Adenosine monophosphate is elevated in the bronchoalveolar lavage fluid of mice with acute respiratory toxicity induced by nanoparticles with high surface hydrophobicity

Beyond the promise: Exploring the complex interactions of nanoparticles within biological systems

The exploration of nanoparticle applications is filled with promise, but their impact on the environment and human health raises growing concerns. These tiny environmental particles can enter the human body through various routes, such as the respiratory system, digestive tract, skin absorption, intravenous injection, and implantation. Once inside, they can travel to distant organs via the bloodstream and lymphatic system. This journey often results in nanoparticles adhering to cell surfaces and being internalized. Upon entering cells, nanoparticles can provoke significant structural and functional changes. They can potentially disrupt critical cellular processes, including damaging cell membranes and cytoskeletons, impairing mitochondrial function, altering nuclear structures, and inhibiting ion channels. These disruptions can lead to widespread alterations by interfering with complex cellular signaling pathways, potentially causing cellular, organ, and systemic impairments. This article delves into the factors influencing how nanoparticles behave in biological systems. These factors include the nanoparticles' size, shape, charge, and chemical composition, as well as the characteristics of the cells and their surrounding environment. It also provides an overview of the impact of nanoparticles on cells, organs, and physiological systems and discusses possible mechanisms behind these adverse effects. Understanding the toxic effects of nanoparticles on physiological systems is crucial for developing safer, more effective nanoparticle-based technologies.

Effects of Workers Exposure to Nanoparticles Studied by NMR Metabolomics

In this study, the effects of occupational exposure to nanoparticles (NPs) were studied by NMR metabolomics. Exhaled breath condensate (EBC) and blood plasma samples were obtained from a research nanoparticles-processing unit at a national research university. The samples were taken from three groups of subjects: samples from workers exposed to nanoparticles collected before and after shift, and from controls not exposed to NPs. Altogether, 60 1H NMR spectra of exhaled breath condensate (EBC) samples and 60 1H NMR spectra of blood plasma samples were analysed, 20 in each group. The metabolites identified together with binning data were subjected to multivariate statistical analysis, which provided clear discrimination of the groups studied. Statistically significant metabolites responsible for group separation served as a foundation for analysis of impaired metabolic pathways. It was found that the acute effect of NPs exposure is mainly reflected in the pathways related to the production of antioxidants and other protective species, while the chronic effect is manifested mainly in the alteration of glutamine and glutamate metabolism, and the purine metabolism pathway.

Fast and Robust Proteome Screening Platform Identifies Neutrophil Extracellular Trap Formation in the Lung in Response to Cobalt Ferrite Nanoparticles

Despite broad application of magnetic nanoparticles in biomedicine and electronics, only a few in vivo studies on biocompatibility are available. In this study, toxicity of magnetic metal oxide nanoparticles on the respiratory system was examined in vivo by single intratracheal instillation in mice. Bronchoalveolar lavage fluid (BALF) samples were collected for proteome analyses by LC-MS/MS, testing Fe₃O₄ nanoparticles doped with increasing amounts of cobalt (Fe₃O₄, CoFe₂O₄ with an iron to cobalt ratio 5:1, 3:1, 1:3, Co₃O₄) at two doses (54 μg, 162 μg per animal) and two time points (day 1 and 3 days postinstillation). In discovery phase, in-depth proteome profiling of a few representative samples allowed for comprehensive pathway analyses. Clustering of the 681 differentially expressed proteins (FDR < 0.05) revealed general as well as metal oxide specific responses with an overall strong induction of innate immunity and activation of the complement system. The highest expression increase could be found for a cluster of 39 proteins, which displayed strong dose-dependency to iron oxide and can be attributed to neutrophil extracellular trap (NET) formation. In-depth proteome analysis expanded the knowledge of in vivo NET formation. During screening, all BALF samples of the study (n = 166) were measured label-free as single-injections after a short gradient (21 min) LC separation using the Evosep One system, validating the findings from the discovery and defining protein signatures which enable discrimination of lung inflammation. We demonstrate a proteomics-based toxicity screening with high sample throughput easily transferrable to other nanoparticle types. Data are available via ProteomeXchange with identifier PXD016148.

Cytotoxicity-Related Bioeffects Induced by Nanoparticles: The Role of Surface Chemistry

Nanoparticles (NPs) are widely used in a variety of fields, including those related to consumer products, architecture, energy, and biomedicine. Once they enter the human body, NPs contact proteins in the blood and interact with cells in organs, which may induce cytotoxicity. Among the various factors of NP surface chemistry, surface charges, hydrophobicity levels and combinatorial decorations are found to play key roles inregulating typical cytotoxicity-related bioeffects, including protein binding, cellular uptake, oxidative stress, autophagy, inflammation, and apoptosis. In this review, we summarize the recent progress made in directing the levels and molecular pathways of these cytotoxicity-related effects by the purposeful design of NP surface charge, hydrophobicity, and combinatorial decorations.

Gustav Born: pioneer in imaging platelet and leukocyte biology

Gustav Born achieved scientific fame for his application of light transmission aggregometry to the study of platelet function, but also led interdisciplinary research teams in pioneering quantitative in vivo imaging studies of platelet aggregation and leukocyte adhesion, and in conducting the first research into the biomechanical factors underlying atherosclerotic plaque rupture. Gus Born also communicated both current research findings and an integrated understanding of cardiovascular biology to a wide audience through acting as scientific advisor on several television productions. Using footage from two of these films, we discuss Gustav Born's scientific achievements and legacy.

Lung Protection Strategies during Cardiopulmonary Bypass Affect the Composition of Bronchoalveolar Fluid and Lung Tissue in Cardiac Surgery Patients

Pulmonary dysfunction is among the most frequent complications to cardiac surgeries. Exposure of blood to the cardiopulmonary bypass (CPB) circuit with subsequent lung ischemia-reperfusion leads to the production of inflammatory mediators and increases in microvascular permeability. The study aimed to elucidate histological, cellular, and metabolite changes following two lung protective regimens during CPB with Histidine-Tryptophan-Ketoglutarate (HTK) enriched or warm oxygenated blood pulmonary perfusion compared to standard regimen with no pulmonary perfusion. A total of 90 patients undergoing CPB were randomized to receiving HTK, oxygenated blood or standard regimen. Of these, bronchoalveolar lavage fluid (BALF) and lung tissue biopsies were obtained before and after CPB from 47 and 25 patients, respectively. Histopathological scores, BALF cell counts and metabolite screening were assessed. Multivariate and univariate analyses were performed. Profound histological, cellular, and metabolic changes were identified in all patients after CPB. Histological and cellular changes were similar in the three groups; however, some metabolite profiles were different in the HTK patients. While all patients presented an increase in inflammatory cells, metabolic acidosis, protease activity and oxidative stress, HTK patients seemed to be protected against severe acidosis, excessive fatty acid oxidation, and inflammation during ischemia-reperfusion. Additional studies are needed to confirm these findings.

A prototypic small molecule database for bronchoalveolar lavage-based metabolomics

The analysis of bronchoalveolar lavage fluid (BALF) using mass spectrometry-based metabolomics can provide insight into lung diseases, such as asthma. However, the important step of compound identification is hindered by the lack of a small molecule database that is specific for BALF. Here we describe prototypic, small molecule databases derived from human BALF samples (n=117). Human BALF was extracted into lipid and aqueous fractions and analyzed using liquid chromatography mass spectrometry. Following filtering to reduce contaminants and artifacts, the resulting BALF databases (BALF-DBs) contain 11,736 lipid and 658 aqueous compounds. Over 10% of these were found in 100% of samples. Testing the BALF-DBs using nested test sets produced a 99% match rate for lipids and 47% match rate for aqueous molecules. Searching an independent dataset resulted in 45% matching to the lipid BALF-DB compared to<25% when general databases are searched. The BALF-DBs are available for download from MetaboLights. Overall, the BALF-DBs can reduce false positives and improve confidence in compound identification compared to when general databases are used.

Absence of lung fibrosis after a single pulmonary delivery of lipid nanocapsules in rats

Lipid nanocapsules (LNCs) are potential drug carriers for pulmonary delivery since they can be nebulized without any structural or functional changes, and the aerosols produced are highly compatible with pulmonary drug delivery in human beings. The alveolar surface tension, in vitro cytotoxicity, biodistribution and pulmonary toxicity in rats of a single endotracheal spray of LNCs or paclitaxel-loaded LNCs were studied. In vitro cytotoxicity of LNCs after a spray remained unchanged. Biodistribution study showed a homogeneous repartition in the lungs in rats with an improvement in lung retention of the radiolabeled tracer loaded in LNCs compared to the absence of LNCs with a lung half-time of 8.8±0.7 hours. Bronchoalveolar fluid analysis revealed transient 7-day alveolar inflammation, reaching a maximum between days 2 and 4, characterized by a peak of granulocytes at day 1 followed by a peak of lymphocytes at day 3. Alveolar protein levels were increased at days 3 and 7. Acute inflammation was increased with paclitaxel-loaded LNCs in comparison with blank LNCs but dropped out at day 7. No histological pulmonary lesion was observed at day 60. LNCs lowered surface tension to a greater degree than Curosurf^® in a physicochemical model of the pulmonary alveolus. A single pulmonary delivery of LNCs induces a short-term alveolar inflammation with no residual lesions in rats at day 60. These data permit to start the study of LNCs in surfactant replacement therapy.

Role of omics techniques in the toxicity testing of nanoparticles

Nanotechnology is regarded as a key technology of the twenty-first century. Despite the many advantages of nanotechnology it is also known that engineered nanoparticles (NPs) may cause adverse health effects in humans. Reports on toxic effects of NPs relay mainly on conventional (phenotypic) testing but studies of changes in epigenome, transcriptome, proteome, and metabolome induced by NPs have also been performed. NPs most relevant for human exposure in consumer, health and food products are metal, metal oxide and carbon-based NPs. They were also studied quite frequently with omics technologies and an overview of the study results can serve to answer the question if screening for established targets of nanotoxicity (e.g. cell death, proliferation, oxidative stress, and inflammation) is sufficient or if omics techniques are needed to reveal new targets. Regulated pathways identified by omics techniques were confirmed by phenotypic assays performed in the same study and comparison of particle types and cells by the same group indicated a more cell/organ-specific than particle specific regulation pattern. Between different studies moderate overlap of the regulated pathways was observed and cell-specific regulation is less obvious. The lack of standardization in particle exposure, in omics technologies, difficulties to translate mechanistic data to phenotypes and comparison with human in vivo data currently limit the use of these technologies in the prediction of toxic effects by NPs.

Unveiling the Molecular Structure of Pulmonary Surfactant Corona on Nanoparticles

The growing risk of human exposure to airborne nanoparticles (NPs) causes a general concern on the biosafety of nanotechnology. Inhaled NPs can deposit in the deep lung at which they interact with the pulmonary surfactant (PS). Despite the increasing study of nano-bio interactions, detailed molecular mechanisms by which inhaled NPs interact with the natural PS system remain unclear. Using coarse-grained molecular dynamics simulation, we studied the interaction between NPs and the PS system in the alveolar fluid. It was found that regardless of different physicochemical properties, upon contacting the PS, both silver and polystyrene NPs are immediately coated with a biomolecular corona that consists of both lipids and proteins. Structure and molecular conformation of the PS corona depend on the hydrophobicity of the pristine NPs. Quantitative analysis revealed that lipid composition of the corona formed on different NPs is relatively conserved and is similar to that of the bulk phase PS. However, relative abundance of the surfactant-associated proteins, SP-A, SP-B, and SP-C, is notably affected by the hydrophobicity of the NP. The PS corona provides the NPs with a physicochemical barrier against the environment, equalizes the hydrophobicity of the pristine NPs, and may enhance biorecognition of the NPs. These modifications in physicochemical properties may play a crucial role in affecting the biological identity of the NPs and hence alter their subsequent interactions with cells and other biological entities. Our results suggest that all studies of inhalation nanotoxicology or NP-based pulmonary drug delivery should consider the influence of the PS corona.

Systems Biology to Support Nanomaterial Grouping

The assessment of potential health risks of engineered nanomaterials (ENMs) is a challenging task due to the high number and great variety of already existing and newly emerging ENMs. Reliable grouping or categorization of ENMs with respect to hazards could help to facilitate prioritization and decision making for regulatory purposes. The development of grouping criteria, however, requires a broad and comprehensive data basis. A promising platform addressing this challenge is the systems biology approach. The different areas of systems biology, most prominently transcriptomics, proteomics and metabolomics, each of which provide a wealth of data that can be used to reveal novel biomarkers and biological pathways involved in the mode-of-action of ENMs. Combining such data with classical toxicological data would enable a more comprehensive understanding and hence might lead to more powerful and reliable prediction models. Physico-chemical data provide crucial information on the ENMs and need to be integrated, too. Overall statistical analysis should reveal robust grouping and categorization criteria and may ultimately help to identify meaningful biomarkers and biological pathways that sufficiently characterize the corresponding ENM subgroups. This chapter aims to give an overview on the different systems biology technologies and their current applications in the field of nanotoxicology, as well as to identify the existing challenges.

Interactions of stealth conjugated polymer nanoparticles with human whole blood

Photoluminescent conjugated polymeric nanoparticles (CPNs) exhibit favourable properties as fluorescent probes due to their brightness, high photostability, tunable emission spectra and ease of surface modification.