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General
- Hydrodynamic and light scattering studies of macromolecules and colloidal systems
- Characterization of polymer structures and colloids in solution
- Separation science (centrifugation−based techniques, chromatography, field−flow fractionation)
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Hydrodynamics of Macromolecules & Colloids
We utilize the interrelation of rotational and translational friction data to verify information obtained from a variety of (molecular) hydrodynamic techniques. The obtained set of data is utilized to descibe polymers and colloidal objects in solution most comprehensively.
Our experiments assessing molecular properties include:
- (Intrinsic) viscosity
- (Intrinsic) sedimentation coefficients
- (Intrinsic) diffusion coefficients
- (Molecular) densimetry, partial specific volumes
- Molar mass estimations
We can quantitatively judge on:
- Physically meaningful, i.e., absolute molar mass averages and sizes by the hydrodynamic invariant, A0, and / or sedimentation parameter, ßs
- Chain conformational properties of polymers
- Polymer architectures
- Hydrodynamic volumes
- Hydration of objects in solution
- Nanoparticle sizes (hydrodynamic radii and radii of gyration)
Representative example publications:
Ilya Anufriev, Stephanie Hoeppener, Ivo Nischang*
PEG-Lipids: Quantitative study of unimers and aggregates thereof by the methods of molecular hydrodynamics
Analytical Chemistry 2023, 95, 10795–10802.LinkExternal linkAlexey Lezov, Alexander Gubarev, Tobias Kaiser, Willi Tobaschus, Nikolay Tsvetkov, Ivo Nischang*, Ulrich S. Schubert, Holger Frey, Igor Perevyazko* “Hard” sphere−behavior of “soft”, globular like, hyperbranched poly(glycerol)s – Extensive molecular hydrodynamic and light scattering studies Macromolecules 2020, 53, 9220-9233.LinkExternal link
Mandy Grube, Gizem Cinar, Ulrich S. Schubert, Ivo Nischang*
Incentives of using the hydrodynamic invariant and sedimentation parameter for the study of naturally− and synthetically−based macromolecules in solution
Polymers 2020, 12, 277.LinkExternal linkMandy Grube, Igor Perevyazko, Thomas Heinze, Ulrich S. Schubert, Ivo Nischang*
Revisiting very disperse macromolecule populations in hydrodynamic and light scattering studies of sodium carboxymethyl celluloses
Carbohydrate Polymers 2020, 229, 115452.LinkExternal linkMandy Grube, Vlad Dinu, Henry Lindemann, Friederike Pielenz, Grit Festag, Ulrich S. Schubert, Thomas Heinze, Stephen Harding, Ivo Nischang*
Polysaccharide−valproates: Structure−property relationships in solution
Carbohydrate Polymers 2020, 246, 116652.LinkExternal link -
Analytical Ultracentrifugation (AUC)
We utilize the analytical ultracentrifuge and analytical ultracentrifugation (AUC) as a first principle transport−based method in studying natural and synthetic polymers, polymer−drug conjugates, polymer assemblies, as well as medical nanoparticles. We develop specialty applications aiming at (co)localization of multicomponent systems through multidetection in solution alongside the material−biofluid interactions of soft and disperse matter.
Experimental Techniques
- Sedimentation velocity experiments
- Synthetic boundary experiments
Examples of Study
- Pharmapolymers (PEGs, POxs, LPGs, HPGs)
- (An)isotropic micelle systems
- Polyplexes
- Nanoscale drug delivery systems
- Fate of nanomaterials in human serum
Representative example publications:
Ilya Anufriev, Stephanie Hoeppener, Ivo Nischang*
PEG-Lipids: Quantitative study of unimers and aggregates thereof by the methods of molecular hydrodynamics
Analytical Chemistry 2023, 95, 10795–10802.LinkExternal linkNiklas Hauptstein, Paria Pouyan, Kevin Wittwer, Michael Dirauf, Gizem Cinar, Martina Raschig, Kai Licha, Oliver Scherf-Clavel, Tessa Lühmann, Ivo Nischang, Ulrich S. Schubert, Christian Pfaller, Rainer Haag, Lorenz Meinel*
Polymer selection impacts the pharmaceutical profile of site specifically conjugated Interferon-α2a
Journal of Controlled Release 2022, 348, 881-892.LinkExternal linkOlenka J. Valderrama, Ivo Nischang*
Reincarnation of the analytical ultracentrifuge: Emerging opportunities for nanomedicine
Analytical Chemistry 2021, 93, 15805-15815. (Feature Article)LinkExternal linkKatharina Leer, Gizem Cinar, Jana I. Solomun, Liam Martin, Ivo Nischang*, Anja Traeger*
Core-crosslinked, temperature- and pH−responsive micelles: Design, physico-chemical characterization, and gene delivery application
Nanoscale 2021, 13, 19412-19429.LinkExternal linkJana I. Solomun, Gizem Cinar, Prosper Mapfumo, Friederike Richter, Elisabeth Moek, Franziska Hausig, Liam Martin, Stephanie Hoeppener, Ivo Nischang, Anja Traeger*
Solely aqueous formulation of hydrophobic cationic polymers for efficient gene delivery
International Journal of Pharmaceutics 2021, 593, 120080.LinkExternal linkGizem Cinar, Christoph Englert, Ulrich S. Schubert, Ivo Nischang* Salient features of medical nanoparticles in biological fluids from an analytical ultracentrifuge Nanoscale 2020, 12, 22462-22466.LinkExternal link
Gizem Cinar, Christoph Englert, Marc Lehmann, Ivo Nischang*
In situ, quantitative assessment of nanoscale drug delivery systems in human serum
Analytical Chemistry 2020, 92, 7932-7939.LinkExternal link -
Field−Flow Fractionation and Size-Exclusion Chromatography with Multidetection
We utilize the hydrodynamic volume-based separation process of size-exclusion chromatography (SEC) and the diffusion-based separation process of field-flow fractionation (FFF) to study polymers and colloids in solution. This is to unveil their mass and size-based disperse properties quantified by concentration− and mass−sensitive multidetection as an orthogonal technique to analytical ultracentrifugation (AUC).
Representative example publications:
Gizem Cinar, Jana I. Solomun, Prosper Mapfumo, Anja Traeger, Ivo Nischang*
Nanoparticle sizing in the field of nanomedicine: Power of an analytical ultracentrifuge
Analytica Chimica Acta 2022, 1205, 339741.LinkExternal linkMandy Grube, Vlad Dinu, Henry Lindemann, Friederike Pielenz, Grit Festag, Ulrich S. Schubert, Thomas Heinze, Stephen Harding, Ivo Nischang*
Polysaccharide-valproates: Structure−property relationships in solution
Carbohydrate Polymers 2020, 246, 116652.LinkExternal linkMandy Grube, Igor Perevyazko, Thomas Heinze, Ulrich S. Schubert, Ivo Nischang*
Revisiting very disperse macromolecule populations in hydrodynamic and light scattering studies of sodium carboxymethyl celluloses
Carbohydrate Polymers 2020, 229, 115452.LinkExternal linkAlexey Lezov, Alexander Gubarev, Tobias Kaiser, Willi Tobaschus, Nikolay Tsvetkov, Ivo Nischang*, Ulrich S. Schubert, Holger Frey, Igor Perevyazko* “Hard” sphere-behavior of “soft”, globular like, hyperbranched poly(glycerol)s − Extensive molecular hydrodynamic and light scattering studies Macromolecules 2020, 53, 9220-9233.LinkExternal link
Mandy Grube, Meike N. Leiske, Ulrich S. Schubert*, Ivo Nischang*
POx as an alternative to PEG? A hydrodynamic and light scattering study
Macromolecules 2018, 51, 1905-1916.LinkExternal link -
Liquid Chromatography
We utilize liquid chromatography to address the varying chemistry in polymers, i.e., performing high−resolution separations according to the degree of polymerization as well as (orthogonal) end−group functionality in polymers. This is particular important for quantitative analysis of polymerization reactions, desirable terminal functionality, and for utilizing the materials in conjugation reactions. Next to the analysis of polymers, a specialty technique developed in collaboration with our partners concerns the compositional analysis of nanoscale drug delivery systems.
Representative example publications:
Nora Engel, Michael Dirauf, Justyna Czaplewska, Ivo Nischang, Michael Gottschaldt, Ulrich S. Schubert* Determination of ω–end functionalities in tailored poly(2–alkyl–2–oxazoline)s by liquid chromatography and mass spectrometry Royal Society Open Science, 2024, 11, 231008.LinkExternal link
Ekaterina Tsarenko, Ulrich S. Schubert*, Ivo Nischang*
Nanoparticle formulation composition analysis by liquid chromatography on reversed-phase monolithic silica
Analytical Chemistry 2023, 95, 565-569.LinkExternal linkMichaela Brunzel, Michael Dirauf, Martin Sahn, Justyna A. Czaplewska, Nicole Fritz, Christine Weber, Ivo Nischang*, Ulrich S. Schubert*
On the identification and quantification of proton−initiated species in the synthesis of poly(2-alkyl-2-oxazoline)s by high resolution liquid chromatography
Journal of Chromatography A 2021, 1653, 462364.LinkExternal linkMichaela Brunzel, Tobias Majdanski, Jürgen Vitz, Ivo Nischang*, Ulrich S. Schubert*
Fast screening of diol impurities in methoxy poly(ethylene glycol)s (mPEG)s by liquid chromatography on monolithic silica rods
Polymers 2018, 10, 1359.LinkExternal link