Article
Physics, Multidisciplinary
Pierre Rizkallah, Alessandro Sarracino, Olivier Benichou, Pierre Illien
Summary: In this study, the diffusion coefficient of an active tracer in a crowded environment with hardcore interactions is calculated. A closure approximation method is proposed to accurately determine the diffusion coefficient for an arbitrary density of crowders in the system, capturing non-equilibrium effects. The approach also allows the characterization of environment perturbations induced by the movement of the active tracer. The asymptotic regimes of low and high densities are considered to obtain explicit expressions for the diffusion coefficient.
PHYSICAL REVIEW LETTERS
(2022)
Article
Nanoscience & Nanotechnology
D. Izzo
Summary: The aim of this study is to describe the diffusion coefficient of neutral rods in a mixture of rods and spheres in solution. The study considers different situations based on the partial volume fractions and relative sizes of the two types of colloids. Scaling analyses are used to determine either the translational or the rotational diffusion coefficient. The predictions are compared with experimental and numerical data, showing good agreement. The significance of this work lies in providing models that capture the key features of rod diffusion in mixed colloidal solutions, and establishing connections with the more complex problem of diffusion in crowded media, such as the cytoplasm.
Article
Chemistry, Physical
Stepan Timr, Simone Melchionna, Philippe Derreumaux, Fabio Sterpone
Summary: Macromolecular crowding affects protein mobility and intracellular processes. Molecular models are needed to describe crowded environments. OPEPv7 is a force field for rigid-body simulations of crowded protein solutions. It successfully reproduces diffusion slowdown and allows the study of protein assembly dynamics and computational rheology of protein solutions.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Ashley K. Borkowski, Zeke A. Piskulich, Ward H. Thompson
Summary: In this study, the impact of different halide anions on the water diffusion coefficient and activation energy was investigated through molecular dynamics simulations. It was found that water diffusion accelerates down the halide group from F- to I-. The behavior of the diffusion activation energy is complex, with Na+ showing a larger effect than any of the anions, and water molecules in the ion's solvation shell exhibiting a decrease in activation energy.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Mechanics
Kyunil Rah
Summary: Apart from describing the transport behaviors to a reliable accuracy, it remains as yet far from satisfactory to comprehend the explicit role of the solvent-colloid interaction on the diffusivity and viscosity of colloidal hard-sphere suspensions. In this study, we use statistical mechanics to investigate the influence of the free volume effect on the diffusivity and viscosity. The theory predicts a crossover in the solvent effect on the diffusivity, with the solvent-colloid interaction either enhancing or inhibiting diffusion depending on the colloidal concentration.
Article
Thermodynamics
Mate Erdos, Michalis Frangou, Thijs J. H. Vlugt, Othonas A. Moultos
Summary: Cyclodextrins are widely used in various applications, and this study investigated the diffusion of native alpha-, beta- and gamma-CDs in aqueous solutions through Molecular Dynamics simulations. The study found that system size and water force field can affect the computed self-diffusivity of CDs, and different force field combinations can accurately predict the diffusion coefficients of CDs. Additionally, simulations using different force fields showed varying results in terms of ion affinity and diffusivity of CDs in aqueous-NaCl solutions.
FLUID PHASE EQUILIBRIA
(2021)
Article
Chemistry, Physical
Ganghee Park, Hyangseok Lee, Jae Hyun Sim, Ahyun Kim, Myungwoong Kim, Keewook Paeng
Summary: In this study, an approach to examine local segmental dynamics of a polymer near the interface of an inorganic filler was demonstrated by observing the rotational dynamics of fluorescent probes attached to the ends of polymer brushes. The localization of the probes was achieved by designing and synthesizing fluorophore-tethered polystyrene brushes on the surface of controlled-sized silica particles. By controlling the molecular weight and density of the grafted polymer chains, the observed dynamics were not affected by the polymer brush conformation and brush-matrix polymer entanglement. It was found that the polymer dynamics near the interface in the inorganic/polymer composite geometry remained unchanged when there was no interaction between the surface and the matrix polymer.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Polymer Science
Farshad Safi Samghabadi, Ali H. Slim, Maxwell W. Smith, Maede Chabi, Jacinta C. Conrad
Summary: The structure and dynamics of polyelectrolytes have different effects on the transport of anisotropic particles compared to neutral polymers. This study investigates the transport of semiflexible M13 bacteriophage in aqueous solutions of sodium polystyrenesulfonate with varying ionic strengths. The results show non-Gaussian distributions of particle displacements and the presence of multiple diffusive modes.
Article
Polymer Science
Guanchun Rui, Elshad Allahyarov, John J. Thomas, Philip L. Taylor, Lei Zhu
Summary: A new theoretical approach was developed to determine the dipole characteristics of PVDF using broadband dielectric spectroscopy, revealing an increase in active dipole concentration and mobility as temperature increased. This led to higher permittivity and piezoelectric performance in both unpoled and poled PVDF.
Article
Chemistry, Physical
Daniel Gaertner, Julia Kundin, Neelamegan Esakkiraja, Jasper Berndt, Adeline Durand, Josua Kottke, Stephan Klemme, Guillaume Laplanche, Gunther Eggeler, Gerhard Wilde, Aloke Paul, Ingo Steinbach, Sergiy V. Divinski
Summary: Diffusion behavior in the CoCrFeMnNi high-entropy alloy is investigated using an augmented tracer/interdiffusion couple approach. A consistent composition-dependent diffusion database is established, and a pair-diffusion model is used to describe the tracer diffusion and chemical concentration profiles. The uphill diffusion of Co observed in the experiment cannot be explained by existing kinetic and thermodynamic databases, and the vacancy wind effect is found to have a strong influence on intrinsic cross diffusion coefficients.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Fluids & Plasmas
Xudong Wang, Yao Chen
Summary: A recent observation in many biological and active matter systems is the occurrence of a Brownian yet non-Gaussian phenomenon. This paper proposes the main idea of introducing a random diffusivity in an inhomogeneous environment to explain this phenomenon, and utilizes a Langevin system to describe particle motion in complex media. By deriving the general expressions of ensemble- and time-averaged mean-squared displacements, as well as obtaining the analytical expressions of the ergodicity breaking parameter and probability density function of the time-averaged mean-squared displacement for specific time-dependent diffusivity, the results indicate the nonergodicity of the random diffusivity model with any type of diffusivity, including the critical case of normal diffusion.
Article
Polymer Science
Parveen Kumar, Joshua Tamayo, Ruei-Feng Shiu, Wei-Chun Chin, Arvind Gopinath
Summary: Mucus, composed of glycosylated mucins, is a complex material that lines mammalian respiratory, reproductive, and gastrointestinal tracts. It serves as a barrier against harmful microbes and pollutants. The transport and dispersion of particles in mucin gels and solutions differ from small molecules due to interactions with the mucin network.
Article
Physics, Fluids & Plasmas
Leila Abbaspour, Stefan Klumpp
Summary: Living systems contain active particles that can enhance the diffusion of passive particles through their active motion. The density and activity of active particles affect the passive tracer particle diffusion. Additionally, clustering of active particles can suppress the enhanced diffusion of passive particles.
Article
Physics, Multidisciplinary
Amit Sharma, Sumit Sharma
Summary: This study investigates the effect of temperature on water diffusion in polyurethane and polytetrafluoroethylene, as well as the role of graphene reinforcement in water molecule diffusion. The results show that higher temperatures increase the mobility of polymeric chains, resulting in smoother paths for water molecule travel and increased diffusion. Compared with neat PU and PTFE systems, the diffusion of water molecules is significantly reduced in graphene-reinforced systems, with reductions of 79-93% in PU systems and 58-62% in PTFE systems.
Article
Chemistry, Physical
Mohammad R. Momeni, Zeyu Zhang, David Dell'Angelo, Farnaz A. Shakib
Summary: Molecular dynamics simulations combined with periodic electronic structure calculations were used to study the adsorption of water in 1D channels of 2D layered electrically conductive metal-organic frameworks. The results showed stronger van der Waals interactions in Cu-3(HTTP)(2) which led to water preferentially adsorbed on the framework walls.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Thorben Gwydion Jaik, Ulrich Jonas
Summary: This study investigates the thermally dependent absorption behavior of acrylamide derivatives using spectroscopic methods. The results show that the behavior is influenced by the formation of hydrogen bonds between molecules. This finding provides a new theoretical basis for the study of thermo-halochromism.
Article
Chemistry, Multidisciplinary
Nils-Jorgen K. Dai, Gabriela Schaefer, Andrew M. Thompson, Sascha Schmitt, Natalja Redinger, Noelia Alonso-Rodriguez, Kerstin Johann, Jessica Ojong, Jens Wohlmann, Andreas Best, Kaloian Koynov, Rudolf Zentel, Ulrich E. Schaible, Gareth Griffiths, Matthias Barz, Federico Fenaroli
Summary: Tuberculosis is a deadly bacterial disease that threatens millions of lives each year. In this study, polymeric micelles were used to encapsulate four derivatives of the antitubercular drug pretomanid, which showed better in vivo activity against Mycobacterium tuberculosis. These micelles overcame the hydrophobicity and limited bioavailability of the compounds, reducing toxicities and improving therapeutic outcomes.
JOURNAL OF CONTROLLED RELEASE
(2023)
Article
Chemistry, Multidisciplinary
Sajjad Shumaly, Fahimeh Darvish, Xiaomei Li, Alexander Saal, Chirag Hinduja, Werner Steffen, Oleksandra Kukharenko, Hans-Juergen Butt, Ruediger Berger
Summary: State-of-the-art contact angle measurements usually involve image analysis of symmetric, sessile drops. However, analyzing videos of drops sliding down a tilted plate is challenging due to low resolution and changing contact angles. To address this, we propose a 4-segment super-resolution optimized-fitting (4S-SROF) method that combines deep learning-based super-resolution and polynomial fitting. Experimental results show that our method improves contact angle accuracy by 21% for angles lower than 90 degrees and by 33% for angles higher than 90 degrees.
Article
Mechanics
Diego Diaz, Xiaomei Li, Pravash Bista, Xiaoteng Zhou, Fahimeh Darvish, Hans-Juergen Butt, Michael Kappl
Summary: We investigated the charge separation of bouncing drops on hydrophobic surfaces and found that it can be significantly higher than on superhydrophobic surfaces. The presence of self-generated electrostatic forces between the drop and the surface was observed, affecting the rebounding height and retraction motion of the drops. Our calculations showed that these electrostatic forces can be stronger than gravity, reducing the restitution coefficients up to 50%. This new approach provides an advantage compared to other methods for drop charge detection that require more complex setups.
Article
Chemistry, Physical
Patrick Kreissl, Christian Holm, Rudolf Weeber
Summary: Magnetic nanoparticles couple to polymeric environments through various mechanisms, including van der Waals, steric, hydrodynamic, and electrostatic forces. This leads to interesting effects and potential applications, although the details of the coupling are often unknown. Previous work has shown that hydrodynamic coupling alone can explain observed trends in magnetic AC susceptibility spectra for spherical particles. Now, this publication focuses on the interplay of steric and hydrodynamic interactions in non-spherical particles and their coupling to a polymer suspension.
Article
Multidisciplinary Sciences
Shen Han, Richard da Costa Marques, Johanna Simon, Anke Kaltbeitzel, Kaloian Koynov, Katharina Landfester, Volker Mailaender, Ingo Lieberwirth
Summary: Protein corona formation on nanoparticles in biological environments plays a crucial role in determining endocytosis, cellular processes, and drug release. However, little is known about the fate of the protein corona inside cells. This study demonstrates the separation and different processing of nanoparticles and protein corona within different cellular compartments, leading to the conclusion that nanoparticles are prepared for subsequent exocytosis while the protein corona remains in the cell and is ultimately metabolized.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Tobias A. A. Bauer, Jonas Schramm, Federico Fenaroli, Svenja Siemer, Christine I. I. Seidl, Christine Rosenauer, Regina Bleul, Roland H. H. Stauber, Kaloian Koynov, Michael Maskos, Matthias Barz
Summary: The efficient manufacturing techniques are necessary for translating innovative nanomaterials into medical products, requiring large-scale high-throughput synthesis with high reproducibility. A continuous flow process is reported for synthesizing pro-drug-loaded core cross-linked polymeric micelles, combining the commonly separated steps into a single process. The microfluidic process allows the production of spherical micelles with low polydispersity values, avoiding toxic solvents and additives. The formed paclitaxel-loaded CCPMs possess pH-responsive release and show improved toxicity profile and therapeutic efficiency.
ADVANCED MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Maximilian Scherger, Yannick A. Pilger, Judith Stickdorn, Patric Komforth, Sascha Schmitt, Kaloian Koynov, Hans Joachim Raeder, Lutz Nuhn
Summary: The reversible addition-fragmentation chain-transfer (RAFT) polymerization allows the synthesis of biocompatible and functional macromolecules for polymer-drug conjugates. By utilizing traceless linkers, the drug conjugates can be reversibly attached to and released from the polymer chain. This approach is particularly relevant for poly(N,N-dimethylacrylamide) (pDMA), which has shown similar properties to poly(ethylene glycol) (PEG) in improving drug pharmacokinetics and bioavailability. The incorporation of various functionalities in a one-pot reaction procedure has been demonstrated, along with reversible conjugation and traceless release. Moreover, the internalization of polymer-drug conjugates at the cellular level has been achieved using cholesterol-modified RAFT chain-transfer agents.
Article
Multidisciplinary Sciences
Chao Zhu, Till Fuchs, Stefan A. L. Weber, Felix. H. Richter, Gunnar Glasser, Franjo Weber, Hans-Juergen Butt, Juergen Janek, Ruediger Berger
Summary: The growth of lithium dendrites in inorganic solid electrolytes is a major obstacle to the development of reliable all-solid-state lithium metal batteries. The role of grain boundaries in the nucleation and dendritic growth of metallic lithium is not fully understood, but they have been found to be present in post mortem measurements of battery components.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Chien-Hua Tu, Martin Steinhart, Ruediger Berger, Michael Kappl, Hans-Juergen Butt, George Floudas
Summary: By confining semicrystalline polymers within nanoscopic cylindrical pores, they can flow at temperatures below the melting point with intermediate viscosity between the melt and crystal states. This unexpected enhancement in flow, while preserving the polymer crystallites, is important for designing polymer processing conditions applicable at low temperatures, such as for cold drawn polymers like polytetrafluoroethylene, self-healing materials, and nanoconfined donor/acceptor polymers used in organic electronics.
Article
Biochemistry & Molecular Biology
Tobias A. A. Bauer, Irina Alberg, Lydia A. A. Zengerling, Pol Besenius, Kaloian Koynov, Bram Slutter, Rudolf Zentel, Ivo Que, Heyang Zhang, Matthias Barz
Summary: Core cross-linked polymeric micelles (CCPMs) are designed to improve the therapeutic profile of hydrophobic drugs, reduce or completely avoid protein corona formation, and offer prolonged circulation times. CCPM stability was tuned by using bifunctional or trifunctional cross-linkers and varying the cross-linkable polymer block length. The circulation time and biodistribution of CCPMs can be enhanced by using trivalent peptide cross-linkers.
Article
Multidisciplinary Sciences
Xiaomei Li, Francisco Bodziony, Mariana Yin, Holger Marschall, Ruediger Berger, Hans-Juergen Butt
Summary: Liquid drops sliding on tilted surfaces is a common phenomenon with significant industrial applications. Despite its importance, predicting the sliding velocity of the drops is currently impossible. In this study, we measured various parameters of sliding liquid drops on inclined flat surfaces made of different materials, and found that the friction force can be described empirically by a specific equation for a certain velocity range. The dimensionless friction coefficient, which varies between 20 to 200, is a material-specific parameter that is necessary for understanding dynamic wetting.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Youmin Hou, Prexa Shah, Vassilios Constantoudis, Evangelos Gogolides, Michael Kappl, Hans-Juergen Butt
Summary: Membrane distillation (MD) is a new desalination technology that utilizes phase change to separate water vapor from saline based on low-grade energy. A super liquid-repellent membrane with hierarchical porous structures has been developed to address the conflicting requirements of membrane design. The membrane improves distillation flux by up to 60% and exhibits excellent salt rejection and operating stability. This approach has broad applications beyond desalination, such as wastewater treatment.
NATURE COMMUNICATIONS
(2023)
Article
Pharmacology & Pharmacy
Maximilian Scherger, Yannick A. A. Pilger, Judith Stickdorn, Patric Komforth, Sascha Schmitt, Sana M. M. Arnouk, Els Lebegge, Kaloian Koynov, Hans-Joachim Rader, Jo A. A. Van Ginderachter, Lutz Nuhn
Summary: In this study, a procedure is demonstrated for site-specific reversible bioconjugation of genetically engineered single domain antibodies, called nanobodies, using self-immolative linkers (SILs). The flow cytometry and microscopy images confirm cellular uptake and biological affinity of the modified nanobodies. This strategy can be extended to other therapeutically relevant representatives of nanobodies, highlighting the versatility of this reversible reductive-responsive bioconjugation in a broad field of applications.
ADVANCED THERAPEUTICS
(2023)
Article
Computer Science, Artificial Intelligence
Samuel Tovey, Sven Krippendorf, Konstantin Nikolaou, Christian Holm
Summary: This work introduces two collective variables, entropy and trace of the empirical neural tangent kernel, and empirically analyzes their correlation with the performance and generalization of neural networks. The framework is also applied to the problem of optimal data selection and shows that random network distillation can outperform random selection.
MACHINE LEARNING-SCIENCE AND TECHNOLOGY
(2023)
