Iron is the crucial element for living organisms and its deficiency is described as the most common nutritional disorder all over the world. Nowadays, more effective and safe iron supplementation strategies for both humans and animals become one of the most important challenges in the therapy of nutritional deficiencies. Our previous in vivo studies confirmed safety and biodegradability of in-house manufactured zinc oxide-based nanoparticles and their rapid distribution to majority of organs and tissues in the body. In vitro examinations performed on Caco-2 cell line, a model of epithelial cells of the gastrointestinal tract, revealed a low toxicity of studied nanomaterials. In the current study, we investigated biodegradable zinc oxide nanoparticles doped with Fe(III) as a perspective supplementation strategy for iron deficiency. Biodegradable ZnO:Fe nanoparticles were intra-gastrically administered to adult mice and following 24 h, animals were sacrificed with collection of internal organs for further analyses. The iron concentration measured with atomic absorption spectrometry and histological staining (Perl’s method) showed a rapid distribution of iron-doped nanoparticles to tissues specifically related with iron homeostasis. Accumulation of iron was also visible within hepatocytes and around blood vessels within the spleen, which might indicate the transfer of Fe-doped nanoparticles from the bloodstream into the tissue. Reassuming, preliminary results obtained in the current study suggest that biodegradable ZnO nanoparticles doped with Fe might be a good carriers of exogenous iron in the living body. Therefore, subsequent investigations focus on determination an exact mechanisms related with an iron deposition in the tissue and influence of nanoparticle carriers on iron metabolism are required.

Nanomaterials, including engineered particles with dimensions in the nanoscale range (≤100 nm), are increasingly used in the food and feed sectors, particularly in applications such as nanoencapsulation of bioactive compounds, targeted nutrient delivery, texture improvement, and shelf-life extension. This study analyses the European Union's legal framework, including the 2011 and 2022 European Commission recommendations, Regulation (EC) No 178/2002, Regulation (EU) 2015/2283, and European Food Safety Authority (EFSA) guidance documents, and highlights definitional ambiguities and regulatory inconsistencies that hinder effective risk assessment and management. Ongoing debates concerning the 50% particle size threshold used to define a nanomaterial illustrate these challenges. Using a qualitative and comparative legal approach grounded in the precautionary principle and scientific uncertainty, the study identifies major gaps in current risk assessment, including issues related to particle accumulation, long-term exposure, and the lack of validated methods for characterisation and detection. Based on these findings, key regulatory improvements are proposed: clearer and harmonised definitions, updated classification thresholds, stronger requirements for data on physicochemical properties, and enhanced transparency in risk communication. These recommendations aim to inform the ongoing revision of EFSA guidance (2024–2029) and support the development of a coherent and effective regulatory framework for nanomaterials in food and feed.

With the spread of nanotechnology use in industry, exposure to nanomaterials is currently exponentially increasing. With reports indicating nanoparticles’ ability to pass through key biological barriers—gastrointestinal, lung, skin, blood-brain and the placenta barriers—the question of their safety, particularly the risks associated with embryonic development, arises. The aim of this article is to verify the impact of ZnO nanoparticles, which are commonly used and considered to be safe for adult organisms on the developing embryo. In the current study, the influence of the dose and shape of ZnO nanoparticles (oval vs. long) was evaluated in the chicken embryo model. The oxidative stress (superoxide dismutase (SOD)) activity, malondialdehyde (MDA) and carbonylated protein ((CP) levels), and gene expression changes (full genomic microarray study) were tested. We found that at both doses (10 µg/mL and 100 µg/mL, 100 µL into the air chamber) neither elongated nor oval ZnO nanoparticles changed in ovo mortality. Long ZnO nanoparticles had a lesser and more delayed impact on evaluated parameters, regardless of their higher in vitro toxicity. However, both nanoparticle forms induced changes in the oxidoreductive potential and affected expression of a significant number (1487 for oval and 548 for long ZnO nanoparticles) of identified genes during early embryo development.

Nanotechnology as a new field of science is broadly exploited in a plethora of commercial uses. Biocompatible nanomaterials are also attractive for medical applications. However, an exact processes related with their biodistribution within the body needs to be examined. This study deals with future perspectives for biodegradable nanoparticle on the example of fluorescent ZnO NPs (zinc oxide nanoparticles), doped with europium (Eu) ions. The aim of the study was to evaluate distribution processes of biodegradable ZnO:Eu NPs within the living organism. ZnO:Eu NPs were administered intra-gastric (IG) (10 mg/ml, 0.3 ml/mouse) to adult Balb-c mice (n=35) and following 3h, 24h, 7d, 14d and 1m mice were sacrificed and internal organs were collected, as was described before [1]. For determination the excretion patterns of these nanostructure, ZnO NPs were orally administered to mice (n=24) with further measurement of zinc content in the feces of tested animals. All procedures were conducted according to local and EU regulations and approved by the LEC 44/2012. No pathological/behavioral changes were observed in mice. Biodegradable ZnO:Eu NPs revealed ability to overcome majority of physiological barriers in the organism, which renders them invaluable tool for biomedical applications. After 3h the presence of fluorescent NPs was already observed in key tissues and the peak of NPs distribution was observed at 24 h after IG in majority of tissues, including brain. Moreover, obtained results revealed fast and efficient clearance of ZnO NPs from the living organism, even following multiple administration of nanostructures (up to 4d after IG).

With the growing use of nanotechnology, the issue of exposure to non-biodegradable nanomaterials is becoming increasingly significant, raising concerns about their potential impact on developing organisms. Their use in dentistry, optoelectronics and biomedicine leads to environmental exposure. Zirconium oxide (ZrO₂) and yttrium oxide (Y₂O₃) nanoparticles are chemically stable and poorly soluble materials; however, their embryotoxicity remains extremely poorly characterised. This study assessed the effect of ZrO₂ and Y₂O₃ nanoparticles on the development of chicken embryos. The nanoparticles were administered into the air chamber of the egg on the first day of incubation at concentrations of 10 and 100 µg/mL. The redox status was assessed based on superoxide dismutase activity, malondialdehyde content and the level of carbonylated proteins. Transcriptomic responses were evaluated using a whole-genome microarray, and selected genes were verified by qPCR. Both types of nanoparticles induced time-dependent changes in markers of oxidative stress. Transcriptomic analysis revealed distinctly different responses, with seven genes showing altered expression following ZrO₂ administration, compared with 555 following Y₂O₃ administration. These results indicate that non-biodegradable metal oxide nanoparticles can influence the redox balance and gene expression during early embryonic development, with the extent of the response depending on the type of nanoparticle.

Carnivorous plants, such as Nepenthes (Nepenthaceae), possess a unique feature: the external digestion of animal-origin food. Nepenthes × ventrata pitchers are filled with digestive fluid containing: enzymes, small regulatory compounds and reactive oxygen species (ROS), which also act as signalling molecules. The aim of this study was to investigate the pattern of ROS content and to characterise enzymatic and non-enzymatic ROS modulators in the digestive fluid of N. × ventrata at various developmental stages of the pitcher. Significant changes were observed in the levels of hydrogen peroxide (H₂O₂) and hydroxyl radical (^•OH) throughout trap development. The highest concentration of H₂O₂ was found in aged pitchers, while the highest level of ^•OH was recorded in freshly opened immature traps. These findings corresponded with superoxide dismutase and class III peroxidase activities. After maturation of the trap, there was an increase in the activity of diamine and polyamine oxidases. We suggest that the production of ROS in the digestive fluid of pitcher plants at different stages of trap development is controlled by the redox modulatory system. These findings provide a basis for further research into how the regulation of ROS content supports trap development and digestive functions.