This NanoTrust Dossier provides an overview of occupational exposure limits for ENMs in Europe. It highlights the challenges in establishing these limits and effectively safeguarding workers in a rapidly evolving field, and presents initiatives to accelerate the toxicity assessment of nanomaterials.

Nano- and microplastics (NMPs) are ubiquitous, persistent, and, as is now widely recognised, a global problem for humans and the environment. Because of the many different types of plastic from which NMPs are derived, conducting a general risk assessment is challenging. In addition, many plastics contain additives such as UV stabilisers or plasticisers that have hormonal effects – so-called endocrine disruptors (EDs) – and can easily be released from the plastics. Furthermore, some endocrine disruptors can strongly adhere to the surface of NMP particles and spread with them throughout the environment.
The effects of endocrine disruptors on humans and the environment remain partially unclear, as they can be very diverse and species-specific, making monitoring difficult. However, a causal link between exposure to endocrine disruptors and various human diseases has now been established. Adverse effects have also been observed in other organisms following exposure to endocrine disruptors, particularly in relation to reproduction.
Even if greener alternatives (e.g. bioplastics) could replace conventional plastics in the future, a significant influx of NMPs into the environment and the use of hormonally active substances can still be expected in the coming decades. Therefore, it is of utmost importance to establish additional test systems to protect human health and the environment, especially at the level of organisms that may facilitate the trophic transfer of EDs into the food chain.
This dossier explores general issues related to NMPs, EDs, and ecotoxicological risk assessment using the aquatic snail Biomphalaria glabrata.

Concluding this three-part series on Engineered Living Materials (ELMs), this dossier builds upon the previously discussed Biogenic Composition Ratio and production methodologies by analysing ELMs through the lens
of material features and hierarchical organisation across length scales. We explore how nano-, micro-, and macrostructural properties emerge from biological components, enabling functionalities such as self-healing and adaptivity. The dossier closes by identifying key challenges – such as vascularisation, scalability, and biosafety – that must be overcome to advance ELMs into practical applications.
This synthesis aims to inspire future research by providing a multidimensional perspective on the design and implementation of ELMs.

Building on the foundations, classifications and future potentials established in the NanoTrust-Dossier 64 ”Engineered Living Materials I”, this dossier explores the ELMs landscape in more detail, introducing the Biogenic Composition Ratio (BCR) as a categorisation scheme and providing an in-depth review of ELMs types ranging from fully biogenic to bioinspired materials. Additionally, production methodologies such as lamination, bioprinting, and electrospinning are discussed in ELMs fabrication. This dossier serves as a transition towards examining ELMs properties across length scales. It addresses the complex challenges inherent in designing and scaling ELMs, which are elaborated upon in the concluding part.

Engineered Living Materials (ELMs) incorporate living organisms in the synthesis process or seamlessly integrate them into conventional technological substrates, giving rise to novel functional materials. The transformative impact of ELMs spans various length scales and domains, such as construction, biomedicine and wearable technology. This impact arises from their exceptional attributes, including self-repair mechanisms, environmental responsiveness and inherent biocompatibility. This NanoTrust Dossier thoroughly examines the current state of ELMs production, offering a comprehensive systematic classification based on various parameters and elucidates recent strides in this dynamic field. Exploring ELMs unveils their scientific intricacies and underscores their potential to revolutionize and redefine material technologies in various applications.

Innovative chemicals and materials, such as advanced materials, are increasingly used in various applications. Advanced materials, like nanomaterials or biopolymers pose new challenges for established safety and risk assessments because of their unique properties, such as their size, shape, and surface characteristics, that distinguish them from conventional materials. In recent years, concepts such as “Safe by Design” (SbD) have been developed for nanomaterials to integrate safety aspects into the early stages of design and development. This concept has been further developed, extended to other advanced materials and chemicals in general, and expanded to include the aspect of sustainability in form of “Safe and Sustainable by Design” (SSbD). In 2022, the European Commission’s Joint Research Centre (JRC) presented a framework for safety and sustainability assessment aimed at helping to achieve the ambitious goals of the European Green Deal and the Chemical Strategy for Sustainability (CSS). The SSbD framework is intended to help companies and organisations assess not only safety but also environmental and socioeconomic sustainability, ensuring these factors are considered when (re)designing chemicals and materials. Application of the SSbD concept is currently voluntary. Because of the concept’s complexity and frequent lack of data, practical implementation remains a significant challenge for manufacturers. To effectively promote adoption of the SSbD concept, particularly amongst small and medium-sized enterprises (SMEs), appropriate framework conditions and additional measures to develop competence, cooperation, coordination, and support are needed.

Zunehmend werden innovative Chemikalien und Materialien, wie Advanced Materials, in den verschiedensten Anwendungsbereichen eingesetzt. Advanced Materials, zu denen zum Beispiel Nanomaterialien oder Biopolymere zählen, stellen die etablierte Sicherheitsund Risikobewertung vor neue Herausforderungen, da sie aufgrund ihrer Größe, Form und Oberflächenbeschaffenheit besondere Eigenschaften aufweisen, die sie von konventionellen Materialien unterscheiden. In den letzten Jahren wurden Konzepte wie z. B. „Safe-byDesign“ für Nanomaterialien entwickelt, um den Sicherheitsaspekt bereits in der frühen Design- bzw. Entwicklungsphase zu integrieren. Dieses Konzept wurde weiterentwickelt, auf andere Advanced Materials und generell auf Chemikalien ausgeweitet sowie um den Aspekt der Nachhaltigkeit zu „Safe-and-Sustainable-by-Design“ (SSbD) erweitert. Ein Rahmenwerk für eine Sicherheits- und Nachhaltigkeitsbewertung wurde im Jahr 2022 vom Joint Research Centre (JRC) der Europäischen Kommission vorgelegt und soll dazu beitragen, die ambitionierten Ziele des europäischen „Green Deal“ und die der „Chemical Strategy for Sustainability“ (CSS) zu erreichen. Das SSbD-Rahmenwerk soll Unternehmen und Organisationen Hilfestellung bieten, nicht nur die Sicherheit, sondern auch die ökologische und sozioökonomische Nachhaltigkeit zu bewerten und diese beim (Re-)Design von Chemikalien und Materialien zu berücksichtigen. Eine Anwendung des SSbD-Konzepts beruht derzeit auf Freiwilligkeit. Die praktische Umsetzung stellt für Hersteller aufgrund der Komplexität und oftmals fehlender Daten eine umfangreiche Aufgabe dar. Geeignete Rahmenbedingungen und zusätzliche Maßnahmen zum Kompetenzaufbau, zur Kooperation und Koordination sowie zur Unterstützung sind notwendig, um eine Umsetzung des SSbDKonzeptes in Unternehmen – insbesondere in kleinen und mittleren Unternehmen (KMUs) – weiterhin zu fördern.

In der Zahnheilkunde zeigt sich in den letzten Jahren ein Trend zur Verwendung von metallfreien Zahnimplantaten. Implantate aus Titan, deren Einsatz als Zahnersatz jahrzehntelang als „Goldstandard“ galt, können mittlerweile durch biokompatible Implantate, bestehend aus Keramikmaterialien ergänzt oder sogar ersetzt werden. Neben dem ästhetischen Aspekt eines keramischen Zahnersatzes, zeigt sich auch eine bessere Gewebeverträglichkeit bei Patient:innen, die allergisch gegen einzelne Bestandteile der Titanimplantate reagieren oder Vorerkrankungen wie Diabetes haben. Keramische Zahnimplantate bestehen unter anderem aus Zirkoniumdioxid (ZrO2) mit hoher Beständigkeit und Lebensdauer. Diese zeigen auch verbesserte Einheilungschancen in den Knochen (Osseointegration). Insgesamt ergeben sich dadurch neue Chancen in der Zahnheilkunde. Keramik ist ein inertes (nicht reaktives) Material und wird in der Orthopädie, z. B. für Hüftimplantate bereits länger als biokompatibler Werkstoff verwendet. Allerdings könnten beim Setzen oder Tragen der Zahnimplantate entweder technische Nanomaterialien, die in den Keramikkompositen eingesetzt werden, freigesetzt werden, und/oder es kann nanoskaliger Abrieb in Form von „sekundären“ Nanopartikeln entstehen. Dieser Abrieb kann in weiterer Folge entweder verschluckt oder eingeatmet werden. Bei Zulassungsverfahren für innovative Kompositwerkstoffe ist es daher unerlässlich, mögliche Gesundheitsrisiken zu berücksichtigen und nanospezifische Toxizitätseffekte näher zu untersuchen. Bislang sind keine negativen Wechselwirkungen im menschlichen Körper bekannt, jedoch gibt es bisher kaum Langzeitstudien zu möglichen Risiken für Mensch und Umwelt. Dieses Dossier erläutert die Materialeigenschaften von keramischen Zahnimplantaten im Vergleich zu herkömmlichen Implantaten aus Titan und bietet einen Überblick über mögliche Risiken und Chancen zur Verwendung dieses Werkstoffes in der Zahnimplantologie.

Nanocarriers are innovative delivery and encapsulation systems with different chemical compositions and structures and are classified as advanced materials. They are used in a variety of applications, especially in medicine, cosmetics, and agriculture, as well as in food supplements and household products. Nanocarriers can protect sensitive active ingredients, delay their release, and even enable targeted delivery to the site of action, thereby increasing effectiveness and reducing any side effects. In the scientific literature, the term “nanocarrier” covers not only nanomaterials up to a size of 100 nm according to the definition proposed by the European Commission, but also structures up to 1,000 nm. At present, there is no uniform definition or categorisation of nanocarriers. In this dossier, they are classified on the basis of their origin and chemical composition, and categorised as organic, inorganic, and hybrid systems (material combinations of organic and inorganic materials) as well as supraparticles. To date, there has been little research on how nanocarrier systems behave in the various environmental compartments (soil, water, air). Analytical challenges and the lack of standardised test protocols make comprehensive risk assessments difficult.