To Örebro University

Titanium dioxide nanoparticles (TiO₂NPs) are widely produced engineered nanomaterials with ongoing human exposure through consumer and occupational uses. Conventional in vitro assays often focus on cytotoxicity and may therefore overlook early or sublethal cellular perturbations. Here, we applied Cell Painting-based phenomics to resolve size-dependent sub-lethal phenotypic signatures of TiO2NP exposure in human HepG2 hepatocytes. Two TiO2NPs (<25 nm and <100 nm) were characterized by field emission scanning electron microscopy and evaluated following 24-hour exposure at five concentrations: 6.25, 12.5, 25, 50, and 100 µg/mL. Cell viability was assessed using the alamarBlue assay, and high-dimensional phenotypic profiles were generated using Cell Painting-based phenomics, including automated high-content imaging and CellProfiler-based feature extraction. TiO2NP exposure induced modest reductions in viability at the highest concentration, indicating limited acute cytotoxicity. In contrast, phenomic profiling revealed clear, concentration-dependent phenotypic perturbations for both size fractions, with markedly stronger and more consistent effects for the < 100 nm TiO2NPs. At 100 µg/mL, the < 100 nm TiO2NPs altered 50.9% of the measured phenotypic features, compared with 28.9% for the < 25 nm particles, with prominent contributions from endoplasmic reticulum-, actin/Golgi/plasma membrane-, mitochondria-, and RNA-associated features. Dimensionality reduction and correlation analyses confirmed reproducible, concentration-dependent phenotypic trajectories. Importantly, the TiO2NP-induced phenotypes were distinct from those induced by the reference chemical CA-074Me, which produced broad perturbations and served as a reference chemical to verify assay sensitivity and dynamic range. Overall, Cell Painting phenomics sensitively captures size-dependent, sublethal cellular phenotypes induced by TiO2NPs, supporting its value as a New Approach Methodology for nanosafety assessment beyond conventional viability endpoints.

Metal additive manufacturing (AM) relies on alloy feedstock powders that may come into contact with the workers' skin during handling, yet skin-relevant data on metal release and biological reactivity remain limited. Here, we assessed the cutaneous bioactivity of the fine particle fraction of four gas-atomized Fe-based AM powders (316L stainless steel, Fe-powder A, and tooling steels B and C). Powders were sieved to <10 mu m and characterized by scanning electron microscopy and X-ray photoelectron spectroscopy before and after incubation in artificial sweat (ASW). Metal biodissolution was quantified in ASW and keratinocyte culture medium using atomic absorption spectrophotometry. Cellular responses were evaluated in HaCaT keratinocytes using Cell Painting-based phenomics and multiplex cytokine/chemokine profiling and in an ex vivo full-thickness human skin explant model, including superficial barrier disruption, IL-8/CXCL8 quantification, and histological assessment. ASW exposure induced marked shifts in the outermost surface composition across powders, indicating sweat-driven surface transformation. Biodissolution was low and medium-dependent, with Fe dominating the release in ASW, and with an overall metal release remaining limited in cell culture medium. In HaCaT cells, MCP-1/CCL2, IL-6, and IL-8/CXCL8 were quantifiable but showed no significant changes following powder exposure. Cell Painting revealed subtle, shared phenotypic signatures, primarily involving mitochondrial-associated features, without evidence of broad cellular stress. In the ex vivo skin model, AM powders did not increase IL-8/CXCL8 secretion, the particles remained localized to the skin surface without detectable penetration, and coexposure with Staphylococcus epidermidis did not enhance bacterial colonization or induce inflammation. To the best of our knowledge, this is the first study that applies a human skin explant model to evaluate dermal responses to metal AM powders. Overall, the tested AM powders showed low short-term cutaneous reactivity under skin-relevant conditions, providing human-relevant evidence to inform occupational risk assessment in AM environments.

The host immune response in sepsis involves both pro- and anti-inflammatory mechanisms, with monocytes playing a central role in the process. We have previously identified an in vitro response profile of endotoxin (LPS) tolerant primary human monocytes, consisting of eight cytokines/chemokines as well as a set of five transcription factors. In the current study, we evaluated differences in expression levels of these investigated molecular markers across different patient groups (patients with or without infection, and with or without sepsis), and their association with clinical outcomes (septic shock and in-hospital mortality), among 809 ambulance patients. The results showed that patients with sepsis displayed the lowest HLA-DRA expression levels together with the lowest TNF/IL-10 ratio, while most other cytokine/chemokines and gene expressions were elevated. Higher levels of HGF, CCL8, CCL2, TNF and IL-10, as well as upregulation of HIF1A and NFKBIA were seen in septic patients with septic shock. The data suggests that the investigated immunological markers linked to immunosuppressed monocyte responses are associated with patients with sepsis and septic shock.

BACKGROUND & AIMS: To investigate the role of surgical technique - OPEN or minimally invasive surgery (MIS) - on the development of postoperative insulin resistance and inflammatory response in elective colorectal resections for cancer.

METHODS: Clinical exploratory study of patients with colorectal cancer planned for elective colorectal resections by either OPEN (n = 8) or MIS (n = 9) approach within a controlled Enhanced Recovery After Surgery (ERAS) program. Insulin sensitivity was determined using the hyperinsulinemic normoglycemic clamp and blood samples were collected before and after surgery for analysis of glucose, hormones and inflammatory markers in both the OPEN and MIS group, as well as comparing the two groups to each other.

RESULTS: Patients undergoing surgery, OPEN or MIS, exhibited postoperative insulin resistance to a similar degree regardless of surgical approach. Postoperative plasma levels of the inflammatory markers CRP and IL-6 were significantly (p < 0.05) higher following open surgery. Perioperative compliance to the ERAS protocol was similar in both the OPEN and MIS groups.

CONCLUSION: While open colorectal surgery did elicit a significantly higher inflammatory response compared to MIS, the surgical approach did not influence the degree of postoperative insulin resistance in patients undergoing colorectal resections for cancer in ERAS.

Background: Meningococcal disease is caused by the bacterium Neisseria meningitidis, which is a commensal in the human upper airways. Teenagers and young adults are the main reservoir for the bacteria. The aim of this study was to assess the prevalence of meningococcal carriage and risk factors for carriage among high school and university students in Northwestern Ethiopia.

Methods: Oropharyngeal swabs and buccal samples were collected and stored on Whatman FTA-cards pending PCR analysis. DNA was extracted and a Multiplex TaqMan® custom assay was performed to detect N. meningitidis bacteria using the genes sodC and porA as species-specific targets. Genogrouping was performed for the samples positive for N. meningitidis using multiplex real-time PCR for the groups A, B, C, W, Y and X using a Rotor-Gene Q real-time PCR system.

Result: Out of the 1025 participants, 52% were female with a mean and median ages of 17 and 16 years, respectively. A total of 19 throat swab samples were positive for N. meningitidis giving an overall carriage rate of 1.9%. The carriage rate of N. meningitidis among high school students was 1.0% and 2.5% for the University students, respectively (p-value = 0.051). A significantly higher carriage rate was observed among participants with the age of 23 and above (p-value = 0.021). Among the N. meningitidis isolates, 16 out of 19 were non-groupable, while 3 were groupable. Of the groupable isolates, two belonged to group W and one to group B. Among the risk factors assessed, sharing a glass or bottle for drinking (86%), not having received a meningitis vaccine (66%), and having had a tonsillectomy (47%), were the most common risk factors. Among participants with positive meningococcal carriage, 89% of them have shared glass for drinking and 74% of them had not received previous meningococcal vaccine, while this figure is reduced to 66% and 65%, respectively among the non-carriers.

Conclusion: The overall meningococcal carriage rate was lower than those reported in previous Ethiopian studies, with age as the only identified risk factor.

Background: Respirable crystalline silica (RCS) is a well-established occupational health hazard. Inflammation and oxidative stress are key mechanisms for diseases associated with exposure; however, the role of lipid inflammatory mediators remains unclear. Oxylipins, a diverse group of lipid mediators derived mainly from arachidonic acid or linoleic acid via cyclooxygenases, lipoxygenases or P450 enzymes may contribute to silica-induced pathology. This study investigates the association between RCS exposure and oxylipin/oxidative stress biomarkers in a cohort of foundry workers.

Method: Plasma levels of 79 lipid mediators, including oxylipinand un- mono- and polyunsaturated fatty acids were quantifiein 40 foundry workers sampled twice, using solid-phase extraction and ultra high-pressure liquid chromatography coupled tunispray tandem mass spectrometry (SPE-UHPLC-USI-MS/MS). Lipid levels were correlated with personal exposure measurements to respirable dust and RCS. Analysis of urinary oxylipin and oxidative stress markers are ongoing and these results will also be presented at the conference.

Results: Adjusted for covariates, seven lipids were significantly correlated with RCS exposure. These lipids were mainly linoleic acid derived oxylipins with 9,10-DiHOME demonstrating the strongest correlation. For respirable dust, five lipids correlated significantly with exposure, mainly eicosanoids, eg 8,9-DiHETrE. In general, there were no, or very few significant correlations between the lipid mediators and other inflammatory markers, such as interleukin-8, C-reactive protein and Serum amyloid A.

Conclusions: The observed associations between linoleic acid-derived oxylipins and RCS exposure suggest that these lipid mediators may play a previously underrecognized role in silica-induced inflammation and disease.

The aim of the study was to determine nano/sub-micron particle and dust exposure levels throughout the whole workflow at a Swedish metal additive manufacturing (AM) facility, focusing on the laser powder bed fusion (L-PBF) method. By evaluating particle levels and composition across different AM processes using both stationary and personal sampling, the study sought to improve exposure assessment and inform protective measures in the metal AM workplaces. Measurements were conducted during five measurement weeks, as five working days Monday-Friday, between October 2020 and October 2023. Personal particle measurements in the breathing zone were performed on Mondays and Fridays for 1 to 3 workers per day. Stationary particle and dust sampling were performed continuously at three locations each week to capture task-specific and temporal variation in emissions. Nano/sub-micron particle concentrations ranged from 0 to 3.3 million particles/cm3, with the highest peaks recorded in the post-processing area. Elevated levels were also detected, near the depowdering machine, by the bandsaw, and in the lunchroom, while levels near the printers were low (<10,000 particles/cm3). Personal exposure peaks occurred during printer cleaning, feedstock powder filling, dust removal with compressed air, post-processing, and packing. In contrast to the increased nano/sub-micron particle levels observed, respirable, and inhalable dust levels were very low. The study highlights the need to monitor particle exposure during both manufacturing and post-processing. Health risks associated with airborne particles are influenced by both exposure levels and the toxicological properties of materials. To ensure a safe and sustainable future for metal AM, comprehensive exposure assessment, risk evaluation, and the implementation of protective measures remain essential.

Nanoplastics have recently been detected in human liver tissue, raising concerns about their potential impact on liver function. However, early hepatocyte responses associated with nanoplastics exposure remain poorly understood. Here, we combined high-throughput Cell Painting-based phenomics, untargeted metabolomics, and Seahorse mitochondrial functional assay to investigate the effects of 100 nm polystyrene nanoplastics on human HepaRG hepatocytes, a surrogate for primary human hepatocytes. At the tested concentrations (6.25-100 µg/mL), exposure did not induce overt cytotoxicity, enabling assessment of early sublethal cellular responses. Phenomics revealed widespread subcellular perturbations, with 16.4% of the measured phenotypic features significantly altered. Mitochondria-associated features represented the dominant altered phenotypic signature, showing pronounced changes in granularity, texture, and radial distribution, alongside alterations in endoplasmic reticulum- and cytoskeleton-associated features. Untargeted metabolomics of intracellular metabolites and the extracellular secretome revealed metabolic alterations, characterized by changes consistent with altered β-oxidation, lipid handling, membrane stress, and central carbon metabolism, including changes in the tricarboxylic acid (TCA) cycle and amino acid catabolism. Pathway analysis identified the TCA cycle as one of the most significantly affected pathways (FDR = 0.028). Integrated phenomic-metabolomic analysis revealed strong correlations between mitochondrial phenotypic features and metabolites involved in lipid and energy metabolism, indicating a coordinated structural-metabolic response to polystyrene nanoplastics exposure. Functional assessment using Seahorse assay showed reduced basal and maximal respiration and decreased ATP-linked O2 consumption. Together, these findings provide evidence that 100 nm polystyrene nanoplastics elicit early mitochondria-associated phenotypic, metabolic, and functional responses prior to overt cytotoxicity under the tested conditions. They also highlight the value of phenomic-metabolomic-functional integration for profiling sublethal nanotoxicological responses and guiding future targeted mechanistic studies.

Formation of the NLRP3 inflammasome occurs in response to a wide range of triggers and leads to pyroptosis and release of IL-1 beta and IL-18. This has widely been considered an "all or nothing" response leading to similar cellular outcomes each time, once the inflammasome has formed, a view that has been challenged over the years. This assumption has largely been based on endpoint measurements at the population level, producing metrics that fail to adequately capture dynamic responses. Herein, we utilize live-cell imaging combined with an algorithmic approach to track individual ASC-GFP specks over time, formed in response to the triggers ATP, monosodium urate and nigericin. Using this approach, we report trigger-dependent differences in speck lifetime. The use of the proposed algorithm requires a relatively small dataset, while still providing insights into NLRP3 inflammasome dynamics downstream of inflammasome activation at the single-cell level.