The Leibniz Institute of Polymer Research Dresden in Dresden (German: Leibniz-Institut für Polymerforschung) – in short IPF Dresden – is a non-university research institute and a member of the Gottfried Wilhelm Leibniz Scientific Community. The IPF is carrying out fundamental as well as application-oriented research in all areas of polymer science and investigates polymer materials with new or improved characteristics. In the material development, emphasis is given to nanotechnological aspects as well as to biosystem interfaces.
Thin films of auto-oxidized dopamine, the so-called polydopamine (PDA), have been introduced as universal bioinspired "green" adhesion promoter for a variety of applications. This study investigates the effect of different alkaline solutions on PDA films on polyethylene fibers over a time ranging from 1 h to 67 days. On one hand, this supports the application of adhesive PDA films in alkaline media such as cementitious matrices. On the other hand, a controlled chemical decomposition or degradation can be used to reverse adhesion and separate the components of PDA-mediated composite materials for re-use and recycling. The effect of the surface modification and the alkaline treatments was studied using atomic force microscopy, electrokinetic measurements, and spectroscopic techniques. Depending on the composition of the alkaline solution, a progressive dissolution or depolymerization of PDA aggregates was observed. Zeta potential measurements detected, however, acidic groups on the fiber surface even after alkaline treatment for 67 days, indicating that the PDA film was not fully removed.
The limitations of electrical neuromodulation are driving the development of neuroprosthetic systems enhanced with complementary modalities. A key technological challenge however remains the integration of the necessary hardware components (optical, thermal, fluidic, electrical) into miniaturized implants. Here we present a design framework, inspired by fast prototyping, that promises to reduce the complexity, fabrication time, and device bulk of multimodal neural interface systems. By combining extrusion-based 3D printing of silicones and discrete electronic components, we integrated thermal neuromodulation and electrical recording capabilities in soft packages suitable for placement on the cortical surface of rodents. When linked to an autonomous auxiliary driver unit, these packages establish rapid, stable and localized hypothermia together with ElectroCorticoGraphy (ECoG) recording. In a rodent model of epilepsy (4-aminopyridine), we demonstrate hypothermia-induced suppression of seizure-like activity. Our approach may advance the clinical translation of focal hypothermia as an alternative therapy for drug-resistant focal epilepsies.
The origin of life remains a scientific mystery, particularly the emergence of protocells. One hypothesis proposes that protocells arose as droplets formed via liquid-liquid phase separation of polymers. The work on this hypothesis leaves open how protocells survived in fluctuating or cyclic environments. We consider a model system incorporating both spontaneous polymerization and droplet-facilitated fuel-driven polymerization. We show that the resulting droplets display a stationary hysteresis with respect to available fuel. Droplets can remain stable even after the fuel-driven polymerization reactions significantly diminish, suggesting a potential mechanism for protocell formation and resilience to environmental fluctuations. This robustness would have enabled protocells to endure early environmental challenges, such as energy shortages in a famine.
Precise mapping of structural heterogeneity at the sub-10 nm scale is pivotal for rational nanoparticle design, yet conventional analytical workflows remain inadequate. Here we integrate dilution-controlled asymmetric flow field-flow fractionation (AF4) with small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) to interrogate ellipsoidal solid-liquid lipid nanoparticles (LNPs). The dilution-controlled AF4 mode amplifies scattering contrast, enabling robust, shape-resolved analysis across entire elution profiles. Coupling AF4 to SANS in D2O further sharpens resolution for the smallest fractions by reducing particle diffusion through increased solvent viscosity. Comparative sizing shows that SAXS/SANS accurately capture primary particles down to ∼5 nm, whereas multi-angle light scattering chiefly detects loosely associated aggregates. Morphology profiling reveals that surfactant identity governs particle shape, polydispersity, and overall architecture. Joint SAXS/SANS modeling uncovers a 2-3 nm polar shell enveloping an internal core-shell morphology. Together, these insights refine our understanding of LNP size, morphology and drug localization and establish dilution-controlled AF4-SAXS/SANS as a high-resolution platform for dissecting complex nanoparticle systems relevant to biomedical applications.
Biomolecular condensates formed by liquid-liquid phase separation organize many cellular processes, yet it remains unclear how condensate localization is coupled to protein synthesis. In particular, proteins are often translated on polysomes, where multiple ribosomes on a single mRNA generate a bottlebrush-like assembly of nascent chains, raising the possibility that translation itself could be spatially coupled to condensates. Here we develop a theoretical framework for CoTranslational Condensation (CTC), in which nascent chains on a polysome for condensate proteins interact with their condensate and thus localize translation there. Using coarse-grained simulations, we show that protein domain architecture dictates the thermodynamics of CTC, consistent with a Langmuir adsorption model. Proteins with high-affinity regions exposed early on nascent chains display much stronger condensate association than architectures in which these regions appear only late in translation. A bioinformatic analysis of 7667 condensate-associated proteins further shows that sequence architectures compatible with strong CTC are common. At the dynamical level, combining simulations with reaction-diffusion modeling reveals that CTC is kinetically feasible within typical polysome lifetimes, either through densely packed polysomes nucleating new condensates or via diffusion to preexisting condensates. As an illustrative consequence, we show that CTC can reduce the accumulation of unmodified protein intermediates by localizing their synthesis with condensates, where modification can occur promptly. Together, our results establish physical principles for how translation can couple to phase separation and identify protein architectures and cellular regimes that favor CTC.
