Search

Your search keyword '"Freudenberg, Uwe"' showing total 216 results
Start Over Author "Freudenberg, Uwe" Language english
216 results on '"Freudenberg, Uwe"'

2. Nerve growth factor receptor (Ngfr) induces neurogenic plasticity by suppressing reactive astroglial Lcn2/Slc22a17 signaling in Alzheimer’s disease

Author

Siddiqui, Tohid, Cosacak, Mehmet Ilyas, Popova, Stanislava, Bhattarai, Prabesh, Yilmaz, Elanur, Lee, Annie J., Min, Yuhao, Wang, Xue, Allen, Mariet, İş, Özkan, Atasavum, Zeynep Tansu, Rodriguez-Muela, Natalia, Vardarajan, Badri N., Flaherty, Delaney, Teich, Andrew F., Santa-Maria, Ismael, Freudenberg, Uwe, Werner, Carsten, Tosto, Giuseppe, Mayeux, Richard, Ertekin-Taner, Nilüfer, and Kizil, Caghan

Published
2023
Full Text
View/download PDF

7. The Influence of Sulfation Degree of Glycosaminoglycan-Functionalized 3D Collagen I Networks on Cytokine Profiles of In Vitro Macrophage–Fibroblast Cocultures.

Author

Ullm, Franziska, Renner, Alexander, Freudenberg, Uwe, Werner, Carsten, and Pompe, Tilo

Subjects
SULFATION, GLYCOSAMINOGLYCANS, COLLAGEN, MACROPHAGES, FIBROBLASTS
Abstract

Cell–cell interactions between fibroblasts and immune cells, like macrophages, are influenced by interaction with the surrounding extracellular matrix during wound healing. In vitro hydrogel models that mimic and modulate these interactions, especially of soluble mediators like cytokines, may allow for a more detailed investigation of immunomodulatory processes. In the present study, a biomimetic extracellular matrix model based on fibrillar 3D collagen I networks with a functionalization with heparin or 6-ON-desulfated heparin, as mimics of naturally occurring heparan sulfate, was developed to modulate cytokine binding effects with the hydrogel matrix. The constitution and microstructure of the collagen I network were found to be stable throughout the 7-day culture period. A coculture study of primary human fibroblasts/myofibroblasts and M-CSF-stimulated macrophages was used to show its applicability to simulate processes of progressed wound healing. The quantification of secreted cytokines (IL-8, IL-10, IL-6, FGF-2) in the cell culture supernatant demonstrated the differential impact of glycosaminoglycan functionalization of the collagen I network. Most prominently, IL-6 and FGF-2 were shown to be regulated by the cell culture condition and network constitution, indicating changes in paracrine and autocrine cell–cell communication of the fibroblast–macrophage coculture. From this perspective, we consider our newly established in vitro hydrogel model suitable for mechanistic coculture analyses of primary human cells to unravel the role of extracellular matrix factors in key events of tissue regeneration and beyond. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

9. 3D Culture Method for Alzheimer's Disease Modeling Reveals Interleukin-4 Rescues Aβ42-Induced Loss of Human Neural Stem Cell Plasticity

Author

Papadimitriou, Christos, Celikkaya, Hilal, Cosacak, Mehmet I., Mashkaryan, Violeta, Bray, Laura, Bhattarai, Prabesh, Brandt, Kerstin, Hollak, Heike, Chen, Xin, He, Shuijin, Antos, Christopher L., Lin, Weilin, Thomas, Alvin Kuriakose, Dahl, Andreas, Kurth, Thomas, Friedrichs, Jens, Zhang, Yixin, Freudenberg, Uwe, Werner, Carsten, and Kizil, Caghan

Published
2018
Full Text
View/download PDF

22. Sustained Release of Human Adipose Tissue Stem Cell Secretome from Star‐Shaped Poly(ethylene glycol) Glycosaminoglycan Hydrogels Promotes Motor Improvements after Complete Transection in Spinal Cord Injury Rat Model.

Author

Silva, Deolinda, Schirmer, Lucas, Pinho, Tiffany S., Atallah, Passant, Cibrão, Jorge R., Lima, Rui, Afonso, João, B‐Antunes, Sandra, Marques, Cláudia R., Dourado, João, Freudenberg, Uwe, Sousa, Rui A., Werner, Carsten, and Salgado, António J.

Published
2023
Full Text
View/download PDF

24. Discriminant Principal Component Analysis of ToF‐SIMS Spectra for Deciphering Compositional Differences of MSC‐Secreted Extracellular Matrices.

Author

Zimmermann, Ralf, Nitschke, Mirko, Magno, Valentina, Freudenberg, Uwe, Sockel, Katja, Stölzel, Friedrich, Wobus, Manja, Platzbecker, Uwe, and Werner, Carsten

Subjects
PRINCIPAL components analysis, SECONDARY ion mass spectrometry, EXTRACELLULAR matrix, SPECTRUM analysis, MYELODYSPLASTIC syndromes
Abstract

Identifying characteristic extracellular matrix (ECM) variants is a key challenge in mechanistic biology, bioengineering, and medical diagnostics. The reported study demonstrates the potential of time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) to detect subtle differences between human mesenchymal stromal cell (MSC)‐secreted ECM types as induced by exogenous stimulation or emerging pathology. ToF‐SIMS spectra of decellularized ECM samples are evaluated by discriminant principal component analysis (DPCA), an advanced multivariate analysis technique, to decipher characteristic compositional features. To establish the approach, signatures of major ECM proteins are determined from samples of pre‐defined mixtures. Based on that, sets of ECM variants produced by MSCs in vitro are analyzed. Differences in the content of collagen, fibronectin, and laminin in the ECM resulting from the combined supplementation of MSC cultures with polymers that induce macromolecular crowding and with ascorbic acid are detected from the DPCA of ToF‐SIMS spectra. The results are verified by immunostaining. Finally, the comparative ToF‐SIMS analysis of ECM produced by MSCs of healthy donors and patients suffering from myelodysplastic syndrome display the potential of the novel methodology to reveal disease‐associated alterations of the ECM composition. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

41. Tuning the network charge of biohybrid hydrogel matrices to modulate the release of SDF-1.

Author

Kühn, Sebastian, Freyse, Joanna, Atallah, Passant, Rademann, Jörg, Freudenberg, Uwe, and Werner, Carsten

Subjects
HYDROGELS, POLYMER networks, SACCHARIDES, CELL migration, GLYCOSAMINOGLYCANS, HEPARIN, POLYMERS, STROMAL cell-derived factor 1
Abstract

The delivery of chemotactic signaling molecules via customized biomaterials can effectively guide the migration of cells to improve the regeneration of damaged or diseased tissues. Here, we present a novel biohybrid hydrogel system containing two different sulfated glycosaminoglycans (sGAG)/sGAG derivatives, namely either a mixture of short heparin polymers (Hep-Mal) or structurally defined nona-sulfated tetrahyaluronans (9s-HA4-SH), to precisely control the release of charged signaling molecules. The polymer networks are described in terms of their negative charge, i.e. the anionic sulfate groups on the saccharides, using two parameters, the integral density of negative charge and the local charge distribution (clustering) within the network. The modulation of both parameters was shown to govern the release characteristics of the chemotactic signaling molecule SDF-1 and allows for seamless transitions between burst and sustained release conditions as well as the precise control over the total amount of delivered protein. The obtained hydrogels with well-adjusted release profiles effectively promote MSC migration in vitro and emerge as promising candidates for new treatment modalities in the context of bone repair and wound healing. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

42. Chemokine‐Capturing Wound Contact Layer Rescues Dermal Healing.

Author

Schirmer, Lucas, Atallah, Passant, Freudenberg, Uwe, and Werner, Carsten

Subjects
CHRONIC wounds & injuries, GRANULATION tissue, GROWTH factors, ETHYLENE glycol, CONNECTIVE tissues, CHEMOKINES, WOUND healing, HEALING
Abstract

Excessive inflammation often impedes the healing of chronic wounds. Scavenging of chemokines by multiarmed poly(ethylene glycol)‐glycosaminoglycan (starPEG‐GAG) hydrogels has recently been shown to support regeneration in a diabetic mouse chronic skin wound model. Herein, a textile‐starPEG‐GAG composite wound contact layer (WCL) capable of selectively sequestering pro‐inflammatory chemokines is reported. Systematic variation of the local and integral charge densities of the starPEG‐GAG hydrogel component allows for tailoring its affinity profile for biomolecular signals of the wound milieu. The composite WCL is subsequently tested in a large animal (porcine) model of human wound healing disorders. Dampening excessive inflammatory signals without affecting the levels of pro‐regenerative growth factors, the starPEG‐GAG hydrogel‐based WCL treatment induced healing with increased granulation tissue formation, angiogenesis, and deposition of connective tissue (collagen fibers). Thus, this biomaterials technology expands the scope of a new anti‐inflammatory therapy toward clinical use. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

45. Tuning the Local Availability of VEGF within Glycosaminoglycan‐Based Hydrogels to Modulate Vascular Endothelial Cell Morphogenesis.

Author

Limasale, Yanuar Dwi Putra, Atallah, Passant, Werner, Carsten, Freudenberg, Uwe, and Zimmermann, Ralf

Subjects
GLYCOSAMINOGLYCANS, VASCULAR endothelial cells, VASCULAR endothelial growth factors, HYDROGELS, POLYMER networks, GROWTH factors, MORPHOGENESIS
Abstract

Incorporation of sulfated glycosaminoglycans (GAGs) into cell‐instructive polymer networks is shown to be instrumental in controlling the diffusivity and activity of growth factors. However, a subtle balance between local retention and release of the factors is needed to effectively direct cell fate decisions. To quantitatively unravel material characteristics governing these key features, the GAG content and the GAG sulfation pattern of star‐shaped poly(ethylene glycol) (starPEG)–GAG hydrogels are herein tuned to control the local availability and bioactivity of GAG‐affine vascular endothelial growth factor (VEGF165). Hydrogels containing varying concentrations of heparin or heparin derivatives with different sulfation pattern are prepared and thoroughly characterized for swelling, mechanical properties, and growth factor transport. Mathematical models are developed to predict the local concentration and spatial distribution of free and bound VEGF165 within the gel matrices. The results of simulation and experimental studies concordantly reveal how the GAG concentration and sulfation pattern determine the local availability of VEGF165 within the cell‐instructive hydrogels and how the factor—in interplay with cell‐instructive gel properties—determines the formation and spatial organization of capillary networks of embedded human vascular endothelial cells. Taken together, this study exemplifies how mathematical modeling and rational hydrogel design can be combined to pave the way for precision tissue engineering. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results