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29 result(s) for "Marzi, Anne"
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Label-Free Digital Holographic Microscopy for In Vitro Cytotoxic Effect Quantification of Organic Nanoparticles
Cytotoxicity quantification of nanoparticles is commonly performed by biochemical assays to evaluate their biocompatibility and safety. We explored quantitative phase imaging (QPI) with digital holographic microscopy (DHM) as a time-resolved in vitro assay to quantify effects caused by three different types of organic nanoparticles in development for medical use. Label-free proliferation quantification of native cell populations facilitates cytotoxicity testing in biomedical nanotechnology. Therefore, DHM quantitative phase images from measurements on nanomaterial and control agent incubated cells were acquired over 24 h, from which the temporal course of the cellular dry mass was calculated within the observed field of view. The impact of LipImage™ 815 lipidots® nanoparticles, as well as empty and cabazitaxel-loaded poly(alkyl cyanoacrylate) nanoparticles on the dry mass development of four different cell lines (RAW 264.7, NIH-3T3, NRK-52E, and RLE-6TN), was observed vs. digitonin as cytotoxicity control and cells in culture medium. The acquired QPI data were compared to a colorimetric cell viability assay (WST-8) to explore the use of the DHM assay with standard biochemical analysis methods downstream. Our results show that QPI with DHM is highly suitable to identify harmful or low-toxic nanomaterials. The presented DHM assay can be implemented with commercial microscopes. The capability for imaging of native cells and the compatibility with common 96-well plates allows high-throughput systems and future embedding into existing experimental routines for in vitro cytotoxicity assessment.
Quantitative Phase Imaging as Sensitive Screening Method for Nanoparticle-Induced Cytotoxicity Assessment
The assessment of nanoparticle cytotoxicity is challenging due to the lack of customized and standardized guidelines for nanoparticle testing. Nanoparticles, with their unique properties, can interfere with biochemical test methods, so multiple tests are required to fully assess their cellular effects. For a more reliable and comprehensive assessment, it is therefore imperative to include methods in nanoparticle testing routines that are not affected by particles and allow for the efficient integration of additional molecular techniques into the workflow. Digital holographic microscopy (DHM), an interferometric variant of quantitative phase imaging (QPI), has been demonstrated as a promising method for the label-free assessment of the cytotoxic potential of nanoparticles. Due to minimal interactions with the sample, DHM allows for further downstream analyses. In this study, we investigated the capabilities of DHM in a multimodal approach to assess cytotoxicity by directly comparing DHM-detected effects on the same cell population with two downstream biochemical assays. Therefore, the dry mass increase in RAW 264.7 macrophages and NIH-3T3 fibroblast populations measured by quantitative DHM phase contrast after incubation with poly(alkyl cyanoacrylate) nanoparticles for 24 h was compared to the cytotoxic control digitonin, and cell culture medium control. Viability was then determined using a metabolic activity assay (WST-8). Moreover, to determine cell death, supernatants were analyzed for the release of the enzyme lactate dehydrogenase (LDH assay). In a comparative analysis, in which the average half-maximal effective concentration (EC50) of the nanocarriers on the cells was determined, DHM was more sensitive to the effect of the nanoparticles on the used cell lines compared to the biochemical assays.
Largazole targets Musashi protein expression via miR-125b-5p and sensitizes triple-negative breast cancer cells to radiation
Recent findings implicate the histone deacetylase (HDAC) inhibitor largazole as an inhibitor of Musashi RNA-binding protein function. Here, we assess this interplay and evaluate the relevance of largazole for triple-negative breast cancer (TNBC) progression and resistance to radiotherapy. Primary patient-derived TNBC cells and cell lines were treated with largazole and cell vitality, proliferation, motility, cell cycle, DNA synthesis as well as repair, and stemness were analyzed via MTT assay, digital holographic microscopy, and flow cytometry. To unravel the connection between largazole treatment and Musashi expression, miR-125b-5p was assessed after largazole treatment, and overexpressed as well as downregulated in TNBC wildtype cells to determine influence on Musashi levels. Targeted mRNA and protein expression analyses were complemented with RNA sequencing data after largazole treatment. Finally, DNA double strand breaks and post-radiogenic survival were quantified using γ-H2AX, 53BP1, and clonogenic assays. Largazole showed reduced metabolic activity in TNBC, but not in non-malignant cultures. Largazole treatment strongly abrogated proliferation, DNA synthesis, cell motility, and induced a cell cycle arrest. Levels of the Musashi proteins were downregulated after largazole treatment via upregulation of the miR-125b-5p. Protein expression and RNA sequencing analysis indicated a loss of cancer stemness-, cell cycle progression-, and DNA repair-associated signaling. Consequently, radiotherapy-induced DNA double strand breaks were increased while post-radiogenic cell survival was decreased in largazole-treated samples. The HDAC inhibitor largazole compromises tumor growth and motility and downregulates the Musashi proteins via the miR-125b-5p in TNBC. Additionally, largazole acts as a radiosensitizer by attenuating DNA repair, therefore supporting therapeutic efficacy.
Interlaboratory evaluation of a digital holographic microscopy–based assay for label-free in vitro cytotoxicity testing of polymeric nanocarriers
State-of-the-art in vitro test systems for nanomaterial toxicity assessment are based on dyes and several staining steps which can be affected by nanomaterial interference. Digital holographic microscopy (DHM), an interferometry-based variant of quantitative phase imaging (QPI), facilitates reliable proliferation quantification of native cell populations and the extraction of morphological features in a fast and label- and interference-free manner by biophysical parameters. DHM therefore has been identified as versatile tool for cytotoxicity testing in biomedical nanotechnology. In a comparative study performed at two collaborating laboratories, we investigated the interlaboratory variability and performance of DHM in nanomaterial toxicity testing, utilizing complementary standard operating procedures (SOPs). Two identical custom-built off-axis DHM systems, developed for usage in biomedical laboratories, equipped with stage-top incubation chambers were applied at different locations in Europe. Temporal dry mass development, 12-h dry mass increments and morphology changes of A549 human lung epithelial cell populations upon incubation with two variants of poly(alkyl cyanoacrylate) (PACA) nanoparticles were observed in comparison to digitonin and cell culture medium controls. Digitonin as cytotoxicity control, as well as empty and cabazitaxel-loaded PACA nanocarriers, similarly impacted 12-h dry mass development and increments as well as morphology of A549 cells at both participating laboratories. The obtained DHM data reflected the cytotoxic potential of the tested nanomaterials and are in agreement with corresponding literature on biophysical and chemical assays. Our results confirm DHM as label-free cytotoxicity assay for polymeric nanocarriers as well as the repeatability and reproducibility of the technology. In summary, the evaluated DHM assay could be efficiently implemented at different locations and facilitates interlaboratory in vitro toxicity testing of nanoparticles with prospects for application in regulatory science.Graphical abstract
Standardization of an in vitro assay matrix to assess cytotoxicity of organic nanocarriers: a pilot interlaboratory comparison
Nanotechnologies such as nanoparticles are established components of new medical devices and pharmaceuticals. The use and distribution of these materials increases the requirement for standardized evaluation of possible adverse effects, starting with a general cytotoxicity screening. The Horizon 2020 project “Regulatory Science Framework for Nano(bio)material-based Medical Products and Devices (REFINE)” identified in vitro cytotoxicity quantification as a central task and first step for risk assessment and development for medical nanocarriers. We have performed an interlaboratory comparison on a cell-assay matrix including a kinetic lactate dehydrogenase (LDH) release cell death and WST-8 cell viability assay adapted for testing organic nanocarriers in four well-characterized cell lines of different organ origins. Identical experiments were performed by three laboratories, namely the Biomedical Technology Center (BMTZ) of the University of Münster, SINTEF Materials and Chemistry (SINTEF), and the National Institute for Public Health and the Environment (RIVM) of the Netherlands according to new standard operating procedures (SOPs). The experiments confirmed that LipImage™ 815 lipidots® are non-cytotoxic up to a concentration of 128 µg/mL and poly(alkyl cyanoacrylate) (PACA) nanoparticles for drug delivery of cytostatic agents caused dose-dependent cytotoxic effects on the cell lines starting from 8 µg/mL. PACA nanoparticles loaded with the active pharmaceutical ingredient (API) cabazitaxel showed a less pronounced dose-dependent effect with the lowest concentration of 2 µg/mL causing cytotoxic effects. The mean within laboratory standard deviation was 4.9% for the WST-8 cell viability assay and 4.0% for the LDH release cell death assay, while the between laboratory standard deviation was 7.3% and 7.8% for the two assays, respectively. Here, we demonstrated the suitability and reproducibility of a cytotoxicity matrix consisting of two endpoints performed with four cell lines across three partner laboratories. The experimental procedures described here can facilitate a robust cytotoxicity screening for the development of organic nanomaterials used in medicine.Graphical abstract
Children’s Independent Mobility: Current Knowledge, Future Directions, and Public Health Implications
Environmental changes significantly impact health behavior. Active travel behavior is mostly affected by increasing motorization, urban sprawl, and traffic safety. Especially for children, active and independent travel can contribute to physical activity, social and motor development, and other health-related outcomes. A reduced number of children engaging in independent mobility over the last 20 years demanded researchers to further examine the construct of children’s independent mobility. By examining relevant literature, this narrative review aims to provide the current state of knowledge on children’s independent mobility, and identify future directions in research, as well as practical implications. From a public health perspective, considering children’s independent mobility in intervention programs is recommended, since it is associated with numerous health and environmental benefits. To develop interventions, multilevel socio-ecological influences on children’s independent mobility are widely examined; however, evidence is limited due to heterogeneous measurements and a lack of high-quality prospective studies. To oppose the decline in children’s independent mobility, further analysis using comparable measures is needed to understand the determinants of children’s independent mobility and to enable international comparison.
Social and physical environmental correlates of independent mobility in children
Background: Children's independent mobility (CIM) is an important contributor to physical activity and health in children. However, in the last 20 years CIM has significantly decreased. To develop effective intervention programs to promote CIM, the impact of the environment on CIM must be identified. This review seeks to provide an overview of sex/gender-specific socio-ecological correlates of CIM. Methods: A systematic literature search of five databases (PubMed, PsycInfo, Scopus, Medline, Web of Science) was conducted with a priori defined eligibility criteria and identified 1838 potential articles published between January 1990 and November 2017. Two independent reviewers screened the literature and identified and rated methodologi- cal quality of the studies. Related factors of CIM were summarized separately for CIM license (parental permission to travel independently) and CIM destination (destinations to which a child travels independently), and separately for boys and girls using a semi-quantitative method. Results: Twenty-seven peer-reviewed journal articles were identified which examined the relationship between the social and physical environment and CIM. Only seven studies reported results divided by sex/gender. Most associa- tions between the environment and CIM were found in the expected direction (positive or negative) or not associ- ated at all. The social environment seemed to be more influential for ensuring CIM than the physical environment. Neighborhood safety, fear of crime and stranger, parental support, and perception of traffic were important social environmental factors influencing CIM, while car ownership, distance, and neighborhood design were relevant physi- cal environmental attributes. Few studies examined sex/gender-related environmental correlates of independent mobility, and those findings were inconsistent. Conclusion: The findings of this systematic review serve as suggestions for intervention programs to increase CIM and to identify future directions in research. To establish a robust comprehension of the impact of the social and physical environment on CIM, further sex/gender-sensitive studies using comparable measurements for CIM and environmental correlates are needed. (Autor).
Parental and peer support and modelling in relation to domain-specific physical activity participation in boys and girls from Germany
Physical activity (PA) as a precondition of child development is related with social environmental correlates. However, domain-specific PA and gender issues have been neglected in studies on social support and modelling and PA in school-aged children. The aim of this study was to assess the relationships of parental and peer modelling and social support with domain-specific PA participation in a large sample of school-aged children, taking gender into account. 3,505 school children aged 6 to 17 years old participated in the German nationwide 'MoMo' cohort-study. By using the MoMo-PAQ the participants and their parents provided self-report data on perceived social support and social modelling and domain-specific PA participation. Relationships of social environmental variables and the physical outcomes were analysed by logistic regression analyses. At secondary school level, girls were less likely than boys to participate in physical activity in and outside of sports clubs, extra-curricular physical activity and in outdoor play (p < 0.05), but at primary school level this pattern only applied to club sport (p < 0.01). Girls also received less social support than boys (p < 0.01). Physical activity participation in all domains was associated with any of the social support and modelling variables and differences between physical activity domains and between boys and girls occurred. Most consistently physical activity in sports clubs was related with the social environmental correlates in boys (primary school: R2 = 0.60; secondary school: R2 = 0.45) and girls (primary school: R2 = 0.53; secondary school: R2 = 0.47). In future, reciprocal relationships of social environmental variables and PA should be considered in longitudinal studies to obtain insights into the direction of the associations. Furthermore, interventions encompassing the social environment and focussed particularly on the promotion of domain-specific PA in girls in secondary school-age are warranted.
Translating genomic tools to Raman spectroscopy analysis enables high-dimensional tissue characterization on molecular resolution
Spatial transcriptomics of histological sections have revolutionized research in life sciences and enabled unprecedented insights into genetic processes involved in tissue reorganization. However, in contrast to genomic analysis, the actual biomolecular composition of the sample has fallen behind, leaving a gap of potentially highly valuable information. Raman microspectroscopy provides untargeted spatiomolecular information at high resolution, capable of filling this gap. In this study we demonstrate spatially resolved Raman “spectromics” to reveal homogeneity, heterogeneity and dynamics of cell matrix on molecular levels by repurposing state-of-the-art bioinformatic analysis tools commonly used for transcriptomic analyses. By exploring sections of murine myocardial infarction and cardiac hypertrophy, we identify myocardial subclusters when spatially approaching the pathology, and define the surrounding metabolic and cellular (immune-) landscape. Our innovative, label-free, non-invasive “spectromics” approach could therefore open perspectives for a profound characterization of histological samples, while additionally allowing the combination with consecutive downstream analyses of the very same specimen. Spatial transcriptomics of histological sections have revolutionized basic research, while the actual biomolecular composition of the sample has fallen behind. Here, the authors propose a novel approach to analyze untargeted spatiomolecular Raman spectroscopy data through bioinformatic tools developed for transcriptomic analyses, and integrate them with additional Omics techniques.
The EAT–Lancet Commission on healthy, sustainable, and just food systems
The global context has shifted dramatically since publication of the first EAT–Lancet Commission in 2019, with increased geopolitical instability, soaring food prices, and the COVID-19 pandemic exacerbating existing vulnerabilities and creating new challenges. However, food systems remain squarely centred at the nexus of food security, human health, environmental sustainability, social justice, and the resilience of nations. Actions on food systems strongly impact the lives and wellbeing of all and are necessary to progress towards goals highlighted in the Sustainable Development Goals, the Paris Agreement, and the Kunming–Montreal Global Biodiversity Framework. Although current food systems have largely kept pace with population growth, ensuring sufficient caloric intake for many, they are the single most influential driver of planetary boundary transgression. More than half of the world's population struggles to access healthy diets, leading to devastating consequences for public health, social equity, and the environment. Although hunger has declined in some regions, recent increases linked to expanding conflicts and emergent climate change impacts have reversed this positive trend. Obesity rates continue to rise globally, and the pressure exerted by food systems on planetary boundaries shows no signs of abating. In this moment of increasing instability, food systems still offer an unprecedented opportunity to build the resilience of environmental, health, economic, and social systems, and are uniquely placed to enhance human wellbeing while also contributing to Earth-system stability. This updated analysis builds upon the 2019 EAT–Lancet Commission, expanding its scope and strengthening its evidence base. The first Commission defined food group ranges for a healthy diet and identified the food systems' share of planetary boundaries. In this Commission, we add an analysis of the social foundations for a just food system, and incorporate new data and perspectives on distributive, representational, and recognitional justice, providing a global overview on equity in food systems. Substantial improvements in modelling capacity and data analysis allow for the use of a multimodel ensemble to project potential outcomes of a transition to healthy and sustainable food systems. The planetary health diet (PHD) remains a cornerstone of our recommendations and can be seen as a framework within which diverse and culturally appropriate diets can exist. Robust updated evidence reinforces a strong association with improved health outcomes, large reductions in all-cause mortality, and a substantial decline in the incidence of major diet-related chronic diseases. The reference PHD emphasises a balanced dietary pattern that is predominantly plant-based, with moderate inclusion of animal-sourced foods and minimal consumption of added sugars, saturated fats, and salt. Successful implementation of the PHD requires careful consideration of cultural contexts and the promotion of culturally appropriate and sustainable dietary traditions. This diversity of contexts, bounded by the PHD's reference values, represents substantial flexibility and choice across cultures, geographies, and individual preferences. However, when confronted by climate, biodiversity, health, and justice crises, transformation will require urgent and meaningful changes in our individual and collective behaviours and our culture of unhealthy, unjust, and unsustainable food production and consumption. For the first time, we quantify the global food systems' share of all nine planetary boundaries. These food system boundaries confirm that food is the single largest cause of planetary boundary transgressions, driving the transgression of five of the six breached boundaries. In addition, food systems exert a notable impact on the transgressed climate boundary and on the ocean acidification boundary. Unsustainable land conversion, particularly deforestation, remains a major driver of biodiversity loss and climate change, highlighting the need for zero conversion of all remaining intact ecosystems. Food systems account for the near totality of nitrogen and phosphorus boundary transgression, emphasising the improvements needed in nutrient management, efficient nutrient redistribution, and circular nutrient systems. The massive use of novel entities in food production, processing, and packaging (ranging from plastics to pesticides) remains a major concern but is alarmingly understudied. Our assessment of justice integrates three dimensions—distributive, representational, and recognitional—within a human rights framing that includes the rights to food, a healthy environment, and decent work. Analyses reveal important inequities in access to healthy diets, decent work conditions, and healthy environments, disproportionately affecting marginalised groups in low-income regions. We therefore propose nine social foundations that enable these rights to be met, and are able to assess the global status of six. Enabling access to, affordability of, and demand for healthy diets is paramount. Equally crucial is the right to live and work within a non-toxic environment and a stable climate system, as we recognise the profound impact of environmental degradation on human health and wellbeing. Furthermore, a living wage and meaningful representation would allow individuals to actively participate in building healthy, sustainable, and just food systems. However, nearly half of the world's population falls below these social foundations, undermining their ability to meet basic human rights. At the same time, the dietary patterns of most (6·9 billion people) of the world exert pressures that threaten further planetary boundary transgression. The destabilising effect of unhealthy overconsumption on the Earth's systems highlights the importance of viewing healthy diets not just as a human right, but also as a shared responsibility.