INMdok (Leibniz Institute for New Materials)
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Evolution of Ocular Organ‐On‐Chip Systems for Disease Modelling and Drug Testing: Where are We Now?
Full text linkIncreasing aging population, digital screen use, environmental factors, and sleep disorders have contributed to a rise in ophthalmic diseases. This has soared the demand for better ocular models that are more predictive and can be used to identify new pharmacological targets. Traditional models fail to recapitulate organ‐level functionalities and present anatomical differences with human structures, therefore, organ‐on‐chip systems have emerged to tackle these limitations. Microfluidic devices is engineered to provide the layered structure that the ocular tissues require. This is combined with tight regulation of diffusion gradients and perfusion systems for toxicological analysis and drug screening applications. Incorporation of several cellular layers, motion to mimic blinking, or incorporation of ocular organoids in microfluidic devices are some of the advancements that the field has made. This work reviews the evolution of ocular microphysiological systems and discusses some challenges that could be undertaken by the organ‐on‐chip community
Developing an Ontology on Battery Production and Characterization with the Help of Key Use Cases from Battery Research
Full text linkMaterials science research faces challenges due to diverse and evolving measurements, materials, and methods. Managing research data in a way that is understandable, comparable, and reproducible is essential for high data quality, particularly for data science and machine learning applications. In Li-ion batteries research data storage concepts and structures vary widely between institutions and researchers, leading to difficulties in data comparison and understanding. To address the issue of data structuring, battery production and characterization ontology (BPCO) is developed. The ontology builds on existing ontologies like the Platform MaterialDigital core ontology and quantities, units, dimensions, and types ontology to model standard battery production processes, characterization methods, and materials. The BPCO is based on a workflow structure to be accessible to nonexperts and, unlike highly specialized existing ontologies, models the whole production process removing the need for separate data structures and enabling the identification of dependencies between parameters. This work builds upon a previously published paper in which the taxonomy and fundamental strategies for ontology development are established. The article presents the developed ontology and its use for structuring research data in three key use cases, that is, different experiments performed to validate the ontology's capabilities, provide feedback, and ensure its applicability
Optogenetic control of pheromone gradients and mating behavior in budding yeast
Full text linkDuring 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
Synthesis and Self-Assembly of Pore-Forming Three-Arm Amphiphilic Block Copolymers
Full text linkThe synthesis of an amphiphilic three-arm block copolymer (AB)3-BCP, which consists of poly(methyl methacrylate) (PMMA) and poly(butyl methacrylate) (PBMA) in the hydrophobic inner block, is reported. The hydrophilic block segment is based on poly(2-hydroxyethyl methacrylate) (PHEMA) originating from 2-(trimethylsiloxyl)ethyl methacrylate (HEMA-TMS). The preparation is carried out in two steps using a core-first approach. Using atom transfer radical polymerization (ATRP) as a controlled polymerization technique, three (AB)3-BPCs with HEMA contents of 15 to 38 mol−1 % are prepared, applying different reaction conditions. Porous structures are generated from these BCPs by applying a self-assembly and nonsolvent-induced phase separation (SNIPS) protocol. Complex surface structures are observed using scanning electron microscopy (SEM). Bulk morphologies are investigated for a better understanding of the underlying self-assembly. For PHEMA-rich (AB)3-BCPs, non-regular lamellar microphases are observed in transmission electron microscopy (TEM) and confirmed by small-angle X-ray scattering (SAXS). The porous structures and their expected swelling characteristics are analyzed using atomic force microscopy (AFM) in air and water. Time-resolved measurements in water indicate a rapid swelling after immersion into the water bath. The present study paves the way for exciting porous materials based on the herein synthesized amphiphilic three-arm block copolymers useful for applications as absorber materials and coatings
Nanoparticle shape is the game-changer for blood–brain barrier crossing and delivery through tunneling nanotubes among glioblastoma cells
Full text linkTunneling nanotubes (TNTs) are thin, dynamic, long membrane protrusions that allow intercellular exchanges of signaling clues, molecules and organelles. The presence of TNTs and their involvement as drug delivery channels have been observed in several types of cancer, including glioblastoma. Recently, increased attention has been directed toward nanoparticles (NPs) that can be transported in TNTs. However, few data are available on the role of physical parameters of nanoparticles, such as size, shape, charge and flexibility, in determining their transfer efficiency between cells by TNTs. Here, we focused our attention on NP shape, manufacturing spherical, discoidal and deformable negatively charged lipid-based NPs with sizes <120 nm and similar stiffness. The TNT-mediated transfer of NPs was investigated in 2D and 3D culture models of human glioblastoma cells. The permeability and biocompatibility of the blood–brain barrier (BBB) were also assessed. Results showed that discoidal NPs displayed the highest TNT-mediated transfer efficiency between cancer cells, with a maximum velocity of 69 nm s−1, and a higher endothelial permeability (1.29 × 10−5 cm min−1) across the BBB in an in vitro model. This depends on the NP shape because discoidal NPs have a larger surface area exposed to the flow along the TNT channel. Overall, the results suggest that the shape of NPs is the game-changer for more efficient TNT-mediated transfer between cancer cells, thus introducing a sustainable solution to improve the diffusion rate at which the NPs spread in the tumour microenvironment, opening the possibility of ameliorating drug distribution to difficult-to-reach cancer cell populations
Segmented, Side-Emitting Hydrogel Optical Fibers for Multimaterial Extrusion Printing
Full text linkSide-emitting optical fibers allow light to be deliberately outcoupled along the fiber. Introducing a customized side-emission profile requires modulation of the guiding and emitting properties along the fiber length, which is a particular challenge in continuous processing of soft waveguides. In this work, it is demonstrated that multimaterial extrusion printing can generate hydrogel optical fibers with tailored segments for light-side emission. The fibers are based on diacrylated Pluronic F-127 (PluDA). 1 mm diameter fibers are printed with segments of different optical properties by switching between a PluDA waveguiding ink and a PluDA scattering ink containing nanoparticles. The method allows the fabrication of fibers with segment lengths below 500 microns in a continuous process. The length of the segments is tailored by varying the switching time between inks during printing. Fibers with customized side-emission profiles along their length are presented. The functionality of the printed fibers is demonstrated by exciting fluorescence inside a surrounding 3D hydrogel. The presented technology and material combination allow unprecedented flexibility for designing soft optical fibers with customizable optical properties using simple processes and a medical material. This approach can be of interest to improve illumination inside tissues for photodynamic therapy (PDT)
Developing an In Vitro Model of Endotoxemia to Assess the Immunomodulatory Effects of Anti-Inflammatory Peptide-Secreting Living Therapeutics
Full text linkLiving therapeutics are attractive candidates to tackle the limitations of classically delivered therapeutic peptides, which are often poorly stable and require cost-intensive modifications. Their functional assessment is limited to animal experiments, which increase the complexity to evaluate the dynamic nature of these systems. Therefore, we developed an in vitro model of endotoxemia using macrophages to assess early-stage anti-inflammatory Living therapeutics. We refined the model based on three anti-inflammatory peptides (KCF-18, I6P7, and α-MSH) and identified suitable therapeutic concentrations and treatment durations. We applied the model to Lactiplantibacillus plantarum TF103, a probiotic engineered to secrete these peptides. The model revealed that Living therapeutics enhanced the effects of the peptides, requiring lower amounts of anti-inflammatory effects. This points to potential synergistic effects between peptides and bacteria. The model presented here allows the investigation of dynamic regimes, which could be useful in the development of complex systems such as the ones encountered in Living therapeutics
Origin of Dynamic Network Formation of 2D Nanofillers in a Flexible Matrix
Full text linkThe 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
Performance of Microporous Carbon Cathodes and Impact of Cathode/Solid Electrolyte Interphase Formation Using Carbonate and Ether-Based Electrolytes in Lithium–Sulfur Batteries
Full text linkLithium–sulfur batteries (Li–S), controlled by the sulfur cathode’s conversion reaction, are a promising technology due to their high theoretical capacities and the sustainability of sulfur. In contrast to commercially available lithium-ion cathodes, the Li–S system still suffers from unstable cycling performance due to the diffusion of soluble polysulfides out of the cathode. This study explored sulfur cathodes with varying pore sizes, mainly in the micropore regime (<2 nm). We conducted the work using carbonate-based and ether-based electrolytes to investigate the impact of the cathode/solid electrolyte interphase on the cycling performance of the battery. By infiltrating the carbon with different C/S ratios, we found that the maximum sulfur infiltration attained was 61 mass % with a C/S ratio of 1:1.5. The best sulfur utilization and cycling performance were achieved with carbonate electrolyte and 50 mass % S in carbon with a specific surface area of 2210 m2/g and a total pore volume of 1.20 cm3/g. Our findings emphasize the importance of designing cathodes with optimized pore structures to balance sulfur accommodation, minimize sulfur dissolution, and mitigate capacity degradation
Competing ion effects and electrolyte optimization for electrochemical lithium extraction from spent lithium iron phosphate battery cathodes
Full text linkWith rising demand for lithium-ion batteries, efficient recycling is crucial. While conventional methods face cost and environmental challenges, electrochemical recovery offers a sustainable and energy-efficient alternative. In this study, we investigate the electrochemical recovery of lithium-ions from spent lithium iron phosphate batteries using carbon-coated lithium iron phosphate electrodes, with a focus on the influence of pH adjustment and competing ion effects. Our results demonstrate that NaOH-adjusted electrolytes provide the highest lithium-ion recovery efficiency, with an average removal capacity of 18 mgLi gLFP−1 over 50 cycles. However, prolonged cycling leads to capacity fading, particularly in the presence of competing cations such as Na+ and K+, which impact lithium selectivity and electrode stability. These findings underscore the importance of optimizing electrolyte conditions and electrode materials to enhance long-term performance. Future research should explore alternative pH control strategies and scalable process designs to facilitate industrial implementation. Advancing electrochemical lithium-ion recovery aligns with broader sustainability goals, offering a viable route toward circular battery recycling and reduced environmental impact