Albrecht Berg - Academia.edu (original) (raw)

Papers by Albrecht Berg

Bioactive Materials, 2021

Sustained inflammation associated with dysregulated macrophage activation prevents tissue formati... more Sustained inflammation associated with dysregulated macrophage activation prevents tissue formation and healing of chronic wounds. Control of inflammation and immune cell functions thus represents a promising approach in the development of advanced therapeutic strategies. Here we describe immunomodulatory hyaluronan/collagen (HA-AC/coll)-based hydrogels containing high-sulfated hyaluronan (sHA) as immunoregulatory component for the modulation of inflammatory macrophage activities in disturbed wound healing. Solute sHA downregulates inflammatory activities of bone marrow-derived and tissue-resident macrophages in vitro. This further affects macrophage-mediated pro-inflammatory activation of skin cells as shown in skin ex-vivo cultures. In a mouse model of acute skin inflammation, intradermal injection of sHA downregulates the inflammatory processes in the skin. This is associated with the promotion of an anti-inflammatory gene signature in skin macrophages indicating a shift of their activation profile. For in vivo translation, we designed HA-AC/coll hydrogels allowing delivery of sHA into wounds over a period of at least one week. Their immunoregulatory capacity was analyzed in a translational experimental approach in skin wounds of diabetic db/db mice, an established model for disturbed wound healing. The sHA-releasing hydrogels improved defective tissue repair with reduced inflammation, augmented pro-regenerative macrophage activation, increased vascularization, and accelerated new tissue formation and wound closure.

Zeitschrift für Chemie, 2010

Materials Science and Engineering: C, 2014

This study focuses on the development of novel biocompatible macroporous cryogels by electron-bea... more This study focuses on the development of novel biocompatible macroporous cryogels by electron-beam assisted free-radical crosslinking reaction of polymerizable dextran and hyaluronan derivatives. As a main advantage this straightforward approach provides highly pure materials of high porosity without using additional crosslinkers or initiators. The cryogels were characterized with regard to their morphology and their basic properties including thermal and mechanical characteristics, and swellability. It was found that the applied irradiation dose and the chemical composition strongly influence the material properties of the resulting cryogels. Preliminary cytotoxicity tests illustrate the excellent in vitro-cytocompatibility of the fabricated cryogels making them especially attractive as matrices in tissue regeneration procedures.

Journal of Natural Products, 2003

Journal of Natural Products, 2004

Chemical investigation of the sponge Leucetta chagosensis collected in Indonesia afforded five ne... more Chemical investigation of the sponge Leucetta chagosensis collected in Indonesia afforded five new imidazole alkaloids, naamine F (2), naamine G (3), kealiinine A (6), kealiinine B (7), and kealiinine C (8), in addition to the known compound naamine A (1). Naamine G (3) exhibited strong antifungal activity against the phytopathogenic fungus Cladosporium herbarum and also showed mild cytotoxicity against mouse lymphoma (L5178Y) and human cervix carcinoma (HeLa) cell lines. In the brine shrimp assay, kealiinine A (6) was more active than naamine G (3). The structures of the new compounds were unambiguously established by 1D and 2D NMR and MS data.

Peptide Science, 2011

The nonproteinogenic, Cα‐tetrasubstituted, helicogenic, chiral α‐amino acid isovaline (Iva) is re... more The nonproteinogenic, Cα‐tetrasubstituted, helicogenic, chiral α‐amino acid isovaline (Iva) is remarkably spread in the biosphere. Together with its achiral, lower homolog α‐aminoisobutyric acid (Aib), it represents a characteristic marker of a class of naturally occurring peptide antibiotics, for which the acronym “peptaibiotics” became established. In these peptides, Iva occurs as the (S)‐(= L) or the (R)‐(= D) enantiomer, but peptide sequences containing both Iva enantiomers are also common. Here, we applied our recently developed 1H‐NMR method, which enables the nondestructive assignment of the configuration of each Iva residue in a peptide of known helical screw sense, to natural and synthetic peptaibiotics. Our method proved to be generally applicable and provided evidence that, in the peptaibiotic bergofungin A, the Iva12 configuration is (R) and not (S) as reported previously. Moreover, we extended our NMR method by including a 13C‐NMR parameter. A statistical analysis of th...

Bioelectrochemistry and Bioenergetics, 1989

This book contains the following chapters: Structures, General p01~;accharide methods, Their prop... more This book contains the following chapters: Structures, General p01~;accharide methods, Their properties, Syntheses of new carbohydrate polymers, Polysaccharide analogues and conjugates, Substitution patterns of polysaccharidc derivatives, Chemical modifications, Enzymatic modifications, Alterations of polysaccharide integrity and &ctroch~mical modifications, Relationships between structure and properties, Subject index. The broadest parts of this state-of-the-art monograph are the chapters on "Chemical modifications" and "Relationships between structure and properties". Starting with natural polysaccharides such as alginates, pectins, carrageenans, agarose, cellulose, starch, etc., synthetic analogues are described, Besides modifications by reduction, oxidation, esterification, etherification, N-alkylation, deamination, halogen &on, copolymerisation., etc., physical chemical me+bods for the determination of structures (e.g. NMR, ESR, MS, fluor&cence spectroscopy) and substitutions as well as for depolymerisation (shear degradation, ultrasonic and radical-mediated destruction) and thermochemical and electrochemical modifications are discussed in detail. As regards important relationships, the following changes of the primary and secondary structure are taken into account: hydrogen bonding, gel-forming tendency, solvent influence, interactions with salts, surfactants, proteins, etc. Each chapter is followed by a comprehensive list of references extending up to 1987) increasing the usefulness of this book as a information for everybody interested in polysaccharides.

Bioelectrochemistry and Bioenergetics, 1996

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