In the biomedical field, gold nanoparticles (GNPs) have attracted the attention of the scientific community thanks to their high potential in both diagnostic and therapeutic applications. The extensive use of GNPs led researchers to investigate their toxicity, identifying stability, size, shape, and surface charge as key properties determining their impact on biological systems, with possible strategies defined to reduce it according to a Safe-by-Design (SbD) approach. The purpose of the present work was to analyze the toxicity of GNPs of various sizes and with different coating polymers on the developing vertebrate model, zebrafish. In particular, increasing concentrations (from 0.001 to 1 nM) of 6 or 15 nm poly-(isobutylene-alt-maleic anhydride)-graft-dodecyl polymer (PMA)- or polyethylene glycol (PEG)-coated GNPs were tested on zebrafish embryos using the fish embryo test (FET). While GNP@PMA did not exert significant toxicity on zebrafish embryos, GNP@PEG induced a significant inhibition of embryo viability, a delay of hatching (with the smaller size NPs), and a higher incidence of malformations, in terms of tail morphology and eye development. Transmission electron microscope analysis evidenced that the more negatively charged GNP@PMA was sequestered by the positive charges of chorion proteins, with a consequent reduction in the amount of NPs able to reach the developing embryo and exert toxicological activity. The mild toxic response observed on embryos directly exposed to GNP@PMA suggest that these NPs are promising in terms of SbD development of gold-based biomedical nanodevices. On the other hand, the almost neutral GNP@PEG, which did not interact with the chorion surface and was free to cross chorion pores, significantly impacted the developing zebrafish. The present study raises concerns about the safety of PEGylated gold nanoparticles and contributes to the debated issue of the free use of this nanotool in medicine and nano-biotechnologies.

Nanomaterials (NMs), including nanoparticles (NPs), offer promising potential in achieving the European Commission’s Green Deal goals of climate-neut

SMYD3 (SET and MYND domain containing protein 3) is a methylase over-expressed in cancer cells and involved in oncogenesis. While several studies uncovered key functions for SMYD3 in cancer models, the SMYD3 role in physiological conditions has not been fully elucidated yet. Here, we dissect the role of SMYD3 at early stages of development, employing mouse embryonic stem cells (ESCs) and zebrafish as model systems. We report that SMYD3 depletion promotes the induction of the mesodermal pattern during in vitro differentiation of ESCs and is linked to an upregulation of cardiovascular lineage markers at later stages. In vivo, smyd3 knockdown in zebrafish favors the upregulation of mesendodermal markers during zebrafish gastrulation. Overall, our study reveals that SMYD3 modulates levels of mesendodermal markers, both in development and in embryonic stem cell differentiation.

Combustion-derived particles (CDPs), due to the presence in their composition of several toxic and carcinogenic chemical compounds, such as polycyclic aromatic hydrocarbons (PAHs) and metals, are linked to several respiratory diseases, including lung cancer. Epithelial-to-mesenchymal transition (EMT) is a crucial step in lung cancer progression, involving several morphological and phenotypical changes. The study aims to investigate how exposure to CDPs from different biomass sources might be involved in cancer development, focusing mainly on the effects linked to EMT and invasion on human A549 lung cells. Biomass combustion-derived particles (BCDPs) were collected from a stove fuelled with pellet, charcoal or wood, respectively. A time course and dose response evaluation on cell viability and pro-inflammatory response was performed to select the optimal conditions for EMT-related studies. A significant release of IL-8 was found after 72 h of exposure to 2.5 μg/cm² BCDPs. The EMT activation was then examined by evaluating the expression of some typical markers, such as E-cadherin and N-cadherin, and the possible enhanced migration and invasiveness. Sub-acute exposure revealed that BCDPs differentially modulated cell viability, migration and invasion, as well as the expression of proteins linked to EMT. Results showed a reduction in the epithelial marker E-cadherin and a parallel increase in the mesenchymal markers N-cadherin, mainly after exposure to charcoal and wood. Migration and invasion were also increased. In conclusion, our results suggest that BCDPs with a higher content of organic compounds (e.g. PAHs) in their chemical composition might play a crucial role in inducing pro-carcinogenic effects on epithelial cells.

Rigid polyurethane, PUR, foams are a class of polymeric materials with remarkable insulation properties. Their functional properties throughout their lifespan are strongly affected by environmental parameters. Moreover, the ecotoxicity of PUR foams have not been completely explored, especially simulating real case scenarios, i.e., during the time of use or at the end of life (EoL). In this work, bio-based pristine and nanocomposite PUR foams, undergo a specific aging process (T=70°C, RH=90 %) at defined times (0, 2, and 14 days). The effects of aging time on foam properties and on their potential ecotoxicity are investigated. An ecotoxicity protocol is established to assess the leaching of foams in water, evaluating the reduction in metabolic activity in Aliivibrio fischeri and embryotoxicity in Danio rerio (zebrafish). Two case studies are considered: monolithic PUR foam panels (use phases) and granular PUR waste materials (EoL phase). Results demonstrate a non-relevant effect of the selected aging conditions on foam performance. No toxic effects are noticed upon aging for both foam monolithic materials. For EoL systems, the ecotoxicity depends on both the formulation and aging time. No aged pristine PUR foams induce high mortality rate, while nanocomposite foams have impact on both embryos mortality and malformation rate. For both cases, these effects are not observed for aged materials. This study provides valuable insights into how aging influences performance and toxicity across various life stages of innovative bio-based materials for construction sector.

Background: Veterinary autogenous vaccines (AVs) are emergency tools produced in a short timeframe from bacterial/viral/fungal isolates when commercial vaccines are not available and undergo strict quality assurance and safety tests before release. In accordance with the European Directive 2010/63/EU and the 3R principles, we evaluated for the first time the possible substitution of the final toxicity in vivo test (abnormal toxicity test) with an alternative cell-based and embryo-based assay. Methods: The five most requested different autogenous matrices (adopted to produce a customizable number of lots requested from customers) were tested in vitro in parallel for residual toxicity by in vitro fish embryo acute toxicity (FET) test and cytotoxicity assay (MTS) using serial dilutions, together with the authorized in vivo test. Results: Statistical analysis revealed different outcomes between the two in vitro methods, highlighting the greater discriminatory power of the MTS assay compared to the other, with results more like the observed in vivo ATT outcome (pass/negative). Conclusions: In this preliminary first dataset, FET appeared poorly compatible with several complex autogenous vaccine matrices, while the L929 MTS assay yielded interpretable viability thresholds for all tested matrices. These findings support further qualification of MTS as part of an integrated non-animal batch characterization strategy, but they do not yet establish replacement of the in vivo test for veterinary autogenous vaccine quality control.