Scientific publications

The aggregation of carbon nanofillers within polymer matrices is a crucial phenomenon for the formation of conducting channels in electrically conductive composites. Herein, a systematic comparison of the effect of 1D and 2D carbon nanofillers, exploiting their dimension-dependent aggregation in matrices, is performed. The role of flexible matrix in fractal formation is also highlighted by demonstrating that the presence of polar moieties in a polymer matrix affects the agglomeration geometries of functional carbon nanomaterials. Carboxylic acid derivatives of nanotubes and hydroxylated graphene are incorporated into both “functionally rich” polyurethane and apolar polydimethylsiloxane matrices to explore filler–filler and matrix–filler interactions. The in situ ultra-small-angle X-ray scattering analysis performed with simultaneous conductivity measurements, and stretching of flexible film has established a distinct role for loading fraction of functional nanofillers in deciding the stability of conduction networks. The effect of topological differences in composites is observed to be most striking in the case of sheets, where it is shown that the 2D flakes can bend and unfold upon stress, exclusively affecting the percolation and conductive mechanism in composites. These findings help to select the suitable materials to design the next generation of flexible and wearable electronic devices, offering versatility and adaptability in applications.

In technologies for PFAS removal, one of the biggest challenges is combining high adsorption capacity with excellent regeneration capabilities. In recent years, metallopolymer-based materials have shown promising potential in both aspects. In this work, we present two convenient ways to functionalize organic microparticles with charged, functional moieties (cobaltocenium), either through a one-pot reaction via siloxane-condensation or by straightforward ring-opening reaction of epoxides. After characterization of the novel adsorbent materials by state-of-the-art analytics to verify the successful functionalization, their performance for PFAS adsorption and regeneration was investigated. To gain insight into the adsorption mechanism, experiments were first conducted at low concentrations (20 μg L−1) and in equilibrium, showing adsorption for both materials of up to 97 % for PFOA and PFOS. Furthermore, an increase in adsorption within an ionic matrix of commercial drinking water and an adsorbent preference at different pH values was demonstrated. Analysis of the influence of the concentration indicates multilayer adsorption beyond simple ion-paring, best described by a Brunauer-Emmett-Teller mechanism. Moreover, utilizing a straightforward column setup, the total PFOA capacity is analyzed, revealing a 4–5-fold increase upon functionalization, leading to 215 mg g−1 and 296 mg g−1 PFOA adsorption. Overall, column-based adsorption experiments showed promising results at low (20 μg L−1) and medium (2.25 mg L−1) PFAS concentrations. Finally, reusability and regeneration studies further revealed an excellent desorption performance upon multiple cycles and PFAS elution of up to 88 ± 4 %. © 2025 The Author(s)

Pyrazinones are a growing family of microbial NRPS-derived natural products showing interesting biological
activities. These compounds are characterized by the presence of either a di- or trisubstituted heterocyclic,
nonaromatic 2(1 H)-pyrazinone core in their structure. The most commonly occurring disubstituted pyrazinone
natural products are synthesized through a dipeptide intermediate, which is further cyclized to yield the pyrazinone
moiety. Trisubstituted pyrazinones are seldom found in natural products, with JBIR56 and JBIR57, isolated from
marine Streptomyces, being notable examples. In contrast to the simply organized disubstituted pyrazinones, JBIR56
and JBIR57 are syn-thesized as tetrapeptides with unnatural beta-amino acid residue involved in the for-mation
of the pyrazinone moiety. Despite interesting structural features, biosynthetic routes leading to the production of
these compounds have not been reported yet. Here we report the discovery of new members of trisubstituted
pyrazinone family– tetrapeptides ichizinones A-C in Streptomyces sp. LV45-129. Through sequence analysis and
heterologous expression, a biosynthetic gene cluster encoding ichizinone production was identified. Based on
gene annotation and sequence homology, a biosynthetic model was suggested. The presented results provide
insights into the biosynthesis of rare trisubstituted pyrazinone natural products.

Selective aggregation of gold and silver nanoparticles in water, leading to distinctly coloured states, can be achieved using particles with suitable ligands and bis(cyclodextrins) as the linking units.

Soft electrical components are highly demanded for human-machine interaction devices. “Electrofluids” (EFs), which are suspensions of electrically conductive filler particles in non-conductive solvents, are proposed as promising sensors and conductive materials since they can flow and retain electrical conductivity. As they remain liquid in working conditions, encapsulation and manufacturing of complex patterns remain as a challenge but would enable a wider variety of applications. Direct ink writing (DIW) is proposed here as a method to manufacture carbon-based EFs. Simple shear flow and Fourier-transform (FT) rheology are performed to evaluate the printability of EFs containing different concentrations of Carbon Black and Graphene Powder by DIW. Electrofluids exhibited three important characteristics to be manufactured via DIW: yield stress behavior (confirmed by flow curves), high brittleness, and a fast mechanical recovery within a range of 15 s. Printability maps are created to distinguish printable and non-printable EFs. Printable EFs are used to manufacture complex patterns. As a proof of the great potential of the EFs and DIW combination, a comparison between simple and multiline strain gauges showed an enhancement in the sensitivity of EFs as strain sensors by almost 800%.

The perceived time can shrink or expand for emotional stimuli. Converging evidence suggests that emotional
time distortions are rooted in the emotional states of the timing agents because emotional stimuli can influence
the timing of simultaneous neutral events. As emotional states are transitory, we investigated if time modulating
emotional states also influence timing of subsequent neutral events. In each trial, we induced different valence
and arousal levels by using affective vibrotactile patterns before participants judged the duration of neutral
auditory tones. Compared to neutral patterns, affective patterns modulated participants’ time perception of the
subsequent tones. We observed an interaction between arousal and valence: Pleasant-Low arousal patterns
expanded the timing of subsequent neutral events more than Unpleasant-Low arousal patterns while Pleasant and
Unpleasant-High arousal led to a similar temporal expansion. Our results indicate time modulating effects of
emotional stimuli are due to changed emotional states and influence time perception likely until the underlying
state decays.

The approval of Onpattro® (2018) and Comirnaty (2020) has driven interest in nanoparticulate nucleotide delivery. Newer concepts in gene therapy however, require not only the delivery of one, but multiple nucleotides. Examples are CRISPR/Cas9 gene editing and cancer immunotherapy. However, the current gold standard for nucleotide delivery – lipid nanoparticles – faces significant challenges, including limitations for co-encapsulation and nucleotide-nucleotide interactions. Aim of this study was to design a core-shell system featuring separate encapsulation of two nucleotides via a two-step formulation process. Six distinct cationic polymers were combined with three anionic polymers, resulting in 18 core compositions. Screening of these formulations identified three potent lipopolyplexes (LPPs), which were further evaluated and compared in terms of transfection efficiency, expression kinetics, storage stability, and nebulization performance. Among them, the combination of poly-L-arginine and poly-L-glutamic acid demonstrated the highest overall performance. Our systems enabled precise co-delivery of two model mRNAs in a controlled ratio, demonstrating potential for advanced therapeutic applications. Additionally, the role of mRNA localization within the LPP was investigated. Surface-loaded mRNA demonstrated superior transfection efficiency and shear resistance compared to core-loaded mRNA, which lost functionality under nebulization.

Advances in the past decades in materials science, biofabrication methods, and synthetic biology have given rise to new fields like living materials. A living material is a class of biohybrid composite with living elements, including bacteria, yeasts, fungi, and mammalian cells, integrated with nonliving components. (1−6) These materials combine the advantages of both living and nonliving components to generate novel functions such as responses to environmental parameters and syntheses of complex biomolecules. (7) The nonliving aspect combines diverse chemistries and manufacturing techniques to support or enhance the functions of the living part. (6) Living materials as therapeutics (Living Therapeutic Materials, LTMs) bring revolutionary options to diagnostic and therapeutic practice, offering a solution to life-concerning issues by life itself (Figure 1). Living Therapeutic Materials are revolutionizing classical drug delivery devices, as they can produce therapeutics long-term, in situ, and on demand. This represents a more sustainable way for treatment. To realize Living Therapeutic Materials in the clinic, more preclinical studies need to be carried out so the concerns in terms of safety are well understood and their capacity as a more efficient delivery system is assessed. In the past decade, there has been a rise in the number of proof-of-concept LTMs and yet, the preclinical investigation of these materials is just starting.

The oxidation of triphenylphosphine by perfluorinated phenaziniumF aluminate in difluorobenzene affords hexaaryl-1,2-diphosphonium dialuminate 1. Dication 12+ is valence isoelectronic with elusive hexaphenylethane, where instead the formation of a mixture of the trityl radical and Gomberg’s dimer is favored. Quantum-chemical calculations in combination with Raman/IR spectroscopies rationalize the stability of the P–P bonded dimer in 12+ and suggest, akin to the halogens, facile homolytic as well as heterolytic scission. Thus, 12+ serves as a surrogate of both the triphenylphosphorandiylium dication (Ph3P2+) and the triphenylphosphine radical monocation (Ph3P·+). Treating 1 with dimethylaminopyridine (DMAP) or tBu3P replaces triphenylphosphine under heterolytic P–P bond scission. Qualifying as a superoxidant (E vs Fc/Fc+ = +1.44 V), 1 oxidizes trimethylphosphine. Based on halide abstraction experiments (–BF4, –PF6, –SbCl6, –SbF6) as well as the deoxygenation of triethylphosphine oxide, triflate anions as well as toluic acid, 1 also features Lewis superacidity. The controlled hydrolysis affords Hendrickson’s reagent, which itself finds broad use as a dehydration agent. Formally, homolytic P–P bond scission occurs with diphenyldisulfide (PhSSPh) and the triple bonds in benzo- and acetonitrile. The irradiation by light cleaves the P–P bond homolytically and generates transient triphenylphosphine radical cations, which engage in H-atom abstraction as well as CH phosphoranylation.

During mating in budding yeast, cells use pheromones to locate each other and fuse. This model system has shaped our current understanding of signal transduction and cell polarization in response to extracellular signals. The cell populations producing extracellular signal landscapes themselves are, however, less well understood, yet crucial for functionally testing quantitative models of cell polarization and for controlling cell behavior through bioengineering approaches. Here we engineered optogenetic control of pheromone landscapes in mating populations of budding yeast, hijacking the mating-pheromone pathway to achieve spatial control of growth, cell morphology, cell-cell fusion, and distance-dependent gene expression in response to light. Using our tool, we were able to spatially control and shape pheromone gradients, allowing the use of a biophysical model to infer the properties of large-scale gradients generated by mating populations in a single, quantitative experimental setup, predicting that the shape of such gradients depends quantitatively on population parameters. Spatial optogenetic control of diffusible signals and their degradation provides a controllable signaling environment for engineering artificial communication and cell-fate systems in gel-embedded cell populations without the need for physical manipulation.