TY - JOUR A1 - Schlaad, H. A1 - Müller, A. H. E. A1 - Kolshorn, H. A1 - Krüger, Ralph-Peter T1 - Mechanism of anionic polymerization of (meth)acrylates in the presence of aluminium alkyls PY - 1995 SN - 0170-0839 SN - 1436-2449 VL - 35 SP - 169 EP - 176 PB - Springer CY - Berlin AN - OPUS4-2144 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spickermann, J. A1 - Martin, K. A1 - Räder, H.J. A1 - Müllen, K. A1 - Schlaad, H. A1 - Müller, A. H. E. A1 - Krüger, Ralph-Peter T1 - Quantitative analysis of broad molecular weight distributions obtained by MALDI-TOF mass spectrometry PY - 1996 SN - 1469-0667 SN - 1356-1049 SN - 1365-0718 IS - 2 SP - 161 EP - 165 PB - IM Publications CY - Chichester AN - OPUS4-2153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schlaad, H. A1 - Müller, A. A1 - Spickermann, J. A1 - Räder, H. A1 - Krüger, Ralph-Peter T1 - Quantitative Analysis of Molecular Weight Distribution Obtained by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS) T2 - 2nd International Conference on Molecular Mass Characterization of Synthetic and Natural Polymers CY - Bradford, England, UK DA - 1996-04-01 PY - 1996 CY - Bradford AN - OPUS4-2218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kukula, H. A1 - Schlaad, H. A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana T1 - Improved Synthesis and Characterization of w-Primary Amino-Functional Polystyrenes and Polydienes PY - 2002 DO - https://doi.org/10.1021/ma0204397 SN - 0024-9297 SN - 1520-5835 VL - 35 IS - 18 SP - 7157 EP - 7160 PB - American Chemical Society CY - Washington, DC AN - OPUS4-1659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koshkina, Olga A1 - Westmeier, D. A1 - Lang, Thomas A1 - Bantz, C. A1 - Hahlbrock, A. A1 - Würth, Christian A1 - Resch-Genger, Ute A1 - Braun, Ulrike A1 - Thiermann, Raphael A1 - Weise, C. A1 - Eravci, M. A1 - Mohr, B. A1 - Schlaad, H. A1 - Stauber, R. H. A1 - Docter, D. A1 - Bertin, Annabelle A1 - Maskos, M. T1 - Tuning the surface of nanoparticles: Impact of poly(2-ethyl-2-oxazoline) on protein adsorption in serum and cellular uptake N2 - Due to the adsorption of biomolecules, the control of the biodistribution of nanoparticles is still one of the major challenges of nanomedicine. Poly(2-ethyl-2-oxazoline) (PEtOx) for surface modification of nanoparticles is applied and both protein adsorption and cellular uptake of PEtOxylated nanoparticles versus nanoparticles coated with poly(ethylene glycol) (PEG) and non-coated positively and negatively charged nanoparticles are compared. Therefore, fluorescent poly(organosiloxane) nanoparticles of 15 nm radius are synthesized, which are used as a scaffold for surface modification in a grafting onto approach. With multi-angle dynamic light scattering, asymmetrical flow field-flow fractionation, gel electrophoresis, and liquid chromatography-mass spectrometry, it is demonstrated that protein adsorption on PEtOxylated nanoparticles is extremely low, similar as on PEGylated nanoparticles. Moreover, quantitative microscopy reveals that PEtOxylation significantly reduces the non-specific cellular uptake, particularly by macrophage-like cells. Collectively, studies demonstrate that PEtOx is a very effective alternative to PEG for stealth modification of the surface of nanoparticles. KW - Poloxazolines KW - Protein corona KW - Cellular uptake PY - 2016 DO - https://doi.org/10.1002/mabi.201600074 SN - 1616-5187 SN - 1616-5195 VL - 16 IS - 9 SP - 1287 EP - 1300 AN - OPUS4-37369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Casse, O. A1 - Shkilnyy, A. A1 - Linders, J. A1 - Mayer, C. A1 - Häussinger, D. A1 - Völkel, A. A1 - Thünemann, Andreas A1 - Dimova, R. A1 - Cölfen, H. A1 - Meier, W. A1 - Schlaad, H. A1 - Taubert, A. T1 - Solution behavior of double-hydrophilic block copolymers in dilute aqueous solution N2 - The self-assembly of double-hydrophilic poly(ethylene oxide)–poly(2-methyl-2-oxazoline) diblock copolymers in water has been studied. Isothermal titration calorimetry, small-angle X-ray scattering, and analytical ultracentrifugation suggest that only single polymer chains are present in solution. In contrast, light scattering and transmission electron microscopy detect aggregates with radii of ca. 100 nm. Pulsed field gradient NMR spectroscopy confirms the presence of aggregates, although only 2% of the polymer chains undergo aggregation. Water uptake experiments indicate differences in the hydrophilicity of the two blocks, which is believed to be the origin of the unexpected aggregation behavior (in accordance with an earlier study by Ke et al. [Macromolecules2009, 42, 5339–5344]). The data therefore suggest that even in double-hydrophilic block copolymers, differences in hydrophilicity are sufficient to drive polymer aggregation, a phenomenon that has largely been overlooked or ignored so far. KW - Nanotechnology KW - Small-angle X-ray scatering KW - SAXS PY - 2012 DO - https://doi.org/10.1021/ma300621g SN - 0024-9297 SN - 1520-5835 VL - 45 IS - 11 SP - 4772 EP - 4777 PB - American Chemical Society CY - Washington, DC AN - OPUS4-26072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thünemann, Andreas A1 - Schütt, D. A1 - Sachse, R. A1 - Schlaad, H. A1 - Möhwald, H. T1 - Complexes of Poly(ethylene oxide)-block-Poly(L-glutamate) and Diminazene KW - Polymers KW - Nanoparticles KW - Proteins PY - 2006 SN - 0743-7463 SN - 1520-5827 VL - 22 IS - 5 SP - 2323 EP - 2328 PB - American Chemical Society CY - Washington, DC AN - OPUS4-12117 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koshkina, Olga A1 - Lang, Thomas A1 - Thiermann, R. A1 - Docter, D. A1 - Stauber, R.H. A1 - Secker, C. A1 - Schlaad, H. A1 - Weidner, Steffen A1 - Mohr, B. A1 - Maskos, M. A1 - Bertin, Annabelle T1 - Temperature-triggered protein adsorption on polymer-coated nanoparticles in serum N2 - The protein corona, which forms on the nanoparticle's surface in most biological media, determines the nanoparticle’s physicochemical characteristics. The formation of the protein corona has a significant impact on the biodistribution and clearance of nanoparticles in vivo. Therefore, the ability to influence the formation of the protein corona is essential to most biomedical applications, including drug delivery and imaging. In this study, we investigate the protein adsorption on nanoparticles with a hydrodynamic radius of 30 nm and a coating of thermoresponsive poly(2-isopropyl-2-oxazoline) in serum. Using multiangle dynamic light scattering (DLS) we demonstrate that heating of the nanoparticles above their phase separation temperature induces the formation of agglomerates, with a hydrodynamic radius of 1 µm. In serum, noticeably stronger agglomeration occurs at lower temperatures compared to serum-free conditions. Cryogenic transmission electron microscopy (cryo-TEM) revealed a high packing density of agglomerates when serum was not present. In contrast, in the presence of serum, agglomerated nanoparticles were loosely packed, indicating that proteins are intercalated between them. Moreover, an increase in protein content is observed upon heating, confirming that protein adsorption is induced by the alteration of the surface during phase separation. After cooling and switching the surface back, most of the agglomerates were dissolved and the main fraction returned to the original size of approximately 30 nm as shown by asymmetrical flow-field flow fractionation (AF-FFF) and DLS. Furthermore, the amounts of adsorbed proteins are similar before and after heating the nanoparticles to above their phase-separation temperature. Overall, our results demonstrate that the thermoresponsivity of the polymer coating enables turning the corona formation on nanoparticles on and off in situ. As the local heating of body areas can be easily done in vivo, the thermoresponsive coating could potentially be used to induce the agglomeration of nanoparticles and proteins and the accumulation of nanoparticles in a targeted body region. PY - 2015 DO - https://doi.org/10.1021/acs.langmuir.5b00537 SN - 0743-7463 SN - 1520-5827 VL - 31 IS - 32 SP - 8873 EP - 8881 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Secker, C. A1 - Brosnan, S.M. A1 - Limberg, F.R.P. A1 - Braun, Ulrike A1 - Trunk, M. A1 - Strauch, P. A1 - Schlaad, H. T1 - Thermally induced crosslinking of poly(N-propargyl glycine) N2 - As polypeptoids become increasingly popular, they present a more soluble and processable alternative to natural and synthetic polypeptides; the breadth of their potential functionality slowly comes into focus. This report analyzes the ability of an alkyne-functionalized polypeptoid, poly(N-propargyl glycine), to crosslink upon heating. The crosslinking process is analyzed by thermal analysis (differential scanning calorimetry and thermogravimetric analysis), Fourier-transform infrared, electron paramagnetic resonance, and solid-state NMR spectroscopy. While a precise mechanism cannot be confidently assigned, it is clear that the reaction proceeds by a radical mechanism that exclusively involves the alkyne functionality, which, upon crosslinking, yields alkene and aromatic products. KW - Fourier-transform infrared KW - Metal-free crosslinking KW - Polypeptoid KW - Propargyl KW - Solid-state NMR PY - 2015 DO - https://doi.org/10.1002/macp.201500223 SN - 1022-1352 SN - 1521-3935 VL - 216 IS - 21 SP - 2080 EP - 2085 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-35265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schlaad, H. A1 - You, L. A1 - Sigel, R. A1 - Smarsly, B. A1 - Heydenreich, M. A1 - Mantion, Alexandre A1 - Masic, A. T1 - Glycopolymer vesicles with an asymmetric membrane KW - Glycopolymer vesicle PY - 2009 DO - https://doi.org/10.1039/b820887e SN - 0022-4936 SN - 0009-241x SN - 1359-7345 SN - 1364-548x SP - 1478 EP - 1480 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-19581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -