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Oxygen-Inhibition Driven Compartmentalization of Dextran Microgels: Toward Fusible Colloidal Biomaterial Inks for 3D Printing
Item type: Journal Article
Bulut S.; Bissing T.; Lile T.; et al. (2026)
This study presents a facile and versatile method to synthesize tailored, compartmentalized, polysaccharide-based microgels, with ultra-low crosslinked shells for the development of self-setting colloidal biomaterial inks. Compartmentalization is achieved by exploiting spatially controlled oxygen-inhibition of the crosslinking process in droplets obtained by droplet-based microfluidics, leading to physically distinct core and shell regions inside dextran microgels. The shell exhibits a markedly lower cross-linking density, resulting in reduced stiffness, tunable degradation, and higher macromolecular permeability than the core. The facile control of the core-to-shell ratio by varying the initiator concentration and oxygen availability represents a novel strategy to engineer microgel compartmentalization. This work establishes oxygen-controlled photopolymerization as a new design principle for structuring microgels in flow, offering precise spatial control over polymer network architecture without complex templating or multi-phase emulsions. Beyond dextran, this concept is broadly applicable to other acrylated and methacrylated hydrogel systems, opening new avenues for designing hierarchical soft materials. We demonstrate the applicability of these advanced microgels for the fabrication of millimeter-sized tissue constructs, via 3D printing by exploiting the fusion of ultra-low crosslinked shell compartments, thereby eliminating the need for additional chemical crosslinkers, initiators, or support baths to stabilize the final printed constructs.
Micro-and Nanogels at Fluid Interfaces: Single-Particle Properties and Collective Behavior
Item type: Book Chapter
Vialetto J.; Isa L. (2026)
Soft, deformable colloidal particles consisting of swollen crosslinked polymer networks, also known as micro-and nanogels, have seen significant developments in recent decades. In particular, their adsorption, confinement, and assembly at fluid interfaces, e.g. water–oil or water–air interfaces, present great opportunities, both for applications and fundamental studies alike, compared to the case of mechanically rigid particles. Here, we review some of the key aspects of the utilization of micro-and nanogels at fluid interfaces, starting from a discussion of their reconfiguration upon adsorption as a function of their properties, followed by an analysis of the behavior of microgel monolayers. We conclude by discussing some of the many applications for soft particles at interfaces and present some promising directions for future research.
Long-Term Environmental Governance of Wastes—In Search of Decolonizing the Future
Item type: Book Chapter
Flüeler T. (2026)
Some environmental issues (like nuclear waste, other special wastes, or CO 2 storage) are extremely long-lasting, from a thousand to one million years. By that, our societies threaten to colonize the future as today's generations (have to) take long-term decisions without the consent of future ones and without knowing whether they will take over imposed burdens or not. This contribution addresses technical, ethical, and political issues connected with this dilemma and proposes some ways out.
Directed cortico-limbic dialogue in the human brain
Item type: Journal Article
van Maren E.; Mignardot C.G.; Widmer R.; et al. (2026)
How can one trace the brain's orderly directed signals amid a tangle of nerve fibers? Because direct access to actual brain signaling is rare in humans, the precise wiring diagrams for cortico-limbic communication during sleep and wake remain essentially unmapped, hampering progress in neuroscience. Now, a unique neurosurgical window on the human brain allows for electrically mapping cortical connections at the hospital, but studies so far have relied on average signals, masking the dynamic nature of signal flow across brain regions and vigilance states. To causally estimate signal flow, we repeatedly probed cortico-limbic networks with short-lived electrical pulses over days and assessed the variable fate of each transmitted signal on a single-trial basis. In the resulting openly available dataset, we characterized signaling probabilities and directionality across thousands of local and long-range cortico-limbic connections over days. Challenging established views, we found that limbic structures send twice as many signals as they receive, in both wakefulness and sleep. Our findings provide a fundamental framework for causally interpreting signal flow in the brain and formulating therapeutic strategies for brain network disorders.
Laboratory Synthesis and Characterization of Natural Gas Hydrates for Sustainable Gas Production from Hydrate-Bearing Sediments
Item type: Review Article
Golsanami N.; Gyimah E.; Wu G.; et al. (2026)
Natural gas hydrate (NGH) deposits represent a vast and clean energy source. However, sustainable gas production from these resources remains an unsolved technical problem due to potential geohazards and climate challenges. A critical issue in this regard is the difficulty of obtaining in situ samples, which are essential for detailed laboratory studies of NGH’s geomechanical and chemical behavior for safe and green gas production after hydrate dissociation. Currently, the retrieval of representative samples from NGH reservoirs is hindered by significant technological limitations and high costs. Consequently, laboratory-synthesized gas hydrate-bearing sediment (HBS) samples are crucial for controlled research purposes and validating numerical simulation models and are used in the majority of research studies. With this in mind and considering the complexity of synthesizing HBS samples, this study comprehensively reviews different methods of synthesizing gas hydrates in porous media, including excess-gas, excess-water, dissolved-gas, spray, bubble injection, and hybrid techniques. Each method produces distinct hydrate morphologies (e.g., pore-filling, cementing, grain-coating, etc.) and saturation levels, with trade-offs in speed, uniformity, reproducibility, and ease of control. Furthermore, the current review details the synergic application of non-invasive characterization techniques, i.e., X-ray Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR), in studying gas hydrates. CT provides high-resolution three-dimensional (3D) structural images of pore geometry and hydrate distribution, while NMR/MRI (Magnetic Resonance Imaging) quantifies fluid saturations and tracks hydrate formation/dissociation dynamics in real time. The synergistic use of CT and NMR offers a powerful multimodal approach, overcoming individual limitations such as CT’s poor hydrate–water contrast detection and NMR’s indirect hydrate inference, which could help in the sustainable synthesis of particular hydrate morphologies. Finally, the critical analysis of current technological challenges or gaps and also the emerging trends and future directions in the study of HBS, including advanced imaging techniques, AI-assisted analysis, and standardization efforts, etc., are discussed. It was found that the selection of the most appropriate method for natural gas hydrate synthesis is mostly task-specific, and the emerging technologies have facilitated the synthesis of HBS samples with more precise control of morphology, saturation, etc. This review provides the required insights for sustainable synthesis and characterization of hydrate-bearing sediments samples and serves sustainable gas production from natural gas hydrate reservoirs.