TY - JOUR A1 - Tang, Jo Sing Julia A1 - Smaczniak, Aline Debrassi A1 - Tepper, Lucas A1 - Rosencrantz, Sophia A1 - Aleksanyan, Mina A1 - Dähne, Lars A1 - Rosencrantz, Ruben R. T1 - Glycopolymer based LbL multilayer thin films with embedded liposomes JF - Macromolecular bioscience N2 - Layer-by-layer (LbL) self-assembly emerged as an efficient technique for fabricating coating systems for, e.g., drug delivery systems with great versatility and control. In this work, protecting group free and aqueous-based syntheses of bioinspired glycopolymer electrolytes aredescribed. Thin films of the glycopolymers are fabricated by LbL self-assembly and function as scaffolds for liposomes, which potentially can encapsulate active substances. The adsorbed mass, pH stability, and integrity of glycopolymer coatings as well as the embedded liposomes are investigated via whispering gallery mode (WGM) technology and quartz crystal microbalance with dissipation (QCM-D) monitoring , which enable label-free characterization. Glycopolymer thin films, with and without liposomes, are stable in the physiological pH range. QCM-D measurements verify the integrity of lipid vesicles. Thus, the fabrication of glycopolymer-based surface coatings with embedded and intact liposomes is presented. KW - glycopolymers KW - layer-by-layer self-assembly KW - liposomes KW - polyelectrolyte KW - multilayer film Y1 - 2022 U6 - https://doi.org/10.1002/mabi.202100461 SN - 1616-5187 SN - 1616-5195 VL - 22 IS - 4 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Chea, Sany A1 - Nguyen, Khac Toan A1 - Rosencrantz, Ruben R. T1 - Microwave-Assisted Synthesis of 5 '-O-methacryloylcytidine Using the Immobilized Lipase Novozym 435 JF - Molecules N2 - Nucleobase building blocks have been demonstrated to be strong candidates when it comes to DNA/RNA-like materials by benefiting from hydrogen bond interactions as physical properties. Modifying at the 5 ' position is the simplest way to develop nucleobase-based structures by transesterification using the lipase Novozym 435. Herein, we describe the optimization of the lipase-catalyzed synthesis of the monomer 5 '-O-methacryloylcytidine with the assistance of microwave irradiation. Variable reaction parameters, such as enzyme concentration, molar ratio of the substrate, reaction temperature and reaction time, were investigated to find the optimum reaction condition in terms of obtaining the highest yield. KW - microwave irradiation KW - Novozym 435 KW - cytidine KW - monomer KW - smart materials Y1 - 2022 U6 - https://doi.org/10.3390/molecules27134112 SN - 1420-3049 VL - 27 IS - 13 PB - MDPI CY - Basel ER - TY - JOUR A1 - Chea, Sany A1 - Schade, Kristin A1 - Reinicke, Stefan A1 - Bleul, Regina A1 - Rosencrantz, Ruben R. T1 - Synthesis and self-assembly of cytidine- and guanosine-based copolymers JF - Polymer Chemistry N2 - The base pairing property and the "melting" behavior of oligonucleotides can take advantage to develop new smart thermoresponsive and programmable materials. Complementary cytidine- (C) and guanosine- (G) based monomers were blockcopolymerized using RAFT polymerization technique with poly-(N-(2-hydroxypropyl) methacrylamide) (pHPMA) as the hydrophilic macro chain transfer agent (macro-CTA). C-C, G-G and C-G hydrogen bond interactions of blockcopolymers with respectively C and G moieties have been investigated using SEM, DLS and UV-Vis. Mixing and heating both complementary copolymers resulted in reforming new aggregates. Due to the ribose moiety of the isolated nucleoside-bearing blockcopolymers, the polarity is increased for better solubility. Self-assembly investigations of these bioinspired compounds are the crucial basis for the development of potential future drug delivery systems. Y1 - 2022 U6 - https://doi.org/10.1039/d2py00615d SN - 1759-9954 SN - 1759-9962 VL - 13 IS - 35 SP - 5058 EP - 5067 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Doering, Ulrike A1 - Grigoriev, Dmitry A1 - Tapio, Kosti A1 - Rosencrantz, Sophia A1 - Rosencrantz, Ruben R. A1 - Bald, Ilko A1 - Böker, Alexander T1 - About the mechanism of ultrasonically induced protein capsule formation JF - RSC Advances : an international journal to further the chemical sciences / Royal Society of Chemistry N2 - In this paper, we propose a consistent mechanism of protein microcapsule formation upon ultrasound treatment. Aqueous suspensions of bovine serum albumin (BSA) microcapsules filled with toluene are prepared by use of high-intensity ultrasound following a reported method. Stabilization of the oil-in-water emulsion by the adsorption of the protein molecules at the interface of the emulsion droplets is accompanied by the creation of the cross-linked capsule shell due to formation of intermolecular disulfide bonds caused by highly reactive species like superoxide radicals generated sonochemically. The evidence for this mechanism, which until now remained elusive and was not proven properly, is presented based on experimental data from SDS-PAGE, Raman spectroscopy and dynamic light scattering. Y1 - 2021 U6 - https://doi.org/10.1039/d0ra08100k SN - 2046-2069 VL - 11 IS - 27 SP - 16152 EP - 16157 PB - RSC Publishing CY - London ER - TY - JOUR A1 - Pacholski, Claudia A1 - Rosencrantz, Sophia A1 - Rosencrantz, Ruben R. A1 - Balderas-Valadez, Ruth Fabiola T1 - Plasmonic biosensors fabricated by galvanic displacement reactions for monitoring biomolecular interactions in real time JF - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica N2 - Optical sensors are prepared by reduction of gold ions using freshly etched hydride-terminated porous silicon, and their ability to specifically detect binding between protein A/rabbit IgG and asialofetuin/Erythrina cristagalli lectin is studied. The fabrication process is simple, fast, and reproducible, and does not require complicated lab equipment. The resulting nanostructured gold layer on silicon shows an optical response in the visible range based on the excitation of localized surface plasmon resonance. Variations in the refractive index of the surrounding medium result in a color change of the sensor which can be observed by the naked eye. By monitoring the spectral position of the localized surface plasmon resonance using reflectance spectroscopy, a bulk sensitivity of 296 nm +/- 3 nm/RIU is determined. Furthermore, selectivity to target analytes is conferred to the sensor through functionalization of its surface with appropriate capture probes. For this purpose, biomolecules are deposited either by physical adsorption or by covalent coupling. Both strategies are successfully tested, i.e., the optical response of the sensor is dependent on the concentration of respective target analyte in the solution facilitating the determination of equilibrium dissociation constants for protein A/rabbit IgG as well as asialofetuin/Erythrina cristagalli lectin which are in accordance with reported values in literature. These results demonstrate the potential of the developed optical sensor for cost-efficient biosensor applications. KW - Optical sensor KW - Gold nanostructure KW - Localized surface plasmon resonance KW - Surface functionalization KW - Biomolecular interactions KW - Lectin Y1 - 2020 U6 - https://doi.org/10.1007/s00216-020-02414-0 SN - 1618-2642 SN - 1618-2650 VL - 412 IS - 14 SP - 3433 EP - 3445 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Reinicke, Stefan A1 - Rees, Huw C. A1 - Espeel, Pieter A1 - Vanparijs, Nane A1 - Bisterfeld, Carolin A1 - Dick, Markus A1 - Rosencrantz, Ruben R. A1 - Brezesinski, Gerald A1 - de Geest, Bruno G. A1 - Du Prez, Filip E. A1 - Pietruszka, Jörg A1 - Böker, Alexander T1 - Immobilization of 2-Deoxy-D-ribose-5-phosphate Aldolase in Polymeric Thin Films via the Langmuir-Schaefer Technique JF - ACS applied materials & interfaces N2 - A synthetic protocol for the fabrication of ultrathin polymeric films containing the enzyme 2-deoxy-D-ribose-5-phosphate aldolase from Escherichia coli (DERA(EC)) is presented. Ultrathin enzymatically active films are useful for applications in which only small quantities of active material are needed and at the same time quick response and contact times without diffusion limitation are wanted. We show how DERA as an exemplary enzyme can be immobilized in a thin polymer layer at the air-water interface and transferred to a suitable support by the Langmuir-Schaefer technique under full conservation of enzymatic activity. The polymer in use is a poly(N-isopropylacrylamide-co-N-2-thiolactone acrylamide) (P(NIPAAm-co-TlaAm)) statistical copolymer in which the thiolactone units serve a multitude of purposes including hydrophobization of the polymer, covalent binding of the enzyme and the support and finally cross-linking of the polymer matrix. The application of this type of polymer keeps the whole approach simple as additional cocomponents such as cross-linkers are avoided. KW - Langmuir-Schaefer KW - enzyme immobilization KW - 2-deoxy-D-ribose-5-phosphate aldolase KW - polymeric thin film KW - poly(N-isopropylacrylamide) KW - thiolactone Y1 - 2017 U6 - https://doi.org/10.1021/acsami.6b13632 SN - 1944-8244 VL - 9 SP - 8317 EP - 8326 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Rosencrantz, Sophia A1 - Tang, Jo Sing Julia A1 - Schulte-Osseili, Christine A1 - Böker, Alexander A1 - Rosencrantz, Ruben R. T1 - Glycopolymers by RAFT Polymerization as Functional Surfaces for Galectin-3 JF - Macromolecular chemistry and physics N2 - Glycan-protein interactions are essential biological processes with many disease-related modulations and variations. One of the key proteins involved in tumor progression and metastasis is galectin-3 (Gal-3). A lot of effort is put into the development of Gal-3 inhibitors as new therapeutic agents. The avidity of glycan-protein interactions is strongly enhanced by multivalent ligand presentation. Multivalent presentation of glycans can be accomplished by utilizing glycopolymers, which are polymers with pendent glycan groups. For the production of glycopolymers, glycomonomers are synthesized by a regioselective, microwave-assisted approach starting from lactose. The resulting methacrylamide derivatives are polymerized by RAFT and immobilized on gold surfaces using the trithiocarbonate group of the chain transfer agent. Surface plasmon resonance spectroscopy enables the label free kinetic characterization of Gal-3 binding to these multivalent glycopolymers. The measurements indicate oligomerization of Gal-3 upon exposure to multivalent environments and reveal strong specific interaction with the immobilized polymers. KW - galectin-3 KW - glycopolymers KW - multivalency KW - RAFT KW - surface plasmon resonance Y1 - 2019 U6 - https://doi.org/10.1002/macp.201900293 SN - 1022-1352 SN - 1521-3935 VL - 220 IS - 20 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Park, H. A1 - Walta, S. A1 - Rosencrantz, Ruben R. A1 - Koerner, A. A1 - Schulte, Christoph A1 - Elling, L. A1 - Richtering, Walter A1 - Böker, Alexander T1 - Micelles from self-assembled double-hydrophilic PHEMA-glycopolymer-diblock copolymers as multivalent scaffolds for lectin binding JF - Polymer Chemistry N2 - We introduce a novel double-hydrophilic hydroxyethylmethacrylate (HEMA) based diblock glycopolymer which self-assembles into homogeneous spherical micellar structures in water. The micellar structure renders surface-oriented N-acetylglucocosamine (GlcNAc) sugar moieties for strong multivalent glycan-mediated lectin binding. Structural analysis and lectin binding is performed by microscopy methods, dynamic light scattering (DLS) and two-focus fluorescence correlation spectroscopy (2fFCS), revealing a novel micellar type of multivalent sugar binding scaffold with high potential for biomedical applications. Y1 - 2016 U6 - https://doi.org/10.1039/c5py00797f SN - 1759-9954 SN - 1759-9962 VL - 7 SP - 878 EP - 886 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Rosencrantz, Ruben R. A1 - Vu Hoa Nguyen, A1 - Park, Hyunji A1 - Schulte, Christine A1 - Böker, Alexander A1 - Schnakenberg, Uwe A1 - Elling, Lothar T1 - Lectin binding studies on a glycopolymer brush flow-through biosensor by localized surface plasmon resonance JF - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry and Analusis N2 - A localized surface plasmon resonance biosensor in a flow-through configuration was applied for investigating kinetics of lectin binding to surface-grafted glycopolymer brushes. Polycarbonate filter membranes with pore sizes of 400 nm were coated with a 114-nm thick gold layer and used as substrate for surface-initiated atom-transfer radical polymerization of a glycomonomer. These grafted from glycopolymer brushes were further modified with two subsequent enzymatic reactions on the surface to yield an immobilized trisaccharide presenting brush. Specific binding of lectins including Clostridium difficile toxin A receptor domain to the glycopolymer brush surface could be investigated in a microfluidic setup with flow-through of the analytes and transmission surface plasmon resonance spectroscopy. KW - Localized surface plasmon resonance KW - Glycopolymer brush KW - Microfluidics KW - Bacterial toxin KW - Glycosyltransferase KW - Biosensors Y1 - 2016 U6 - https://doi.org/10.1007/s00216-016-9667-9 SN - 1618-2642 SN - 1618-2650 VL - 408 SP - 5633 EP - 5640 PB - Springer CY - Heidelberg ER -