TY - CONF A1 - Bertin, Annabelle A1 - Asadujjaman, Asad T1 - Phase transition and aggregation behavior of thermoresponsive copolymer poly(acrylamide-co-acrylonitrile) N2 - Thermoresponsive polymers have shown great potential in applications such as bioseparation, drug delivery and diagnostic. Only few thermoresponsive polymers that present an upper critical solution temperature (UCST), i.e. phase separate from solution upon cooling, in a relevant temperature range have been reported so far. Moreover, the most studied UCST type polymers namely polybetaines are difficult to use under physiological conditions, which significantly restricts their potential applications. Therefore, UCST polymers with sharp and robust phase transition in physiological conditions (in the presence of salts, etc.) are highly needed in order to extend the range of applications of this class of polymers. A robust UCST-type copolymer of acrylamide (AAm) and acrylonitrile (AN) (poly(AAm-co-AN)) was prepared by reversible addition fragmentation chain transfer (RAFT) polymerization and its thermo-induced aggregation behavior in aqueous media was studied by turbidimetry, dynamic and static light scattering. At temperature below the UCST, the poly(AAm-co-AN) copolymer chains were aggregated together. The aggregate size was found to be larger with increasing AN contents and became smaller upon dilution of the copolymer solutions. While above the UCST, the poly(AAm-co-AN) copolymer chains were expanded and weekly associated in solution. The association between the copolymer chains formed smaller aggregates with increasing the AN contents or the concentration of the solutions. A model is proposed to explain such association-aggregation behavior of the poly(AAm-co-AN) copolymer depending on the AN contents and concentration of the solutions. T2 - Biennial meeting GDCh-Division of Macromolecular Chemistry CY - Halle, Germany DA - 11.09.2016 KW - Thermoresponsive polymers PY - 2016 AN - OPUS4-37365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle A1 - Asadujjaman, Asad T1 - Phase transition and aggregation behavior of thermoresponsive copolymer Poly(acrylamide-co-acrylonitrile) N2 - The results of a study on the phase transition and aggregation behavior of the thermoresponsive copolymer Poly(acrylamide-co-acrylonitrile) are presented. T2 - Warwick Polymer Conference 2016 CY - Warwick, England DA - 11.07.2016 KW - Thermoresponsive polymers PY - 2016 AN - OPUS4-37366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle A1 - Asadujjaman, Asad A1 - Rurack, Knut T1 - Endowing nanoparticles with orthogonal functionalities via core / shell / shell architecture N2 - Dual orthogonal functionality in a single material is highly desirable in many fields such as bio-imaging, sensing, coating or diagnostic and therapy. However, combining two different functionalities in a precise and controlled way is still a challenging task. Here we present how simply dual functional hybrid nanoparticles consisting of a silica core with a fluorescent and a thermoresponsive polymeric layers can be prepared. As a first step of this work, silica core particles were coated by a fluorescent layer using surface-initiated reversible addition-fragmentation chain transfer polymerization. Afterwards, the fluorescent silica nanoparticles were completely enclosed in a switchable protective coating made of thermoresponsive poly(N-isopropylacrylamide). The thermoresponsive poly(N-isopropylacrylamide) changes its properties with varying the surroundings temperature and this behavior is reversible and controllable. To the best of our knowledge these types of hybrid dual functional core-shell-shell nanoparticles have not yet been prepared, despite the prospect of many potential applications. T2 - World Congress on Living Polymerizations and Polymers - LPP16 CY - Budapest, Hungary DA - 29.05.2016 KW - Fluorescent and thermoresponsive nanoparticles KW - Core KW - Shell KW - Shell nanoparticles PY - 2016 AN - OPUS4-37367 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 JF - Macromolecular Bioscience 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 - CONF A1 - Bertin, Annabelle A1 - Asadujjaman, Asad A1 - Rurack, Knut T1 - Endowing nanoparticles with orthogonal functionalities via core / shell / shell architecture N2 - Dual orthogonal functionality in a single material is highly desirable in many fields such as bio-imaging, sensing, coating or diagnostic and therapy. However, combining two different functionalities in a precise and controlled way is still a challenging task. Here we present how simply dual functional hybrid nanoparticles consisting of a silica core with a fluorescent and a thermoresponsive polymeric layers can be prepared. As a first step of this work, silica core particles were coated by a fluorescent layer using surface-initiated reversible addition-fragmentation chain transfer polymerization. Afterwards, the fluorescent silica nanoparticles were completely enclosed in a switchable protective coating made of thermoresponsive poly(N-isopropylacrylamide). The thermoresponsive poly(N-isopropylacrylamide) changes its properties with varying the surroundings temperature and this behavior is reversible and controllable. To the best of our knowledge these types of hybrid dual functional core-shell-shell nanoparticles have not yet been prepared, despite the prospect of many potential applications. T2 - 251st American Chemical Society National Meeting CY - San Diego, USA DA - 13.03.2016 KW - Fluorescent and thermoresponsive nanoparticles KW - Core / shell / shell / nanoparticles PY - 2016 AN - OPUS4-37370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle A1 - Taabache, Soraya A1 - Maskos, Michael T1 - Controlled self-assembly of dendritic amphiphiles in micromixers N2 - The controlled synthesis of supramolecular aggregates formed by the self-assembly of dendritic amphiphiles is a challenging task. Conventional batch-based techniques such as the solvent injection method or the film hydration method typically go along with a lack of control over mixing and thus over size, morphology and size distribution. The micromixer technology is a promising method for the controlled preparation of supramolecular assemblies as it allows control of mixing at microscale level. In addition, such microfluidic systems benefit from a high mixing efficiency, a low mixing time as well as from a reproducible and continuous synthesis. Herein, we report on the microfluidic-controlled self-assembly of several dendritic amphiphiles and the impact of the mixing parameters on the self-assembly process. T2 - 251st American Chemical Society National Meeting CY - San Diego, USA DA - 13.03.2016 KW - Dendritic amphiphiles KW - Self-assembly KW - Micromixer PY - 2016 AN - OPUS4-37371 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -