TY - JOUR A1 - Simsekyilmaz, Sakine A1 - Liehn, Elisa A. A1 - Weinandy, Stefan A1 - Schreiber, Fabian A1 - Megens, Remco T. A. A1 - Theelen, Wendy A1 - Smeets, Ralf A1 - Jockenhövel, Stefan A1 - Gries, Thomas A1 - Möller, Martin A1 - Klee, Doris A1 - Weber, Christian A1 - Zernecke, Alma T1 - Targeting In-Stent-Stenosis with RGD- and CXCL1-Coated Mini-Stents in Mice JF - PLoS ONE N2 - Atherosclerotic lesions that critically narrow the artery can necessitate an angioplasty and stent implantation. Long-term therapeutic effects, however, are limited by excessive arterial remodeling. We here employed a miniaturized nitinol-stent coated with star-shaped polyethylenglycole (star-PEG), and evaluated its bio-functionalization with RGD and CXCL1 for improving in-stent stenosis after implantation into carotid arteries of mice. Nitinol foils or stents (bare metal) were coated with star-PEG, and bio-functionalized with RGD, or RGD/CXCL1. Cell adhesion to star-PEG-coated nitinol foils was unaltered or reduced, whereas bio-functionalization with RGD but foremost RGD/CXCL1 increased adhesion of early angiogenic outgrowth cells (EOCs) and endothelial cells but not smooth muscle cells when compared with bare metal foils. Stimulation of cells with RGD/CXCL1 furthermore increased the proliferation of EOCs. In vivo, bio-functionalization with RGD/CXCL1 significantly reduced neointima formation and thrombus formation, and increased re-endothelialization in apoE\(^{-/-}\) carotid arteries compared with bare-metal nitinol stents, star-PEG-coated stents, and stents bio-functionalized with RGD only. Bio-functionalization of star-PEG-coated nitinol-stents with RGD/CXCL1 reduced in-stent neointima formation. By supporting the adhesion and proliferation of endothelial progenitor cells, RGD/CXCL1 coating of stents may help to accelerate endothelial repair after stent implantation, and thus may harbor the potential to limit the complication of in-stent restenosis in clinical approaches. KW - carotid arteries KW - polymers KW - stent implantation KW - coatings KW - endothelial cells KW - mice KW - fluorescence microscopy KW - stem cells Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-179745 VL - 11 IS - 5 ER - TY - JOUR A1 - Schroer, Guido A1 - Toussaint, Valérie A1 - Bachmann, Stephanie A1 - Pöppler, Ann‐Christin A1 - Gierlich, Christian Henning A1 - Delidovich, Irina T1 - Functional Phenylboronate Polymers for the Recovery of Diols, Sugar Alcohols, and Saccharides from Aqueous Solution JF - ChemSusChem N2 - The ongoing transition from fossil to renewable feedstocks demands new efficient processes for an economically viable production of biomass‐derived commodities and fine chemicals. Novel energy‐ and material‐efficient product purification and separation will play a crucial role due to altered product and feed composition. The present study comprises the synthesis and tests of cross‐linked p‐vinylphenylboronate polymers for the separation of 18 diols, sugar alcohols, and saccharides, which can be obtained during biomass processing. The separation was based on molecular recognition, that is, esterification of the phenylboronate with vicinal diols. A correlation of the molecular complexation constant, the polymer swelling, and the maximum adsorption capacity was found. The adsorption curves over time were recorded. Preliminary results on competitive adsorption of binary mixtures showed a high potential for the separation of substrates with significantly different complexation constants. Desorption tests implied easier desorption of substrates that only adsorb on the outer polymer shell. KW - adsorption KW - biomass KW - phenylboronate KW - polymers KW - separation techniques Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239889 VL - 14 IS - 23 SP - 5207 EP - 5215 ER - TY - JOUR A1 - Radakovic, D. A1 - Reboredo, J. A1 - Helm, M. A1 - Weigel, T. A1 - Schürlein, S. A1 - Kupczyk, E. A1 - Leyh, R. G. A1 - Walles, H. A1 - Hansmann, J. T1 - A multilayered electrospun graft as vascular access for hemodialysis JF - PLoS ONE N2 - Despite medical achievements, the number of patients with end-stage kidney disease keeps steadily raising, thereby entailing a high number of surgical and interventional procedures to establish and maintain arteriovenous vascular access for hemodialysis. Due to vascular disease, aneurysms or infection, the preferred access—an autogenous arteriovenous fistula—is not always available and appropriate. Moreover, when replacing small diameter blood vessels, synthetic vascular grafts possess well-known disadvantages. A continuous multilayered gradient electrospinning was used to produce vascular grafts made of collagen type I nanofibers on luminal and adventitial graft side, and poly-ɛ-caprolactone as medial layer. Therefore, a custom-made electrospinner with robust environmental control was developed. The morphology of electrospun grafts was characterized by scanning electron microscopy and measurement of mechanical properties. Human microvascular endothelial cells were cultured in the graft under static culture conditions and compared to cultures obtained from dynamic continuous flow bioreactors. Immunofluorescent analysis showed that endothelial cells form a continuous luminal layer and functional characteristics were confirmed by uptake of acetylated low-density-lipoprotein. Incorporation of vancomycin and gentamicin to the medial graft layer allowed antimicrobial inhibition without exhibiting an adverse impact on cell viability. Most striking a physiological hemocompatibility was achieved for the multilayered grafts. KW - collagens KW - polymers KW - vascular surgery KW - endothelial cells KW - cell cultures KW - blood KW - antibiotics KW - scanning electron microscopy Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159102 VL - 12 IS - 10 ER - TY - JOUR A1 - Pöppler, Ann-Christin A1 - Lübtow, Michael M. A1 - Schlauersbach, Jonas A1 - Wiest, Johannes A1 - Meinel, Lorenz A1 - Luxenhofer, Robert T1 - Loading dependent Structural Model of Polymeric Micelles Encapsulating Curcumin by Solid-State NMR Spectroscopy JF - Angewandte Chemie International Edition N2 - Detailed insight into the internal structure of drug‐loaded polymeric micelles is scarce, but important for developing optimized delivery systems. We observed that an increase in the curcumin loading of triblock copolymers based on poly(2‐oxazolines) and poly(2‐oxazines) results in poorer dissolution properties. Using solid‐state NMR spectroscopy and complementary tools we propose a loading‐dependent structural model on the molecular level that provides an explanation for these pronounced differences. Changes in the chemical shifts and cross‐peaks in 2D NMR experiments give evidence for the involvement of the hydrophobic polymer block in the curcumin coordination at low loadings, while at higher loadings an increase in the interaction with the hydrophilic polymer blocks is observed. The involvement of the hydrophilic compartment may be critical for ultrahigh‐loaded polymer micelles and can help to rationalize specific polymer modifications to improve the performance of similar drug delivery systems. KW - dissolution rates KW - micelles KW - polymers KW - short-range order KW - solid-state NMR spectroscopy Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-206705 VL - 58 IS - 51 ER - TY - JOUR A1 - Lamberger, Zan A1 - Zainuddin, Shakir A1 - Scheibel, Thomas A1 - Lang, Gregor T1 - Polymeric Janus Fibers JF - ChemPlusChem N2 - Janus fibers are a class of composite materials comprising mechanical and chemical to biological functionality. Combining different materials and functionalities in one micro- or even nanoscale fiber enables otherwise unreachable synergistic physicochemical effects with unprecedented opportunities for technical or biomedical applications. Here, recent developments of processing technologies and applications of polymeric Janus fibers will be reviewed. Various examples in the fields of textiles, catalysis, sensors as well as medical applications, like drug delivery systems, tissue engineering and antimicrobial materials, are presented to illuminate the outstanding potential of such high-end functional materials for novel applications in the upcoming future. KW - hybrid materials KW - polymers KW - nanofibers KW - spinning KW - Janus fibers Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318516 VL - 88 IS - 2 ER - TY - JOUR A1 - Fetsch, Corinna A1 - Gaitzsch, Jens A1 - Messager, Lea A1 - Battaglia, Giuseppe A1 - Luxenhofer, Roberts T1 - Self-Assembly of Amphiphilic Block Copolypeptoids – Micelles, Worms and Polymersomes JF - Scientific Reports N2 - Polypeptoids are an old but recently rediscovered polymer class with interesting synthetic, physico-chemical and biological characteristics. Here, we introduce new aromatic monomers, N-benzyl glycine N-carboxyanhydride and N-phenethyl glycine N-carboxyanhydride and their block copolymers with the hydrophilic polysarcosine. We compare their self-assembly in water and aqueous buffer with the self-assembly of amphiphilic block copolypeptoids with aliphatic side chains. The aggregates in water were investigated by dynamic light scattering and electron microscopy. We found a variety of morphologies, which were influenced by the polymer structure as well as by the preparation method. Overall, we found polymersomes, worm-like micelles and oligo-lamellar morphologies as well as some less defined aggregates of interconnected worms and vesicles. Such, this contribution may serve as a starting point for a more detailed investigation of the self-assembly behavior of the rich class of polypeptoids and for a better understanding between the differences in the aggregation behavior of non-uniform polypeptoids and uniform peptoids. KW - bioinspired materials KW - polymer characterization KW - polymer synthesis KW - polymers KW - self-assembly Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147855 VL - 6 ER - TY - JOUR A1 - Esmaeilpour, Donya A1 - Broscheit, Jens Albert A1 - Shityakov, Sergey T1 - Cyclodextrin-based polymeric materials bound to corona protein for theranostic applications JF - International Journal of Molecular Sciences N2 - Cyclodextrins (CDs) are cyclic oligosaccharide structures that could be used for theranostic applications in personalized medicine. These compounds have been widely utilized not only for enhancing drug solubility, stability, and bioavailability but also for controlled and targeted delivery of small molecules. These compounds can be complexed with various biomolecules, such as peptides or proteins, via host-guest interactions. CDs are amphiphilic compounds with water-hating holes and water-absorbing surfaces. Architectures of CDs allow the drawing and preparation of CD-based polymers (CDbPs) with optimal pharmacokinetic and pharmacodynamic properties. These polymers can be cloaked with protein corona consisting of adsorbed plasma or extracellular proteins to improve nanoparticle biodistribution and half-life. Besides, CDs have become famous in applications ranging from biomedicine to environmental sciences. In this review, we emphasize ongoing research in biomedical fields using CD-based centered, pendant, and terminated polymers and their interactions with protein corona for theranostic applications. Overall, a perusal of information concerning this novel approach in biomedicine will help to implement this methodology based on host-guest interaction to improve therapeutic and diagnostic strategies. KW - cyclodextrin KW - theranostics KW - protein corona KW - nanomedicine KW - therapy KW - polymers Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297399 SN - 1422-0067 VL - 23 IS - 21 ER - TY - JOUR A1 - Brüning, Christoph A1 - Wehner, Johannes A1 - Hausner, Julian A1 - Wenzel, Michael A1 - Engel, Volker T1 - Exciton dynamics in perturbed vibronic molecular aggregates JF - Structural Dynamics N2 - A site specific perturbation of a photo-excited molecular aggregate can lead to a localization of excitonic energy. We investigate this localization dynamics for laser-prepared excited states. Changing the parameters of the electric field significantly influences the exciton localization which offers the possibility for a selective control of this process. This is demonstrated for aggregates possessing a single vibrational degree of freedom per monomer unit. It is shown that the effects identified for the molecular dimer can be generalized to larger aggregates with a high density of vibronic states. KW - absorption spectra KW - excited states KW - polymers KW - excitons KW - wave functions Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126085 VL - 3 ER - TY - JOUR A1 - Brosge, Felix A1 - Lorenz, Thomas A1 - Helten, Holger A1 - Bolm, Carsten T1 - BN- and BO-Doped Inorganic–Organic Hybrid Polymers with Sulfoximine Core Units JF - Chemistry - A European Journal N2 - While polysulfones constitute a class of well‐established, highly valuable applied materials, knowledge about polymers based on the related sulfoximine group is very limited. We have employed functionalized diaryl sulfoximines and a p ‐phenylene bisborane as building blocks for unprecedented BN‐ and BO‐doped alternating inorganic–organic hybrid copolymers. While the former were accessed by a facile silicon/boron exchange protocol, the synthesis of polymers with main‐chain B–O linkages was achieved by salt elimination. KW - boron KW - hybrid materials KW - polymers KW - sulfoimines KW - sulfur Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-206194 VL - 25 IS - 55 ER - TY - JOUR A1 - Arca, Francesco A1 - Tedde, Sandro F. A1 - Sramek, Maria A1 - Rauh, Julia A1 - Lugli, Paolo A1 - Hayden, Oliver T1 - Interface Trap States in Organic Photodiodes JF - Scientific Reports N2 - Organic semiconductors are attractive for optical sensing applications due to the effortless processing on large active area of several \(cm^2\), which is difficult to achieve with solid-state devices. However, compared to silicon photodiodes, sensitivity and dynamic behavior remain a major challenge with organic sensors. Here, we show that charge trapping phenomena deteriorate the bandwidth of organic photodiodes (OPDs) to a few Hz at low-light levels. We demonstrate that, despite the large OPD capacitances of similar to 10 nF \(cm^{-2}\), a frequency response in the kHz regime can be achieved at light levels as low as 20 nW \(cm^{-2}\) by appropriate interface engineering, which corresponds to a 1000-fold increase compared to state-of-the-art OPDs. Such device characteristics indicate that large active area OPDs are suitable for industrial sensing and even match medical requirements for single X-ray pulse detection in the millisecond range. KW - ultrafast photonics KW - materials for optics KW - electrical and electronic engineering KW - polymers Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131507 VL - 3 ER -