TY - CONF A1 - Thünemann, Andreas T1 - The Single Chain Architecture of (Bio)Polymers in Contact with Nanoplastics N2 - In contrast to microplastics, little is known about nanoplastics (1 to 100 nm). In order to make the dectecability of nanoplasics more reliable, we started to develop nanoplastic reference materials. This project also aims to anser the question of how the single chain conformation of bio(polymers) changes in contact with nanoplastics. Small-angle X-ray and neutron scattering methods are suitable methods for studing this topic. Recently the soft and hard interactions between polystyrene nanoplasics and human serum albumin corona was investigated with small-angle neutron scattering. Here we concentrate on small-angle X-ray scattering as our favorite method to study how (bio)polymers change their conformation in contact with nanoplastics. The scattering of bovine serum albumin in its native state can be detected easily. The scattering pattern of this biopolymer changes dramatically when its globular stucture changes to a coil structure. Modeling of chain conformations and the calculation of the scattering pattern is relatively easy to perform. Numerous model calculations will be provided to predict the changes of conformation of single bio(polymer) chains when in conatact with nanoplastics. These predictions will be compared with recent experimenal results from in situ measurments of bio(polymers) in contact with nanoplastics. The impact of temperature, polymer concentration and salt on the single-chain conformation changes will be discussed. T2 - PolyDays 2019 CY - Berlin, Germany DA - 11.09.2019 KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Protein KW - Nanoplastics PY - 2019 AN - OPUS4-48959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hildebrandt, Jana A1 - Thünemann, Andreas T1 - PP and PE nanoplastics in water N2 - Plastic debris in micron and nanometer scale pollutes the nature all over the world. The potential dangers of these pollutants remain unpredictable. While risk assessment studies on microplastics are already popular, nanoplastic has not yet reached the same focus of investigation. The reason for this difference is simple: There is a "methodological gap" in the analytics of plastic particles with a diameter smaller than 1 μm. Submicron and nanoplastic particles are currently not detectable in environmental matrices. Therefore, it is important for researchers to have a well-characterized nanoplastic material, that serves as a reference for nanoplastics found in nature. Our aim was to synthesize nanoplastics made from the most common used plastics such as polypropylene (PP) and polyethylene (PE). We found an easy way to form nanoparticles consisting of PP and PE (nano-PP/PE). Herein, nano-PP/PE was formed via a top-down method where the polymer was dispersed to acetone and then transferred to water. No surfactant is needed to obtain a dispersion which is stable for more than 35 weeks. The success of forming nanoplastics and their size was detected via scattering methods, predominantly dynamic light scattering. The chemical analysis of the nanoplastics was performed via Fourier Transform Infrared spectroscopy. Furthermore, electron microscopy was used to complement the results. To examine the good stability of the nanoparticles, zeta potential measurements were performed, which revealed zeta potentials of -30 to -40 mV. T2 - IUPAC-MACRO2020+ CY - Online meeting DA - 17.05.2021 KW - Nanoplastic PY - 2021 AN - OPUS4-53774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, M. B. A1 - Fahrenson, C. A1 - Givelet, L. A1 - Herrmann, T. A1 - Loescher, K. A1 - Böhmert, L. A1 - Thünemann, Andreas A1 - Braeuning, A. A1 - Sieg, H. T1 - Beyond microplastics ‑ investigation on health impacts of submicron and nanoplastic particles after oral uptake in vitro N2 - The continuously increasing use of plastics is supposed to result in a rising exposure of MNPs to humans. Available data on human health risks of microplastics after oral uptake increased immensely in the past years and indicates very likely only low risks after oral consumption. Concerning nanoplastics, uptake, transport and potential adverse effects after oral uptake are less well understood. This study aims to investigate differences between microplastic particles and particles in the submicron- and nanoscaled size derived from food-relevant polymers with a particle size range consistent with higher potential for cellular uptake, fate, and effects when applied to human intestinal and liver cells. This work includes the development of cellular and subcellular detection methods for synthetic polymeric particles in the micro- and nanometer-range, using Scanning Electron Microscopy, Small-Angle X-ray and Dynamic Light Scattering methods, Asymmetric Flow Field Flow Fractionation, octanol-water fractionation, fluorescence microscopy and flow cytometry. Polylactic acid (250 nm and 2 μm (polydisperse)), melamine formaldehyde (366 nm) and polymethylmethacrylate (25 nm) were thoroughly characterized. The submicro- and nanoplastic test particles showed an increased uptake and transport quantity through intestinal cells. Both types of particles resulted in observed differences of uptake behavior, most likely influenced by different lipophilicity, which varied between the polymeric test materials. Toxic effects were detected after 24 h only in overload situations for the particles in the submicrometer range. This study provides further evidence for gastrointestinal uptake of submicro- and nanoplastics and points towards differences regarding bioavailability between microplastics and smaller plastic particles that may result following the ingestion of contaminated food and beverages. Furthermore, the results reinforce the importance for studying nanoplastics of different materials of varying size, surface properties, polymer composition and hydrophobicity. KW - Small-angle X-ray scattering KW - SAXS KW - nanoparticle PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550741 DO - https://doi.org/10.1186/s43591-022-00036-0 VL - 2 SP - 1 EP - 19 PB - Springer Nature AN - OPUS4-55074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thünemann, Andreas A1 - Gruber, Alexandra A1 - Klinger, Daniel T1 - Amphiphilic Nanogels: Fuzzy Spheres with a Pseudo-Periodic Internal Structure N2 - Amphiphilic polymer nanogels (NGs) are promising drug delivery vehicles that extend the application of conventional hydrophilic NGs to hydrophobic cargoes. By randomly introducing hydrophobic groups into a hydrophilic polymer network, loading and release profiles as well as surface characteristics of these colloids can be tuned. However, very little is known about the underlying internal structure of such complex colloidal architectures. Of special interest is the question how the amphiphilic network composition influences the internal morphology and the “fuzzy” surface structure. To shine light into the influence of varying network amphiphilicity on these structural features, we investigated a small library of water-swollen amphiphilic NGs using small-angle X-ray scattering (SAXS). It was found that overall hydrophilic NGs, consisting of pure poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA), display a disordered internal structure as indicated by the absence of a SAXS peak. In contrast, a SAXS peak is present for amphiphilic NGs with various amounts of incorporated hydrophobic groups such as cholesteryl (CHOLA) or dodecyl (DODA). The internal composition of the NGs is considered structurally homologous to microgels. Application of the Teubner–Strey model reveals that hydrophilic PHPMA NGs have a disordered internal structure (positive amphiphilicity factor) while CHOLA and DODA samples have an ordered internal structure (negative amphiphilicity factor). From the SAXS data it can be derived that the internal structure of the amphiphilic NGs consists of regularly alternating hydrophilic and hydrophobic domains with repeat distances of 3.45–5.83 nm. KW - Polymer KW - Nanoparticle KW - SAXS PY - 2020 DO - https://doi.org/10.1021/acs.langmuir.0c01812 VL - 36 IS - 37 SP - 10979 EP - 10988 PB - American Chemical Society AN - OPUS4-51302 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wegner, Karl David A1 - Resch-Genger, Ute T1 - The 2023 Nobel Prize in Chemistry: Quantum dots N2 - The 2023 Nobel Prize in Chemistry was awarded to Aleksey I. Ekimov (prize share 1/3), Louis E. Brus (prize share 1/3), and Moungi G. Bawendi (prize share 1/3) for groundbreaking inventions in the field of nanotechnology, i.e., for the discovery and synthesis of semiconductor nanocrystals, also termed quantum dots, that exhibit size-dependent physicochemical properties enabled by quantum size effects. This feature article summarizes the main milestones of the discoveries and developments of quantum dots that paved the road to their versatile applications in solid-state lighting, display technology, energy conversion, medical diagnostics, bioimaging, and image-guided surgery. KW - Quantum dots KW - Semiconductor nanocrystals KW - Luminescence KW - Quantitative spectroscopy KW - Quantum yield KW - Advanced nanomaterials KW - Quality assurance KW - Energy transfer PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597843 DO - https://doi.org/10.1007/s00216-024-05225-9 VL - 2024 SP - 1 EP - 11 PB - Springer CY - Cham AN - OPUS4-59784 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, L. A1 - Hsiao, I-L. A1 - Ebisch, Maximilian A1 - Vidmar, J. A1 - Dreiack, N. A1 - Böhmert, L. A1 - Stock, V. A1 - Braeuning, A. A1 - Loeschner, K. A1 - Laux, P. A1 - Thünemann, Andreas A1 - Lampen, A. A1 - Sieg, H. T1 - The presence of iron oxide nanoparticles in the food pigment E172 N2 - Iron oxides used as food colorants are listed in the European Union with the number E172. However, there are no specifications concerning the fraction of nanoparticles in these pigments. Here, seven E172 products were thoroughly characterized. Samples of all colors were analyzed with a Broad spectrum of methods to assess their physico-chemical properties. Small-Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), zeta-potential, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), X-ray diffraction (XRD), Brunauer-Emmett-Teller analysis (BET), Asymmetric Flow Field-Flow Fractionation (AF4) and in vitro cell viability measurements were used. Nanoparticles were detected in all E172 samples by TEM or SAXS measurements. Quantitative results from both methods were comparable. Five pigments were evaluated by TEM, of which four had a size median below 100 nm, while SAXS showed a size median below 100 nm for six evaluated pigments. Therefore, consumers May be exposed to iron oxide nanoparticles through the consumption of food pigments. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle PY - 2020 DO - https://doi.org/10.1016/j.foodchem.2020.127000 VL - 327 SP - 127000 PB - Elsevier Ltd. AN - OPUS4-50810 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tarantini, A. A1 - Wegner, Karl David A1 - Dussert, F. A1 - Sarret, G. A1 - Beal, D. A1 - Mattera, L. A1 - Lincheneau, C. A1 - Proux, O. A1 - Truffier-Boutry, D. A1 - Moriscot, C. A1 - Gallet, B. A1 - Jouneau, P.-H. A1 - Reiss, P. A1 - Carriere, M. T1 - Physicochemical alterations and toxicity of InP alloyed quantum dots aged in environmental conditions: A safer by design evaluation N2 - Due to their unique optical properties, quantum dots (QDs) are used in a number of optoelectronic devices and are forecasted to be used in the near future for biomedical applications. The most popular QD composition consists of cadmium selenide (CdSe) or cadmium telluride (CdTe), which has been shown to pose health risks due to the release of toxic cadmium (Cd) ions. Due to similar optical properties but lower intrinsic toxicity, indium phosphide (InP) QDs have been proposed as a safer alternative. Nevertheless, investigations regarding their safety and possible toxicological effects are still in their infancy. The fate and toxicity of seven different water-dispersible indium (In) based QDs, either pristine or after ageing in a climatic chamber, was evaluated. The core of these QDs was composed of indium, zinc and phosphorus (InZnP) or indium, zinc, phosphorus and sulfur (InZnPS). They were assessed either as core-only or as core-shell QDs, for which the core was capped with a shell of zinc, selenium and sulfur (Zn(Se,S)). Their Surface was functionalized using either penicillamine or glutathione. In their pristine form, these QDs showed essentially no cytotoxicity. The particular case of InZnPS QD showed that core-shell QDs were less cytotoxic than core-only QDs. Moreover, surface functionalization with either penicillamine or glutathione did not appreciably influence cytotoxicity but affected QD stability. These QDs did not lead to over-accumulation of reactive oxygen species in exposed cells, or to any oxidative damage to cellular DNA. However, accelerated weathering in a climatic chamber led to QD precipitation and degradation, together with significant cytotoxic effects. Ageing led to dissociation of IneP and ZneS bonds, and to complexation of In Zn ions with carboxylate and/or phosphate moieties. These results show that InZnP and InZnPS alloyed QDs are safer alternatives to CdSe QDs. They underline the necessity to preserve as much as possible the structural integrity of QDs, for instance by developing more robust shells, in order to ensure their safety for future applications. KW - Indium phosphide KW - Safe by design KW - Toxicity KW - EXAFS PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-483070 DO - https://doi.org/10.1016/j.impact.2019.100168 VL - 14 SP - 100168-1 EP - 100168-13 PB - Elsevier AN - OPUS4-48307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chowdhary, S. A1 - Moschner, J. A1 - Mikolajczak, D. J. A1 - Becker, M. A1 - Thünemann, Andreas A1 - Kästner, Claudia A1 - Klemczak, D. A1 - Stegemann, A.-K. A1 - Böttcher, C. A1 - Metrangolo, P. A1 - Netz, R. R. A1 - Koksch, B. T1 - The Impact of Halogenated Phenylalanine Derivatives on NFGAIL Amyloid Formation N2 - The hexapeptide hIAPP22–27 (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild‐type hIAPP′s toxicity to β‐cell death. In amyloid research, the role of hydrophobic and aromatic‐aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic‐aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues. We used thioflavin T staining, transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS) to study the impact of side‐chain halogenation on NFGAIL amyloid formation kinetics. Our data revealed a synergy between aggregation behavior and hydrophobicity of the phenylalanine residue. This study introduces systematic fluorination as a toolbox to further investigate the nature of the amyloid self‐assembly process. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Nanostructure KW - Peptide KW - Amyloid PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518632 DO - https://doi.org/10.1002/cbic.202000373 VL - 21 IS - 24 SP - 3544 EP - 3554 PB - Wiley CY - Weinheim AN - OPUS4-51863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wegner, Karl David A1 - Dussert, F. A1 - Truffier-Boutry, D. A1 - Benayad, A. A1 - Beal, D. A1 - Mattera, L. A1 - Ling, W. L. A1 - Carrière, M. A1 - Reiss, P. T1 - Influence of the Core/Shell Structure of Indium Phosphide Based Quantum Dots on Their Photostability and Cytotoxicity N2 - With the goal to improve their photostability, InP-based QDs are passivated with three types of inorganic shells, namely (i) a gradient ZnSexS1−x shell, (ii) an additional ZnS shell on top of the gradient shell with two different thicknesses (core/shell/shell, CSS), (iii) an alumina coating on top of ZnS. All three systems have photoluminescence Quantum yields (PLQY) > 50%and similar PL decay times (64–67 ns). To assess their photostability they are incorporated into a transparent poly (methyl methacrylate) (PMMA) matrix and exposed to continuous irradiation with simulated sunlight in a climate chamber. The alumina coated core/shell system exhibits the highest stability in terms of PLQY Retention as well as the lowest shift of the PL maximum and lowest increase of the PL linewidth, followed by the CSS QDs and finally the gradient shell system. By means of XPS studies we identify the degradation of the ZnS outer layer and concomitant xidation of the emissive InZnP core as the main origins of degradation in the gradient structure. These modifications do not occur in the case of the alumina-capped sample, which exhibits excellent chemical stability. The gradient shell and CSS systems could be transferred to the aqueous phase using surface ligand exchange with penicillamine. Cytotoxicity studies on human primary keratinocytes revealed that exposure for 24 h to 6.25–100 nM of QDs did not affect cell viability. However, a trend toward reduced cell proliferation is observed for higher concentrations of gradient shell and CSS QDs with a thin ZnS shell, while CSS QDs with a thicker ZnS shell do not exhibit any impact. KW - Indium phosphide KW - Quantum dots KW - Cytotoxicity KW - Photostability PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-494249 DO - https://doi.org/10.3389/fchem.2019.00466 VL - 7 SP - Article Number: 466 PB - Frontiers Media SA AN - OPUS4-49424 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, L. A1 - Hoche, E. A1 - Stock, V. A1 - Böhmert, L. A1 - Braeuning, A. A1 - Thünemann, Andreas A1 - Sieg, H. T1 - Intestinal and hepatic effects of iron oxide nanoparticles N2 - Iron oxide nanoparticles gain increasing attention due to their broad industrial use. However, safety concerns exist since their effects on human cells are still under investigation. The presence of iron oxide nanoparticles in the food pigment E172 has been shown recently. Here, we studied four iron oxide nanoparticles, one food pigment E172 and the ionic control FeSO4 regarding dissolution in biological media, uptake and transport, and cellular effects in vitro in human intestinal Caco-2 and HepaRG hepatocarcinoma cells. The iron oxide nanoparticles passed the gastrointestinal passage without dissolution and reached the intestine in the form of particles. Minor uptake was seen into Caco-2 cells but almost no transport to the basolateral site was detected for any of the tested particles. HepaRG cells showed higher particle uptake. Caco-2 cells showed no alterations in reactive oxygen species production, apoptosis, or mitochondrial membrane potential, whereas two particles induced apoptosis in HepaRG cells, and one altered mitochondrial membrane potential at non-cytotoxic concentrations. No correlation between physicochemical particle characteristics and cellular effects was observed, thus emphasizing the Need for case-by-case assessment of iron oxide nanoparticles. KW - Nanoparticles PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521651 DO - https://doi.org/10.1007/s00204-020-02960-7 VL - 95 IS - 3 SP - 895 EP - 905 PB - Springer AN - OPUS4-52165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -