Publikationen

Enterococcus faecalis is a commensal bacterium in the human gut, but it can also cause life-threatening diseases, especially serious hospital-acquired infections. Bacteria release particles called extracellular vesicles (EVs), which help them interact and communicate with other cells, including bacteria and human cells. However, it is unclear how EVs produced by E. faecalis (Ef-EVs) affect the host immune system. In this study, we investigated how Ef-EVs affect immune and endothelial cells. We found that Ef-EVs activate inflammatory responses through a receptor on the cell surface, without the need to be taken up by the cells. In addition, Ef-EVs altered the metabolism of immune cells, shifting them towards a state that supports inflammation. These findings highlight a previously underexplored mechanism by which Gram-positive bacterial EVs can shape host immunity and cellular metabolism, thereby advancing our understanding of host-pathogen interactions.

In engineered living materials (ELMs) made of genetically engineered bacteria embedded in polymeric matrices, it is desirable for the bacteria to remain contained for biosafety and reliable performance. Such ELMs are being explored for a variety of applications, including smart drug delivery, in which the material also needs to allow protein release. Achieving this balance requires materials that simultaneously support cell viability, prevent bacterial escape, and permit controlled molecular diffusion. Here, we systematically dissect how alginate cross-linking chemistry, buffer composition, and secondary network reinforcement shape the performance of core–shell beads encapsulating Escherichia coli Nissle 1917 engineered to secrete a model protein. We identify a 4 h Ca2+ cross-linking window as the upper limit that maintains robust core viability and week-long confinement. For improved confinement, additional cross-linking strategies, including glutaraldehyde, polyethylenimine, and tannic acid, were tested and found to enhance the shell’s barrier properties to prevent leakage for up to 15 days but also negatively impacted protein release. Finally, replacing Ca2+ with Ba2+ as the cross-linking divalent cation yields the most effective solution, producing beads with exceptional long-term bacterial confinement capability (>20 days) while allowing for comparable protein secretion levels to Ca2+ controls. Together, these results establish a a materials-centric design framework for fabricating alginate-based ELMs that achieve durable confinement without compromising functional protein output and highlight barium-alginate shells as a promising platform for fabricating ELMs toward therapeutic applications.

The agglomeration of apolar metallic nanoparticles (NPs) brings them within nanometer distances, enabling nonradiative coupling through electron conduction tunneling and plasmonic interactions. Even stronger coupling can be achieved with metallic connections between the particles. Thermally induced coarsening is often used to join particles in this way, but typically requires high temperatures. For example, the thermal coarsening of thiol-coated NPs in apolar dispersions requires heating above 120 °C to induce ligand desorption. This leads to side reactions, notably Ostwald Ripening and the formation of small particles. Here, we introduce a new method for controlled NP coarsening in apolar dispersions at near-ambient conditions. Small amounts of reactive chemical additives are added to the dispersion and thermally activated. Transmission electron microscopy and small-angle X-ray scattering reveal that adding the cyclic sulfide additive molecule tetrahydrothiophene (R5S) to a dispersion of hexadecanethiol (HDT)-coated gold nanoparticles (AuNPs) induces aggregation at temperatures as low as 40 to 60 °C. The cores form metallic joints, forming larger continuous gold bodies. An Arrhenius analysis of the temperature-dependent aggregation kinetics identifies the exchange of HDT to R5S on the gold surfaces as the rate-limiting step. Small-angle neutron scattering and thermogravimetry confirm the mechanism and indicate that ∼80% of HDT is replaced by R5S after 5 h at 50 °C. Progressive ligand exchange reduces the steric repulsion by the shells until aggregation sets in. A comparison with the larger cyclic sulfide thionane and the cyclic amine pyrrolidine, which do not induce coarsening, shows that the prerequisite for ligand desorption at moderate temperatures to enable AuNP coarsening is a small size and strong affinity of the additives to the gold surfaces.

Stress granules (SGs) are biomolecular condensates that form transiently in the cytosol of mammalian cells in response to stress. Dysregulation of their assembly or disassembly is implicated in human age-related diseases. While phase separation is the key process underlying SG assembly, understanding of their function, composition and regulation in response to physiological stimuli is limited. This knowledge gap reflects the challenge of gaining comprehensive and quantitative insights into the dynamic regulation of the complex composition of SGs at the single-cell level. Here we present an emulsion-based microfluidics method to overcome this limitation. “Cytosolic extracts-in-oil droplets” (CEODs) recreate a confined active cytosolic milieu that undergoes phase separation and SG formation in response to stress under physiological conditions. This approach led to the discovery of seven previously unrecognised SG components involved in signalling pathways. CEODs provide a versatile and cost-effective screening platform for future mechanistic and therapeutic studies.

Engineering cells to fabricate and program bio-based materials presents a sustainable alternative to petroleum-derived composites while simultaneously enabling the integration of advanced functionality. This is particularly relevant for engineered wood composites, which are widely used in construction, yet rely on petrol-based, non-biodegradable binders. Here, we develop bio-programmed wood composites using engineered bacteria, addressing both functional enhancement and sustainability. To navigate the large design space linking genetic programs, material composition, and processing conditions to mechanical performance, we combine lab automation with a pretrained transformer model for in-context prediction. This approach enables rapid identification of formulations yielding desired mechanical properties. Beyond mechanical properties, we introduce programmable features such as optogenetically patterned in situ pigmentation, local porosity control, and autonomous damage reporting. We demonstrate the applicability of our approach through manufacturing macro-scale furniture prototypes. Our platform establishes a blueprint for the accelerated, AI-driven development of sustainable, living multifunctional materials with applications in construction and beyond.

Nanodiamonds hosting colour centres are promising building blocks for quantum technologies, enabling advances in quantum computation1,2, nanoscale NMR spectroscopy3,4,5,6, single-spin magnetometry7,8, wide-field quantum imaging9 and single-photon sources10,11. However, the controlled bottom-up synthesis of ultrasmall and structurally uniform nanodiamonds has remained a challenge, with existing methods producing heterogeneous materials that vary in size, morphology, impurity content and defect quality. Here we show that well-defined, hydrogen-terminated molecular nanographenes serve as chemically confined precursors for high-pressure, high-temperature synthesis of ultrasmall (3–4 nm), monodisperse and highly crystalline molecular nanodiamonds with only a single sp2 surface reconstruction and produced on a milligram scale. The same bottom-up platform also enables a two-component strategy for incorporating silicon- and germanium-based colour centres during synthesis, yielding SiV− and GeV− emitters without ion implantation, irradiation or post-treatment. Because the nanographene precursor defines both the confined carbon framework and the hydrogen content, this approach provides intrinsic, precursor-level control over nanodiamond size and composition, particularly in the low-nanometre regime relevant for biological and quantum sensing. Molecular nanographenes, ultralarge polycyclic aromatic hydrocarbons, therefore, establish a scalable and modular route to high-quality molecular and fluorescent nanodiamonds and offer a general design principle for tailored quantum materials and nanoscale devices.

The functional integration of biological switches with synthetic building blocks enables the design of modular, stimulus-responsive biohybrid materials. By connecting the individual modules via diffusible signals, information-processing circuits can be designed. Such systems are, however, mostly limited to respond to either small molecules, proteins, or optical input thus limiting the sensing and application scope of the material circuits. Here, a highly modular biohybrid material is design based on CRISPR/Cas13a to translate arbitrary single-stranded RNAs into a biomolecular material response. This system exemplified by the development of a cascade of communicating materials that can detect the tumor biomarker microRNA miR19b in patient samples or sequences specific for SARS-CoV. Specificity of the system is further demonstrated by discriminating between input miRNA sequences with single-nucleotide differences. To quantitatively understand information processing in the materials cascade, a mathematical model is developed. The model is used to guide systems design for enhancing signal amplification functionality of the overall materials system. The newly designed modular materials can be used to interface desired RNA input with stimulus-responsive and information-processing materials for building point-of-care suitable sensors as well as multi-input diagnostic systems with integrated data processing and interpretation.

Background: Intima proliferation and in-stent restenosis is a challenging situation in interventional treatment of small vessel obstruction. Al/Al2O3 nanowires have been shown to accelerate vascular endothelial cell proliferation and migration in vitro, while suppressing vascular smooth muscle cell growth. Moreover, surface modification of Al/Al2O3 nanowires with poly[bis(2,2,2-trifluoromethoxy)phosphazene (PTFEP) coating enables further advantages such as reduced platelet adhesion. Therefore, the study's goal was to compare the biocompatibility of novel Al/Al2O3 + PTFEP coated nanowire bare-metal stents to uncoated control stents in vivo using optical coherence tomography (OCT), quantitative angiography and histomorphometric assessment. Methods: 15 Al/Al2O3 + PTFEP coated and 19 control stents were implanted in the cervical arteries of 9 Aachen minipigs. After 90 days, in-stent stenosis, thrombogenicity, and inflammatory response were assessed. Scanning electron microscopy was used to analyse the stent surface. Results: OCT analysis revealed that neointimal proliferation in Al/Al2O3 + PTFEP coated stents was significantly reduced compared to control stents. The neointimal area was 1.16 ± 0.77 mm2 in Al/Al2O3 + PTFEP coated stents vs. 1.98 ± 1.04 mm2 in control stents (p = 0.004), and the neointimal thickness was 0.28 ± 0.20 vs. 0.47 ± 0.10 (p = 0.003). Quantitative angiography showed a tendency to less neointimal growth in coated stents. Histomorphometry showed no significant difference between the two groups and revealed an apparent inflammatory reaction surrounding the stent struts. Conclusions: At long-term follow-up, Al/Al2O3 + PTFEP coated stents placed in peripheral arteries demonstrated good tolerance with no treatment-associated vascular obstruction and reduced in-stent restenosis in OCT. These preliminary in vivo findings indicate that Al/Al2O3 + PTFEP coated nanowire stents may have translational potential to be used for the prevention of in-stent restenosis.

Supercapacitors are efficient and versatile energy storage devices, offering remarkable power density, fast charge/discharge rates, and exceptional cycle life. As research continues to push the boundaries of their performance, electrode fabrication techniques are critical aspects influencing the overall capabilities of supercapacitors. Herein, we aim to shed light on the advantages offered by dry electrode processing for advanced supercapacitors. Notably, our study explores the performance of these electrodes in three different types of electrolytes: organic, ionic liquids, and quasi-solid states. By examining the impact of dry electrode processing on various electrode and electrolyte systems, we show valuable insights into the versatility and efficacy of this technique. The supercapacitors employing dry electrodes demonstrated significant improvements compared with conventional wet electrodes, with a lifespan extension of +45% in organic, +192% in ionic liquids, and +84% in quasi-solid electrolytes. Moreover, the increased electrode densities achievable through the dry approach directly translate to improved volumetric outputs, enhancing energy storage capacities within compact form factors. Notably, dry electrode-prepared supercapacitors outperformed their wet electrode counterparts, exhibiting a higher energy density of 6.1 Wh cm−3 compared with 4.7 Wh cm−3 at a high power density of 195 W cm−3, marking a substantial 28% energy improvement in the quasi-solid electrolyte.

A low-temperature sintering mechanism of silver microparticles is established and used to enable the design-for-recycling of printed electronics. The formation of necks during the initial phase sintering of precipitated and atomized silver microparticles is studied. Temperature- and time-dependent in-situ analyses indicate the existence of a mobile silver species that provides efficient mass transport. The activation energy of neck formation identifies silver ion formation as the rate-limiting step of low-temperature silver sintering. It is demonstrated that resistivities of 271 times that of bulk silver can be attained after 40 minutes at 150°C. Low-temperature sintering not only reduces the energy required during thermal treatment but it yields layers that are suitable for recycling, too. The resulting layers have conductive necks that are mechanically weak enough to be broken during recycling. Printed layers are redispersed and the recycled silver powder is reused without loss of the electrical performance in new prints. Their conductivities are industrially relevant, which makes this recyclability-by-design approach promising for manufacturing more sustainable printed electronics.