@article{CzyschMedina‐MontanoZhongetal.2022, author = {Czysch, Christian and Medina-Montano, Carolina and Zhong, Zifu and Fuchs, Alexander and Stickdorn, Judith and Winterwerber, Pia and Schmitt, Sascha and Deswarte, Kim and Raabe, Marco and Scherger, Maximilian and Combes, Francis and De Vrieze, Jana and Kasmi, Sabah and Sandners, Niek N. and Lienenklaus, Stefan and Koynov, Kaloian and R{\"a}der, Hans-Joachim and Lambrecht, Bart N. and David, Sunil A. and Bros, Matthias and Schild, Hansj{\"o}rg and Grabbe, Stephan and De Geest, Bruno G. and Nuhn, Lutz}, title = {Transient Lymph Node Immune Activation by Hydrolysable Polycarbonate Nanogels}, series = {Advanced Functional Materials}, volume = {32}, journal = {Advanced Functional Materials}, number = {35}, doi = {10.1002/adfm.202203490}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287255}, year = {2022}, abstract = {The development of controlled biodegradable materials is of fundamental importance in immunodrug delivery to spatiotemporally controlled immune stimulation but avoid systemic inflammatory side effects. Based on this, polycarbonate nanogels are developed as degradable micellar carriers for transient immunoactivation of lymph nodes. An imidazoquinoline-type TLR7/8 agonist is covalently conjugated via reactive ester chemistry to these nanocarriers. The nanogels not only provide access to complete disintegration by the hydrolysable polymer backbone, but also demonstrate a gradual disintegration within several days at physiological conditions (PBS, pH 6.4-7.4, 37 °C). These intrinsic properties limit the lifetime of the carriers but their payload can still be successfully leveraged for immunological studies in vitro on primary immune cells as well as in vivo. For the latter, a spatiotemporal control of immune cell activation in the draining lymph node is found after subcutaneous injection. Overall, these features render polycarbonate nanogels a promising delivery system for transient activation of the immune system in lymph nodes and may consequently become very attractive for further development toward vaccination or cancer immunotherapy. Due to the intrinsic biodegradability combined with the high chemical control during the manufacturing process, these polycarbonate-based nanogels may also be of great importance for clinical translation.}, language = {en} } @article{StaabLotterMuehleetal.2021, author = {Staab, Torsten E. M. and Lotter, Frank and M{\"u}hle, Uwe and Elsayed, Mohamed and Petschke, Danny and Schubert, Thomas and Ibrahim, Alaa M. and Krause-Rehberg, Reinhard and Kieback, Bernd}, title = {The decomposition process in high-purity Al-1.7 at.\% Cu alloys with trace elements: preservation of quenched-in vacancies by In, Sn and Pb influencing the ​θ′formation}, series = {Journal of Materials Science}, volume = {56}, journal = {Journal of Materials Science}, number = {14}, issn = {1573-4803}, doi = {10.1007/s10853-020-05742-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-269103}, pages = {8717-8731}, year = {2021}, abstract = {Aluminium-copper alloys of the 2xxx type receive their excellent mechanical properties by the formation of copper-rich precipitates during hardening. Size, distribution and crystal structure of the formed precipitates determine the final strength of those alloys. Adding traces of certain elements, which bind to vacancies, significantly influences the decomposition behaviour, i.e. the diffusion of the copper atoms. For high-purity ternary alloys (Al-1.7 at.\% Cu-X), we investigate the interaction of copper and trace element atoms (X=In, Sn, and Pb) with quenched-in vacancies by Positron Annihilation Lifetime Spectroscopy (PALS). By employing Vickers microhardness, Differential Scanning Calorimetry (DSC) and Small Angle X-Ray Scattering (SAXS) we obtain a comprehensive picture of the decomposition process: opposite to predicted binding energies to vacancies by ab-initio calculations we find during ageing at room and elevated temperature a more retarded clustering of copper in the presence of In rather than for Sn additions, while Pb, having the highest predicted binding to vacancies, shows nearly no retarding effect compared to pure Al-Cu. If the latter would be due to a limited solubility of lead, it had to be below 2 ppm. Transmission Electron Microscopy (TEM) as imaging method complements our findings. Annealing the quenched Al-1.7 at.\% Cu-X-alloys containing 100 ppm In or Sn at 150∘C leads to finely distributed θ′-precipitates on the nanoscale, since due to the trace additions the formation temperature of θ′ is lowered by more than 100∘C. According to TEM small agglomerates of trace elements (In, Sn) may support the early nucleation for the θ′-precipitates.}, language = {en} } @article{LehmannBaumannLambovetal.2021, author = {Lehmann, Matthias and Baumann, Maximilian and Lambov, Martin and Eremin, Alexey}, title = {Parallel polar dimers in the columnar self-assembly of umbrella-shaped subphthalocyanine mesogens}, series = {Advanced Functional Materials}, volume = {31}, journal = {Advanced Functional Materials}, number = {38}, doi = {10.1002/adfm.202104217}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256343}, year = {2021}, abstract = {The self-assembly of umbrella-shaped mesogens is explored with subphthalocyanine cores and oligo(thienyl) arms with different lengths in the light of their application as light-harvesting and photoconducting materials. While the shortest arm derivatives self-assemble in a conventional columnar phase with a single mesogen as a repeating unit, the more extended derivatives generate dimers that pile up into liquid crystalline columns. In contrast to the antiparallel arrangement known from single crystals, the present mesogens align as parallel dimers in polar columnar phases as confirmed by X-ray scattering, experimental densities, dielectric spectroscopy, second harmonic generation, alignment, and conductivity studies. UV-vis and fluorescence spectroscopies reveal a broad absorption in the visible range and only weak emission of the Q-band. Thus, these light-collecting molecules forming strongly polar columnar mesophases are attractive for application in the area of photoconductive materials.}, language = {en} } @article{BossertdeBruinGoetzetal.2016, author = {Bossert, Nelli and de Bruin, Donny and G{\"o}tz, Maria and Bouwmeester, Dirk and Heinrich, Doris}, title = {Fluorescence-tunable Ag-DNA biosensor with tailored cytotoxicity for live-cell applications}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, number = {37897}, doi = {10.1038/srep37897}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167482}, year = {2016}, abstract = {DNA-stabilized silver clusters (Ag-DNA) show excellent promise as a multi-functional nanoagent for molecular investigations in living cells. The unique properties of these fluorescent nanomaterials allow for intracellular optical sensors with tunable cytotoxicity based on simple modifications of the DNA sequences. Three Ag-DNA nanoagent designs are investigated, exhibiting optical responses to the intracellular environments and sensing-capability of ions, functional inside living cells. Their sequence-dependent fluorescence responses inside living cells include (1) a strong splitting of the fluorescence peak for a DNA hairpin construct, (2) an excitation and emission shift of up to 120 nm for a single-stranded DNA construct, and (3) a sequence robust in fluorescence properties. Additionally, the cytotoxicity of these Ag-DNA constructs is tunable, ranging from highly cytotoxic to biocompatible Ag-DNA, independent of their optical sensing capability. Thus, Ag-DNA represents a versatile live-cell nanoagent addressable towards anti-cancer, patient-specific and anti-bacterial applications.}, language = {en} }