TY - CONF A1 - Thünemann, Andreas T1 - Nanoplastics Aqueous Dispersions as Polymer Reference Materials for a Sustainable Future N2 - The undesirable presence of micro and nanoplastics in our environment and in food is now common knowledge. However, it is unclear whether serious dangers and risks are posed by nanoplastics. A scientifically based reliable determination of the type and quantity of nanoplastics in complex matrices is of considerable importance for the future sustainable use of polymers. Here, reference materials help in the determination of nanoplastics. In particular, colloidally stable aqueous dispersions of nanoplastics appear suitable for this purpose. We report on the current status of the development of nanoplastics as reference materials. A detailed example of reference materials for characterizing nanoplastics is provided in the form of aqueous dispersion of polypropylene. The nanoplastics samples are colloidal stable for at least two years at ambient conditions. A low zeta potential of -35 mV at a neutral pH value provides stability. An overview of their colloidal properties in different environmental conditions is presented. Next, polyethylene nanoplastics will be compared to polypropylene nanoplastics. Nanoplastics consisting of poly(ethylene terephthalate) will be discussed and finally, we report on poly(L-lactic acid) as a typical and important representative of biodegradable polymers. T2 - POLYMERS FOR A SUSTAINABLE FUTURE: Biennial Meeting of the GDCh-Division of Macromolecular Chemistry CY - Dresden, Germany DA - 16.09.2024 KW - Reference Material PY - 2024 AN - OPUS4-61079 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rudolph, C. A1 - Sieverling, N. A1 - Schillinger, U. A1 - Lesina, E. A1 - Plank, C. A1 - Thünemann, Andreas A1 - Schönberger, H. A1 - Rosenecker, J. T1 - Thyroid hormone (T3)-modification of polyethyleneglycol (PEG)-polyethyleneimine (PEI) graft copolymers for improved gene delivery to hepatocytes N2 - Targeting of gene vectors to liver hepatocytes could offer the opportunity to cure various acquired and inherited diseases. Efficient gene delivery to the liver parenchyma has been obscured from efficient targeting of hepatocytes. Here we show that the thyroid hormone, triiodothyronine (T3), can be used to improve the gene transfer efficiency of nonviral gene vectors to hepatocytes in vitro and to the liver of mice in vivo. T3 conjugated to the distal ends of fluorescent labeled PEG-g-dextran resulted in T3-specific cellular endosomal uptake into the hepatocellular cell line HepG2. PEG-g-PEI graft copolymers with increasing molar PEG-ratios were synthesized, complexed with plasmid DNA, and transfected into HepG2 or HeLa cells. Gene transfer efficiency decreased as the number of PEG blocks increased. T3 conjugation to PEI and the distal ends of PEG blocks resulted in T3 specific gene transfer in HepG2 cells as evidenced by reduction of gene transfer efficiency after pre-incubation of cells with excess of T3. In vivo application of T3-PEG-g-PEI based gene vectors in mice after tail vein injection resulted in a significantly 7-fold increase of gene expression in the liver compared with PEG-g-PEI based gene vectors. KW - Nonviral KW - PEI KW - Gene transfer KW - Thyroid hormone KW - T3 KW - Liver PY - 2007 SN - 0142-9612 VL - 28 IS - 10 SP - 1900 EP - 1911 PB - Elsevier CY - Oxford AN - OPUS4-14521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Orts Gil, Guillermo A1 - Natte, Kishore A1 - Thiermann, Raphael A1 - Girod, Matthias A1 - Rades, Steffi A1 - Kalbe, Henryk A1 - Thünemann, Andreas A1 - Maskos, M. A1 - Österle, Werner T1 - On the role of surface composition and curvature on biointerface formation and colloidal stability of nanoparticles in a protein-rich model system N2 - The need for a better understanding of nanoparticle–protein interactions and the mechanisms governing the resulting colloidal stability has been emphasised in recent years. In the present contribution, the short and long term colloidal stability of silica nanoparticles (SNPs) and silica–poly(ethylene glycol) nanohybrids (Sil–PEG) have been scrutinised in a protein model system. Well-defined silica nanoparticles are rapidly covered by bovine serum albumin (BSA) and form small clusters after 20 min while large agglomerates are detected after 10 h depending on both particle size and nanoparticle–protein ratio. Oppositely, Sil–PEG hybrids present suppressive protein adsorption and enhanced short and long term colloidal stability in protein solution. No critical agglomeration was found for either system in the absence of protein, proving that instability found for SNPs must arise as a consequence of protein adsorption and not to high ionic environment. Analysis of the small angle X-ray scattering (SAXS) structure factor indicates a short-range attractive potential between particles in the silica-BSA system, which is in good agreement with a protein bridging agglomeration mechanism. The results presented here point out the importance of the nanoparticle surface properties on the ability to adsorb proteins and how the induced or depressed adsorption may potentially drive the resulting colloidal stability. KW - Nanoparticles KW - Protein corona KW - Biointerface KW - BSA KW - PEG KW - Colloidal stability PY - 2013 DO - https://doi.org/10.1016/j.colsurfb.2013.02.027 SN - 0927-7765 SN - 1873-4367 VL - 108 SP - 110 EP - 119 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-30100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haase, A. A1 - Arlinghaus, H. F. A1 - Tentschert, J. A1 - Jungnickel, H. A1 - Graf, P. A1 - Mantion, Alexandre A1 - Draude, F. A1 - Galla, S. A1 - Plendl, J. A1 - Goetz, M.E. A1 - Masic, A. A1 - Meier, W. A1 - Thünemann, Andreas A1 - Taubert, A. A1 - Luch, A. T1 - Application of laser postionization secondary neutral mass spectrometry / time-of-flight secondary ion mass spectrometry in nanotoxicology: Visualization of nanosilver in human macrophages and cellular responses N2 - Silver nanoparticles (SNP) are the subject of worldwide commercialization because of their antimicrobial effects. Yet only little data on their mode of action exist. Further, only few techniques allow for visualization and quantification of unlabeled nanoparticles inside cells. To study SNP of different sizes and coatings within human macrophages, we introduce a novel laser postionization secondary neutral mass spectrometry (Laser-SNMS) approach and prove this method superior to the widely applied confocal Raman and transmission electron microscopy. With time-of-flight secondary ion mass spectrometry (TOF-SIMS) we further demonstrate characteristic fingerprints in the lipid pattern of the cellular membrane indicative of oxidative stress and membrane fluidity changes. Increases of protein carbonyl and heme oxygenase-1 levels in treated cells confirm the presence of oxidative stress biochemically. Intriguingly, affected phagocytosis reveals as highly sensitive end point of SNP-mediated adversity in macrophages. The cellular responses monitored are hierarchically linked, but follow individual kinetics and are partially reversible. KW - Nanosilver KW - Laser-SNMS KW - TOF-SIMS KW - Confocal Raman microscopy KW - Oxidative stress KW - Protein carbonyls PY - 2011 DO - https://doi.org/10.1021/nn200163w SN - 1936-0851 VL - 5 IS - 4 SP - 3059 EP - 3068 PB - ACS Publ. CY - Washington, DC, USA AN - OPUS4-23656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Draude, F. A1 - Galla, S. A1 - Pelster, A. A1 - Tentschert, J. A1 - Jungnickel, H. A1 - Haase, A. A1 - Mantion, Alexandre A1 - Thünemann, Andreas A1 - Taubert, A. A1 - Luch, A. A1 - Arlinghaus, H. F. T1 - ToF-SIMS and laser-SNMS analysis of macrophages after exposure to silver nanoparticles N2 - Silver nanoparticles (SNPs) are among the most commercialized nanoparticles because of their antibacterial effects. Besides being employed, e.g. as a coating material for sterile surfaces in household articles and appliances, the particles are also used in a broad range of medical applications. Their antibacterial properties make SNPs especially useful for wound disinfection or as a coating material for prostheses and surgical instruments. Because of their optical characteristics, the particles are of increasing interest in biodetection as well. Despite the widespread use of SNPs, there is little knowledge of their toxicity. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and laser post-ionization secondary neutral mass spectrometry (Laser-SNMS) were used to investigate the effects of SNPs on human macrophages derived from THP-1 cells in vitro. For this purpose, macrophages were exposed to SNPs. The SNP concentration ranges were chosen with regard to functional impairments of the macrophages. To optimize the analysis of the macrophages, a special silicon wafer sandwich preparation technique was employed; ToF-SIMS was employed to characterize fragments originating from macrophage cell membranes. With the use of this optimized sample preparation method, the SNP-exposed macrophages were analyzed with ToF-SIMS and with Laser-SNMS. With Laser-SNMS, the three-dimensional distribution of SNPs in cells could be readily detected with very high efficiency, sensitivity, and submicron lateral resolution. We found an accumulation of SNPs directly beneath the cell membrane in a nanoparticular state as well as agglomerations of SNPs inside the cells. KW - Laser-SNMS KW - ToF-SIMS KW - Life sciences KW - Imaging KW - Nanoparticles KW - Three-dimensional depth profiling KW - Silver nanoparticle PY - 2013 DO - https://doi.org/10.1002/sia.4902 SN - 0142-2421 SN - 1096-9918 VL - 45 IS - 1 SP - 286 EP - 289 PB - Wiley CY - Chichester AN - OPUS4-27585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - López, J.P. A1 - Kraus, Werner A1 - Reck, Günter A1 - Thünemann, Andreas A1 - Kurth, D.G. T1 - Alternating perpendicular 1-D channels in the supramolecular structure of the copper(II) complex [Cu(pyterpy)2](PF6)2 . CH3OH . 0.5 CH2Cl2 (pyterpy = 4'-(4'''-pyridyl)-2,2':6',2''-terpyridine) KW - 4´-(4´´´-pyridyl)-2,2´:6´2´´-terpyridine KW - Copper complexes KW - Crystal structure KW - Supramolecular chemistry KW - Pi-pi stacking PY - 2005 SN - 1387-7003 VL - 8 SP - 281 EP - 284 PB - Elsevier CY - Amsterdam AN - OPUS4-6301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lichtenstein, D. A1 - Meyer, T. A1 - Böhmert, L. A1 - Juling, S. A1 - Fahrenson, C. A1 - Selve, S. A1 - Thünemann, Andreas A1 - Meijer, J. A1 - Estrela-Lopis, I. A1 - Braeuning, A. A1 - Lampen, A. T1 - Dosimetric quantification of coating-related uptake of silver nanoparticles N2 - The elucidation of mechanisms underlying the cellular uptake of nanoparticles (NPs) is an important topic in nanotoxicological research. Most studies dealing with silver NP uptake provide only qualitative data about internalization efficiency and do not consider NP-specific dosimetry. Therefore, we performed a comprehensive comparison of the cellular uptake of differently coated silver NPs of comparable size in different human intestinal Caco-2 cell-derived models to cover also the influence of the intestinal mucus barrier and uptake-specialized M-cells. We used a combination of the Transwell system, transmission electron microscopy, atomic absorption spectroscopy, and ion beam microscopy techniques. The computational in vitro sedimentation, diffusion, and dosimetry (ISDD) model was used to determine the effective dose of the particles in vitro based on their individual physicochemical characteristics. Data indicate that silver NPs with a similar size and shape show coating-dependent differences in their uptake into Caco-2 cells. The internalization of silver NPs was enhanced in uptake-specialized M-cells while the mucus did not provide a substantial barrier for NP internalization. ISDD modeling revealed a fivefold underestimation of dose–response relationships of NPs in in vitro assays. In summary, the present study provides dosimetry-adjusted quantitative data about the influence of NP coating materials in cellular uptake into human intestinal cells. Underestimation of particle effects in vitro might be prevented by using dosimetry models and by considering cell models with greater proximity to the in vivo situation, such as the M-cell model. KW - Silver nanoparticles KW - Small-angle X-ray scattering KW - Saxs PY - 2017 DO - https://doi.org/10.1021/acs.langmuir.7b01851 SN - 0743-7463 VL - 33 IS - 45 SP - 13087 EP - 13097 PB - Americal Chemical Society AN - OPUS4-42875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, L. A1 - Saloga, Patrick E. J. A1 - Stock, V. A1 - Böhmert, L. A1 - Braeuning, A. A1 - Thünemann, Andreas A1 - Lampen, A. A1 - Sieg, H. T1 - Environmental impact of ZnO nanoparticles evaluated by in vitro simulated digestion N2 - ZnO nanoparticles are found in different food and consumer products, and their toxicological effects are still under investigation. It is therefore important to understand their behavior in the gastrointestinal tract. Here, we used an in vitro model to assess the physicochemical fate of ZnO nanoparticles during the digestive process in artificial saliva, stomach juice, and intestinal juice. Atomic absorption spectrometry and small-angle X-ray scattering were employed to investigate two ZnO nanomaterials, one intensively characterized reference material and soluble ZnCl2 in a broad range of concentrations between 25 and 1000 μg/mL in the intestinal fluid. Because food components may influence the behavior of nanomaterials in the gastrointestinal tract, starch, milk powder, and olive oil were used to mimic carbohydrates, protein, and fat, respectively. Additionally, ion release of all Zn species was assessed in cell culture media and compared to artificial intestinal juice to investigate relevance of typical cell culture conditions in ZnO nanotoxicology. ZnCl2 as well as the ZnO species were present as particles in artificial saliva but were solubilized completely in the acidic stomach juice. Interestingly, in the intestinal fluid a concentration-independent de novo formation of particles in the nanoscale range was shown. This was the case for all particles as well as for ZnCl2, regardless of the concentration used. Neither of the food components affected the behavior of any Zn species. On the contrary, all Zn species showed a Zn-concentration-dependent ion release in common cell culture medium. This questions the suitability of cell culture studies to investigate the effect of ZnO nanoparticles on intestinal cells. Our results show that Zn-containing nanoparticles reach the intestine. This underlines the importance of determining the influence of the test environment on nanoparticle fate. KW - SAXS KW - Digestion KW - Zinc oxide KW - Nanoparticles PY - 2020 DO - https://doi.org/10.1021/acsanm.9b02236 VL - 3 IS - 1 SP - 724 EP - 733 AN - OPUS4-50288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lutz, J.-F. A1 - Nehring, R. A1 - Thünemann, Andreas T1 - Solution Self-Assembly of Synthetic Copolymers bearing Complementary Nucleic Acid Funtionalities KW - DNA KW - Living polymerization KW - ATRP KW - Copolymers PY - 2005 SN - 0032-3934 VL - 46 IS - 2 SP - 397 EP - 398 PB - American Chemical Society CY - Newark, NJ AN - OPUS4-10535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schott, M. A1 - Szczerba, Wojciech A1 - Posset, U. A1 - Vuk, A.S. A1 - Beck, M. A1 - Riesemeier, Heinrich A1 - Thünemann, Andreas A1 - Kurth, D. G. T1 - In operando XAFS experiments on flexible electrochromic devices based on Fe(II)-metallo-supramolecular polyelectrolytes and vanadium oxides N2 - Flexible electrochromic devices (ECDs) based on Fe(II)-metallo-supramolecular polyelectrolytes (Fe-MEPE) and vanadium oxide are studied in operando by means of x-ray absorption fine structure (XAFS) spectroscopy. The ECDs are blue-purple in the colored state at 0.0 V and become light yellow when a voltage of 1.6 V is applied. The XAFS studies at the K-edge of Fe(II) reveals that the absorption edge is shifted toward higher energies by 1.8 eV in the transparent state. Comparison of two different ECDs and different charge cycles demonstrates the reversibility and repeatability of the process. We attribute the shift to a charge transfer and a change of oxidation state of the ions from Fe2+ to Fe3+. The transition is not accompanied by a noticeable structural change of the octahedral coordination geometry as confirmed by analysis of the extended x-ray absorption fine structure (EXAFS) data. (C) 2015 Elsevier B.V. All rights reserved. KW - Metallo-supramolecular polyelectrolytes KW - Vanadium oxide KW - Electrochromism KW - Electrochromic device KW - Cyclic voltammetry KW - XAFS PY - 2016 DO - https://doi.org/10.1016/j.solmat.2015.10.015 SN - 0927-0248 VL - 147 SP - 61 EP - 67 PB - Elsevier B.V. CY - Amsterdam [u.a.] AN - OPUS4-35251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Juling, S. A1 - Böhmert, L. A1 - Lichtenstein, D. A1 - Oberemm, A. A1 - Creutzenberg, O. A1 - Thünemann, Andreas A1 - Braeuning, A. A1 - Lampen, A. T1 - Comparative proteomic analysis of hepatic effects induced by nanosilver, silver ions and nanoparticle coating in rats N2 - The presence of nano-scaled particles in food and food-related products has drawn attention to the oral uptake of nanoparticles and their interactions with biological systems. In the present study, we used a toxicoproteomics approach to allow for the untargeted experimental identification and comparative analysis of cellular Responses in rat liver after repeated-dose treatment with silver nanoparticles, ions, and the coating matrix used for particle stabilization. The proteomic analysis revealed treatment-related effects caused by exposure to silver in particulate and ionic form. Both silver species induced similar patterns of signaling and metabolic alterations. Silver-induced cellular alterations comprised, amongst others, proteins involved in metal homeostasis, oxidative stress response, and energy metabolism. However, we discovered that secondary nano-scaled structures were formed from ionic silver. Furthermore, also the coating matrix alone gave rise to the formation of nano-scaled particles. The present data confirm, complement, and extend previous knowledge on silver toxicity in rodent liver by providing a comprehensive proteomic data set. The observation of secondary particle formation from nonparticle controls underlines the difficulties in separating particle-, ion-, and matrix coating-related effects in biological systems. Awareness of this issue will support proper evaluation of nanotoxicology-related data in the future. KW - Silver nanoparticles KW - Small-angle X-ray scattering KW - SAXS PY - 2018 DO - https://doi.org/10.1016/j.fct.2018.01.056 SN - 0278-6915 SN - 1873-6351 VL - 113 SP - 255 EP - 266 PB - Elsevier AN - OPUS4-44563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lutz, J.-F. A1 - Pfeifer, S. A1 - Chanana, M. A1 - Thünemann, Andreas A1 - Bienert, Ralf T1 - H-Bonding-Directed Self-Assembly of Synthetic Copolymers Containing Nucleobases: Organization and Colloidal Fusion in a Noncompetitive Solvent N2 - The self-organization of random copolymers composed of a nucleobase monomer (either 1-(4-vinylbenzyl)thymine or 9-(4-vinylbenzyl)adenine) and dodecyl methacrylate (DMA) was studied in dilute chloroform solutions. The balance between the molar fractions of the nucleobase monomer (leading to intermolecular H-bonding) and DMA (soluble moiety in chloroform) in the polymer chains was found to be the parameter that principally influences the self-organization. DMA-rich copolymers are molecularly soluble in chloroform, whereas nucleobase-rich copolymers are insoluble in this solvent. Copolymers possessing an equimolar comonomer composition self-assemble into micrometer-sized particles physically cross-linked by intermolecular H-bonds (either thymine-thymine or adenine-adenine interactions, depending on the studied copolymer). Nevertheless, when mixed together, thymine- and adenine-based colloids fuse into thermodynamically stable microspheres cross linked by adenine-thymine interactions. KW - Synthetic polymers KW - Self-organization KW - H-bonding KW - Nucleobases KW - Confocal fluorescence microscopy PY - 2006 DO - https://doi.org/10.1021/la061382a SN - 0743-7463 SN - 1520-5827 VL - 22 IS - 17 SP - 7411 EP - 7415 PB - American Chemical Society CY - Washington, DC AN - OPUS4-12637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -