Brüggemann, Dorothea
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Item-typ:Veröffentlichung, The Future of Bioinspired Innovation: Exploring the Potential of NanobiomimeticsWissenschaftlicher ArtikelBand:24Heft:3897 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Self-Assembled Fibrinogen Scaffolds Support Cocultivation of Human Dermal Fibroblasts and HaCaT Keratinocytes(American Chemical Society, 2023-03-07); ; Self-assembled fibrinogen scaffolds are highly attractive biomaterials to mimic native blood clots. To explore their potential for wound healing, we studied the interaction of cocultures of human dermal fibroblasts (HDFs) and HaCaT keratinocytes with nanofibrous, planar, and physisorbed fibrinogen. Cell viability analysis indicated that the growth of HDFs and HaCaTs was supported by all fibrinogen topographies until 14 days, either in mono- or coculture. Using scanning electron microscopy and cytoskeletal staining, we observed that the native morphology of both cell types was preserved on all topographies. Expression of the marker proteins vimentin and cytokeratin-14 showed that the native phenotype of fibroblasts and undifferentiated keratinocytes, respectively, was maintained. HDFs displayed their characteristic wound healing phenotype, characterized by expression of fibronectin. Finally, to mimic the multilayered microenvironment of skin, we established successive cocultures of both cells, for which we found consistently high metabolic activities. SEM analysis revealed that HaCaTs arranged into a confluent top layer after 14 days, while fluorescent labeling confirmed the presence of both cells in the layered structure after 6 days. In conclusion, all fibrinogen topographies successfully supported the cocultivation of fibroblasts and keratinocytes, with fibrinogen nanofibers being particularly attractive for skin regeneration due to their biomimetic porous architecture and the technical possibility to be detached from an underlying substrate.Wissenschaftlicher ArtikelBand:8Heft:9103 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Effect of interface-active proteins on the salt crystal size in waterborne hybrid materials(SpringerOpen, 2021); ; ; ; Aqueous processes yielding hybrid or composite materials are widespread in natural environments and their control is fundamental for a multiplicity of living organisms. Their design and in vitro engineering require knowledge about the spatiotemporal evolution of the interactions between the involved liquid and solid phases and, especially, the interphases governing the development of adhesion during solidification. The present study illustrates the effects of distinct proteins on the precipitation of sodium chloride encompassing the size, shape and distribution of halite crystals formed during the drying of droplets containing equally concentrated saline protein solutions. The precipitates obtained from aqueous sodium chloride formulations buffered with tris(hydroxymethyl)aminomethane (Tris) contained either bovine serum albumin (BSA), fibrinogen or collagen and were characterized with respect to their structure and composition using optical and electron microscopy as well as x-ray analysis. The acquired findings highlight that depending on the protein type present during droplet drying the halite deposits predominantly exhibit cubic or polycrystalline dendritic structures. Based on the phenomenological findings, it is suggested that the formation of the interphase between the growing salt phase and the highly viscous saline aqueous jelly phase containing protein governs not only the material transport in the liquid but also the material exchange between the solid and liquid phases.Wissenschaftlicher ArtikelBand:9Heft:7112 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Organic Electrochemical Transistors and Foreign Body Reaction: First Steps Toward Long-Term Implantable Biosensing(Wiley, 2026-03); 43 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Structure, Properties and Degradation of Self-Assembled Fibrinogen Nanofiber Scaffolds(American chemical society, 2024-09-16); ; ; ; Self-assembled fibrinogen nanofibers are promising candidates for skin tissue engineering due to their biocompatibility and ability to mimic the native blood clot architecture. Here, we studied the structure-property relationship and degradation of rehydrated fibrinogen nanofibers prepared by salt-induced self-assembly, focusing on the effect of scaffold layering, cross-linking time and freeze-drying. Optimal fiber stability was achieved with cross-linking by formaldehyde (FA) vapor, while treatment with liquid aldehydes, genipin, EDC, and transglutaminase failed to preserve the nanofibrous architecture upon rehydration. Scaffold layering did not significantly influence the mechanical properties but changed the scaffold architecture, with bulk fiber scaffolds being more compact than layered scaffolds. Freeze-drying maintained the mechanical properties and interconnected pore network with average pore diameters around 20 μm, which will enhance the storage stability of self-assembled fibrinogen scaffolds. Varying cross-linking times altered the scaffold mechanics without affecting the swelling behavior, indicating that scaffold hydration can be controlled independently of the mechanical characteristics. Cross-linking times of 240 min increased scaffold stiffness and decreased elongation, while 30 min resulted in mechanical properties similar to native skin. Cross-linking for 120 min was found to reduce scaffold degradation by various enzymes in comparison to 60 min. Overall, after 35 days of incubation, plasmin and a combination of urokinase and plasminogen exhibited the strongest degradative effect, with nanofibers being more susceptible to enzymatic degradation than planar fibrinogen due to their higher specific surface area. Based on these results, self-assembled fibrinogen fiber scaffolds show great potential for future applications in soft tissue engineering that require controlled structure-function relationships and degradation characteristics.Wissenschaftlicher ArtikelBand:7Heft:987 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Biomimetic Fibrinogen Nanofiber Scaffolds for Vascular Hematopoietic Stem Cell Niche Engineering.(Wiley-VCH, 2025-10); ; Lee-Thedieck, CorneliaHematopoietic stem cells (HSCs) can reconstitute the human blood system. In vivo, HSCs are localized in and regulated by distinct bone marrow (BM) microenvironments, or niches, like the vascular HSC niches near fenestrated sinusoidal blood vessels. These delicate structures, comprising a single-layered endothelium and a discontinuous basement membrane, pose challenges in soft tissue engineering. In this study, the basement membrane in vascular niches is mimicked using nanofibrous fibrinogen scaffolds. A novel clamping system enables handling the scaffold as a membrane and seeding both sides-one with microvascular endothelial cells (HMEC-1) and the other with mesenchymal stem and stroma cells (iMSC#3). Subsequently, HSCs and their progenitors (HSPCs) are introduced from both sides to emulate their niche dynamics (residency, exit, and homing). The study reveals that the fibrinogen scaffolds are highly cytocompatible and show good cell-adhesive properties. In addition, HSPCs are able to migrate through the scaffolds, validating them as fenestrated basement membrane mimetics. This in vitro model offers insights into HSPC behavior in the vascular niche and can serve as a drug testing platform in future studies. Moreover, beyond HSCs, the presented scaffold-based mimetic of the basement membrane offers new opportunities for mimicking and studying vasculature in tissue engineering approaches.Wissenschaftlicher Artikel37 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Assembly of Rolled-Up Collagen Constructs on Porous Alumina Textiles(American chemical society, 2023-08-16); ; ; Developing new techniques to prepare free-standing tubular scaffolds has always been a challenge in the field of regenerative medicine. Here, we report a new and simple way to prepare free-standing collagen constructs with rolled-up architecture by self-assembling nanofibers on porous alumina (Al2O3) textiles modified with different silanes, carbon or gold. Following self-assembly and cross-linking with glutaraldehyde, collagen nanofibers spontaneously rolled up on the modified Al2O3 textiles and detached. The resulting collagen constructs had an inner diameter of approximately 2 to 4 mm in a rolled-up state and could be easily detached from the underlying textiles. Mechanical testing of wet collagen scaffolds following detachment yielded mean values of 3.5 ± 1.9 MPa for the tensile strength, 41.0 ± 20.8 MPa for the Young's modulus and 8.1 ± 3.7% for the elongation at break. No roll-up was observed on Al2O3 textiles without any modification, where collagen did not assemble into fibers, either. Blends of collagen and chitosan were also found to roll into fibrous constructs on silanized Al2O3 textiles, while fibrinogen nanofibers or blends of collagen and elastin did not yield such structures. Based on these differences, we hypothesize that textile surface charge and protein charge, in combination with the porous architecture of protein nanofibers and differences in mechanical strain, are key factors in inducing a scaffold roll-up. Further studies are required to develop the observed roll-up effect into a reproducible biofabrication process that can enable the controlled production of free-standing collagen-based tubes for soft tissue engineering.Wissenschaftlicher ArtikelBand:3Heft:4110 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Spatial patterning of nanofibrous collagen scaffolds modulates fibroblast morphology(IOP Publishing, 2021); ; ; ; Current knowledge about cell-biomaterial interactions is often based on two-dimensional (2D) cell culture systems like protein-coated glass slides. However, such smooth surfaces cannot mimic the nanofibrous environment of the native extracellular matrix (ECM). It is therefore a major challenge to transfer the results from 2D surfaces to 3D protein scaffolds with biomimetic nanofiber architecture. To understand the influence of different protein topographies on the cell response we introduce a new process to fabricate binary collagen scaffolds of variable thickness with spatially controlled regions of nanofibrous and smooth topography. We used pH-induced self-assembly to prepare collagen nanofibers with diameters between 130 and 150 nm on glass surfaces, which were partly covered with a polymer mask. After cross-linking with glutaraldehyde, smooth collagen films were prepared on the remaining glass regions. Atomic force microscopy revealed a much lower surface roughness of smooth collagen compared to nanofibers. Subsequently, we studied the viability, morphology and migration of 3T3 fibroblasts on both collagen topographies. We found small, elongated fibroblasts with few, long filopodia on collagen nanofibers whereas large, flat fibroblasts with many short filopodia were observed on smooth collagen. Actin stress fibers on collagen nanofibers were substantially reduced in comparison to smooth collagen. Live cell tracking revealed that fibroblasts on thin nanofibrous collagen migrated faster than on smooth collagen. In summary, binary collagen scaffolds enabled us for the first time to study cell responses to topographical cues on a single protein scaffold. In future, it will be intriguing to transfer our patterning process to other proteins to study fundamental principles of topography-dependent cell recognition processes.Wissenschaftlicher ArtikelBand:1360 60 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Influence of Divalent Metal Ions on the Precipitation of the Plasma Protein Fibrinogen(American Chemical Society, 2021-10-20); ; ; ; Fibrinogen nanofibers are very attractive biomaterials to mimic the native blood clot architecture. Previously, we reported the self-assembly of fibrinogen nanofibers in the presence of monovalent salts and have now studied how divalent salts influence fibrinogen precipitation. Although the secondary fibrinogen structure was significantly altered with divalent metal ions, morphological analysis revealed exclusively smooth fibrinogen precipitates. In situ monitoring of the surface roughness facilitated predicting the tendency of various salts to form fibrinogen fibers or smooth films. Analysis of the chemical composition revealed that divalent salts were removed from smooth fibrinogen films upon rinsing while monovalent Na+ species were still present in fibrinogen fibers. Therefore, we assume that the decisive factor controlling the morphology of fibrinogen precipitates is direct ion–protein contact, which requires disruption of the ion-surrounding hydration shells. We conclude that in fibrinogen aggregates, this mechanism is effective only for monovalent ions, whereas divalent ions are limited to indirect fibrinogen adsorption.Wissenschaftlicher ArtikelBand:22Heft:1130 23 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Self-assembled fibrinogen nanofibers support fibroblast adhesion and prevent E. coli infiltration(Elsevier Science, 2021-07); ; ; ; Fibrinogen nanofibers hold great potential for wound healing applications since they mimic the native blood clot architecture and offer important binding sites to support fibroblast adhesion and migration. Recently, we introduced a new method of saltinduced self-assembly to prepare nanofibrous fibrinogen scaffolds. Here, we present our results on the mechanical properties of these scaffolds and their interaction with 3T3 fibroblasts and E. coli bacteria, which we used as model systems for wound healing. Hydrated, nanofibrous fibrinogen scaffolds showed a Young's modulus of 1.3 MPa, which is close to the range of native fibrin. 3T3 fibroblasts adhered and proliferated well on nanofibrous and planar fibrinogen up to 72 h with a less pronounced actin cytoskeleton on nanofibers in comparison to planar fibrinogen. Fibroblasts on nanofibers were smaller with many short filopodia while larger cells with few long filopodia were found on planar fibrinogen. Live cell tracking revealed higher migration velocities on nanofibers in comparison to planar fibrinogen. The growth of E. coli bacteria on nanofibrous fibrinogen was significantly reduced as compared to agar controls with no bacteria migrating through the nanofibers. In summary, we conclude that self-assembled fibrinogen nanofibers could become highly attractive as future scaffolds for wound healing applications.Wissenschaftlicher ArtikelHeft:126356