in methane enhancement. In this sense, the microbial consortium analysis reported a shift in the balance among acetogenic eubacterial communities, and a marked increase in the relative abundance of members assigned to Methanothrix genus, recognized as acetoclastic species showing high affinity for acetate, which explain the rise in methane content in the biogas. This research demonstrates that biogas methane enrichment in semicontinuous anaerobic digesters can be achieved by using nZVI nanoparticles, thus increasing energy production or reducing costs of a later biogas upgrading process. © 2021 Elsevier B.V.
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The interactions between nanoparticles and the innate immune system from a nanotechnologist perspective
Ernst L.M., Casals E., Italiani P., Boraschi D., Puntes V. Nanomaterials; 11 (11, 2991) 2021. 10.3390/nano11112991. IF: 5.076
The immune system contributes to maintaining the body’s functional integrity through its two main functions: recognizing and destroying foreign external agents (invading microorganisms) and identifying and eliminating senescent cells and damaged or abnormal endogenous entities (such as cellular debris or misfolded/degraded proteins). Accordingly, the immune system can detect molecular and cellular structures with a spatial resolution of a few nm, which allows for detecting molecular patterns expressed in a great variety of pathogens, including viral and bacterial proteins and bacterial nucleic acid sequences. Such patterns are also expressed in abnormal cells. In this context, it is expected that nanostructured materials in the size range of proteins, protein aggregates, and viruses with different molecular coatings can engage in a sophisticated interaction with the immune system. Nanoparticles can be recognized or passed undetected by the immune system. Once detected, they can be tolerated or induce defensive (inflammatory) or anti-inflammatory responses. This paper describes the different modes of interaction between nanoparticles, especially inorganic nanoparticles, and the immune system, especially the innate immune system. This perspective should help to propose a set of selection rules for nanosafety-by-design and medical nanoparticle design. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
