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2. PEtOxylated polyesteramide nanoparticles for the delivery of anti-inflammatory drugs

Author

Behnke, Mira, Vollrath, Antje, Dahlke, Philipp, Larios, Francisco Páez, Chi, Mingzhe, Tsarenko, Ekaterina, Jordan, Paul M., Weber, Christine, Dirauf, Michael, Czaplewska, Justyna Anna, Beringer-Siemers, Baerbel, Stumpf, Steffi, Kellner, Carolin, Kretzer, Christian, Hoeppener, Stephanie, Nischang, Ivo, Sierka, Marek, Eggeling, Christian, Werz, Oliver, and Schubert, Ulrich S.

Published
2024
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8. Automated screening of precipitation polymerizations and evaluation using image recognition for divinylbenzene and methacrylic acid.

Author

Schuett, Timo, Endres, Patrick, Kimmig, Julian, Lorenz, Robert, Köster, Yannik, Stumpf, Steffi, Zechel, Stefan, and Schubert, Ulrich S.

Subjects
METHACRYLIC acid, IMAGE recognition (Computer vision), EMULSION polymerization, NUCLEAR magnetic resonance, PARTICLE size distribution
Abstract

By applying automated high‐throughput experimentation, 63 precipitation polymerizations of divinylbenzene and methacrylic acid were performed with a total of 1638 samples analyzed by gas chromatography (GC), nuclear magnetic resonance (NMR) spectroscopy, and scanning electron microscopy (SEM). The conversion of each reaction was investigated revealing the best substrate concentrations within the current setup. The GC evaluation was performed automatically via a new custom‐made Python script significantly reducing the time to evaluate the results. Furthermore, the particle growth was monitored by utilizing an innovative image recognition tool to identify particles and their respective sizes using SEM images. Furthermore, a statistical particle size distribution analysis was performed, which is hardly achievable in reasonable time by classical evaluation methods. Using this new procedure, the highest conversion (70%) as well as the largest particles (3700 nm) have been obtained utilizing a high initial monomer (5 vol%) and initiator (5 mol%) concentration. Accordingly, the smallest particles (245 nm) yielded from the lowest starting concentration (1 vol% monomer and 1 mol% initiator). [ABSTRACT FROM AUTHOR]

Published
2024
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9. Dual‐Use Self‐Assembled Monolayer Controlling Charge Carrier Extraction in Organic Solar Cells.

Author

Xu, Zhuo, Meitzner, Rico, Anand, Aman, Djoumessi, Aurelien Sokeng, Stumpf, Steffi, Neumann, Christof, Turchanin, Andrey, Müller, Frank A., Schubert, Ulrich S., and Hoppe, Harald

Subjects
SOLAR cells, CHARGE carriers, PRICES, MONOMOLECULAR films
Abstract

The development and use of interface materials are essential to the continued advancement of organic solar cells (OSCs) performance. Self‐assembled monolayer (SAM) materials have drawn attention because of their simple structure and affordable price. Due to their unique properties, they may be used in inverted devices as a modification layer for modifying ZnO or as a hole transport layer (HTL) in place of typical poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) in conventional devices. In this work, zinc oxide (ZnO) is modified using five structurally similar SAM materials. This resulted in a smoother surface, a decrease in work function, a suppression of charge recombination, and an increase in device efficiency and photostability. In addition, they can introduced asfor hole extraction layer between the active layer and MoO3, enabling the use of the same material at several functional layers in the same device. Through systematic orthogonal evaluation, it is shown that some SAM/active layer/SAM combinations still offered device efficiencies comparable to ZnO/SAM, but with improved device' photostability. This study may provide recommendations for future SAM material's design and development as well as a strategy for boosting device performance by using the same material across both sides of the photoactive layer in OSCs. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Ethoxy acetalated dextran-based nanocarriers accomplish efficient inhibition of leukotriene formation by a novel FLAP antagonist in human leukocytes and blood

Author

Kretzer, Christian, Shkodra, Blerina, Klemm, Paul, Jordan, Paul M., Schröder, Daniel, Cinar, Gizem, Vollrath, Antje, Schubert, Stephanie, Nischang, Ivo, Hoeppener, Stephanie, Stumpf, Steffi, Banoglu, Erden, Gladigau, Frederike, Bilancia, Rossella, Rossi, Antonietta, Eggeling, Christian, Neugebauer, Ute, Schubert, Ulrich S., and Werz, Oliver

Published
2022
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12. Evaluation of in situ thermal stability assessment for flow batteries and deeper investigation of the ferrocene co-polymer

Author

Schubert, Ulrich S., primary, Volodin, Ivan, additional, Wulf, Katrin, additional, Tzschoeckell, Felix, additional, Stumpf, Steffi, additional, Hoeppener, Stephanie, additional, Fritz, Nicole, additional, Morales-Reyes, Cristina, additional, Wichard, Thomas, additional, Ueberschaar, Nico, additional, Stolze, Christian, additional, and Hager, Martin D., additional

Published
2024
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13. Electronic and Photochemical Passivation by a Classic Sunscreen Material Leading to Reduced Voc Losses and Enhanced Stability in Organic Solar Cells

Author

Xu, Zhuo, primary, Islam, Md Moidul, additional, Meitzner, Rico, additional, Anand, Aman, additional, Djoumessi, Aurelien Sokeng, additional, Stumpf, Steffi, additional, Hoeppener, Stephanie, additional, Neumann, Christof, additional, Turchanin, Andrey, additional, Schubert, Ulrich S., additional, and Hoppe, Harald, additional

Published
2023
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15. Evaluation of in situ thermal stability assessment for flow batteries and deeper investigation of the ferrocene co-polymer.

Author

Volodin, Ivan A., Wulf, Katrin, Tzschoeckell, Felix, Stumpf, Steffi, Hoeppener, Stephanie, Fritz, Nicole, Morales-Reyes, Cristina F., Wichard, Thomas, Ueberschaar, Nico, Stolze, Christian, Hager, Martin D., and Schubert, Ulrich S.

Abstract

The stability of reported organic materials for redox flow batteries (RFB) continues to improve. Consequently, the relevance of analytical techniques to assess degradation rates also grows. To contribute to the development of in operando thermal stability assessment techniques, we evaluated the commonly-reported heating setups using the ferrocene-based FPMAm-co-METAC polymer (PFc) in a Zn-based hybrid RFB with a size-exclusion membrane. In the first stage, the conditions for RFB cycling were selected and evaluated. The amperometric SOC measurement technique revealed oxygen intolerance of the PFc. While no polymer cross-over was detected, cross-over of its hydrolysis products occurred and facilitated the capacity fade. Adjustment of membrane pore size and electrolyte composition helped to mitigate the hydrolyzed products' cross-over. In the second stage, different heating setups for the thermal stability evaluation of PFc were compared. Eventually, a thermostatic setup established the desired temperature most accurately and homogeneously, while the popular oil/sand bath setup exhibited a deviation of 22 °C down from the expected 60 °C. The PFc stability was further evaluated from ambient conditions (28 °C) to 60 °C. At temperatures above 50 °C a facilitated capacity fade was observed. The volumetrically unbalanced, compositionally symmetric flow cell cycling has unraveled that the degradation was caused by catholyte self-reduction and following half-cell imbalances. A mechanism involving the ferrocene complex decomposition is proposed as the origin of the catholyte self-reduction. Finally, the properties and thermal stability of the PFc material as well as the reliability of the studied heating setups are discussed. [ABSTRACT FROM AUTHOR]

Published
2024
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16. PEG–Lipid–PLGA Hybrid Particles for Targeted Delivery of Anti-Inflammatory Drugs.

Author

Ismail, Jana, Klepsch, Lea C., Dahlke, Philipp, Tsarenko, Ekaterina, Vollrath, Antje, Pretzel, David, Jordan, Paul M., Rezaei, Kourosh, Czaplewska, Justyna A., Stumpf, Steffi, Beringer-Siemers, Baerbel, Nischang, Ivo, Hoeppener, Stephanie, Werz, Oliver, and Schubert, Ulrich S.

Subjects
TARGETED drug delivery, DRUG delivery systems, HIGH performance liquid chromatography, ANTI-inflammatory agents, SCANNING electron microscopy
Abstract

Hybrid nanoparticles (HNPs) were designed by combining a PLGA core with a lipid shell that incorporated PEG–Lipid conjugates with various functionalities (-RGD, -cRGD, -NH2, and -COOH) to create targeted drug delivery systems. Loaded with a neutral lipid orange dye, the HNPs were extensively characterized using various techniques and investigated for their uptake in human monocyte-derived macrophages (MDMs) using FC and CLSM. Moreover, the best-performing HNPs (i.e., HNP-COOH and HNP-RGD as well as HNP-RGD/COOH mixed) were loaded with the anti-inflammatory drug BRP-201 and prepared in two size ranges (dH ~140 nm and dH ~250 nm). The HNPs were examined further for their stability, degradation, MDM uptake, and drug delivery efficiency by studying the inhibition of 5-lipoxygenase (5-LOX) product formation, whereby HNP-COOH and HNP-RGD both exhibited superior uptake, and the HNP-COOH/RGD (2:1) displayed the highest inhibition. [ABSTRACT FROM AUTHOR]

Published
2024
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19. A user-guide for polymer purification using dialysis

Author

Schuett, Timo, primary, Anufriev, Ilya, additional, Endres, Patrick, additional, Stumpf, Steffi, additional, Nischang, Ivo, additional, Hoeppener, Stephanie, additional, Zechel, Stefan, additional, Schubert, Ulrich S., additional, and Geitner, Robert, additional

Published
2023
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27. Coordination of Noble Metals in Poly(vinyl mercaptoethanol) Particles Prepared by Precipitation/Emulsion Polymerization.

Author

Ziegenbalg, Nicole, Ulrich, Hans F., Stumpf, Steffi, Mueller, Philipp, Wiethan, Jürgen, Danner, Janette, Schubert, Ulrich S., Adermann, Torben, and Brendel, Johannes C.

Subjects
PRECIOUS metals, POLYMERS, METALLIC composites, MERCAPTOETHANOL, METALWORK, EMULSION polymerization, POLYMERIZATION
Abstract

S‐Vinyl monomers react readily in radical polymerizations resulting in polymers with interesting features such as enhanced refractive indices, increased thermal stability, or the ability to coordinate various metals. Among them, vinyl mercaptoethanol (VME) can be produced in industrial scale, but the poor solubility of the resulting homopolymer limits its application. In this contribution, polymerizations of the monomer are investigated in water forming a heterogeneous system. The good solubility of the monomer in water imparts the system with mixed characteristics between a precipitation and an emulsion polymerization. Evaluating various surfactants, only polyvinyl alcohol (PVA) is found to create stable dispersions, although micrometer‐sized particles are formed with a broad size distribution. Nevertheless, the particles are able to coordinate silver or gold ions. Attempts to reduce the noble metal ions by commercial reducing agents fail. However, exposure to sunlight unexpectedly results in a controlled reduction of the metal ions and the formation of composite particles. Silver ion‐containing dispersions demonstrate strong antibacterial properties, while the effect is diminished in the corresponding composite. Overall, the precipitation/emulsion polymerization of VME represents a promising pathway to stable sulfur‐rich polymer dispersions with the ability to coordinate metal ions or form reactive metal composites. [ABSTRACT FROM AUTHOR]

Published
2023
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29. Ethoxy acetalated dextran-based nanocarriers accomplish efficient inhibition of leukotriene formation by a novel FLAP antagonist in human leukocytes and blood

Author

Kretzer, Christian, primary, Shkodra, Blerina, additional, Klemm, Paul, additional, Jordan, Paul M., additional, Schröder, Daniel, additional, Cinar, Gizem, additional, Vollrath, Antje, additional, Schubert, Stephanie, additional, Nischang, Ivo, additional, Hoeppener, Stephanie, additional, Stumpf, Steffi, additional, Banoglu, Erden, additional, Gladigau, Frederike, additional, Bilancia, Rossella, additional, Rossi, Antonietta, additional, Eggeling, Christian, additional, Neugebauer, Ute, additional, Schubert, Ulrich S., additional, and Werz, Oliver, additional

Published
2021
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30. Effect of Crystallinity on the Properties of Polycaprolactone Nanoparticles Containing the Dual FLAP/mPEGS-1 Inhibitor BRP-187

Author

Vollrath, Antje, Kretzer, Christian, Beringer-Siemers, Bärbel, Shkodra, Blerina, Czaplewska, Justyna A., Bandelli, Damiano, Stumpf, Steffi, Hoeppener, Stephanie, Weber, Christine, Werz, Oliver, and Schubert, Ulrich S.

Subjects
hydrophobic-hydrophilic balance (HHB), QD241-441, polycaprolactone (PCL), nanoparticle crystallinity, Organic chemistry, FLAP antagonist, nanoparticle formulation, polyesters, BRP-187, Article
Abstract

Seven polycaprolactones (PCL) with constant hydrophobicity but a varying degree of crystallinity prepared from the constitutional isomers ε-caprolactone (εCL) and δ-caprolactone (δCL) were utilized to formulate nanoparticles (NPs). The aim was to investigate the effect of the crystallinity of the bulk polymers on the enzymatic degradation of the particles. Furthermore, their efficiency to encapsulate the hydrophobic anti-inflammatory drug BRP-187 and the final in vitro performance of the resulting NPs were evaluated. Initially, high-throughput nanoprecipitation was employed for the εCL and δCL homopolymers to screen and establish important formulation parameters (organic solvent, polymer and surfactant concentration). Next, BRP-187-loaded PCL nanoparticles were prepared by batch nanoprecipitation and characterized using dynamic light scattering, scanning electron microscopy and UV-Vis spectroscopy to determine and to compare particle size, polydispersity, zeta potential, drug loading as well as the apparent enzymatic degradation as a function of the copolymer composition. Ultimately, NPs were examined for their potency in vitro in human polymorphonuclear leukocytes to inhibit the BRP-187 target 5-lipoxygenase-activating protein (FLAP). It was evident by Tukey’s multi-comparison test that the degree of crystallinity of copolymers directly influenced their apparent enzymatic degradation and consequently their efficiency to inhibit the drug target.

Published
2021

36. Encapsulation of the dual FLAP/mPEGS-1 inhibitor BRP-187 into acetalated dextran and PLGA nanoparticles improves its cellular bioactivity

Author

Shkodra-Pula, Blerina, primary, Kretzer, Christian, additional, Jordan, Paul M., additional, Klemm, Paul, additional, Koeberle, Andreas, additional, Pretzel, David, additional, Banoglu, Erden, additional, Lorkowski, Stefan, additional, Wallert, Maria, additional, Höppener, Stephanie, additional, Stumpf, Steffi, additional, Vollrath, Antje, additional, Schubert, Stephanie, additional, Werz, Oliver, additional, and Schubert, Ulrich, additional

Published
2020
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