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End date: 2023 × Start date: 2021 × End date: 2023 × Start date: 2020 × DDC: 540 × DDC: 610 × Type: Article × WGL Institute: IPF ×

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Now showing 1 - 5 of 5
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    Poly(2-alkyl-2-oxazoline)-Heparin Hydrogels—Expanding the Physicochemical Parameter Space of Biohybrid Materials
    (Weinheim : Wiley-VCH, 2021) Hahn, Dominik; Sonntag, Jannick M.; Lück, Steffen; Maitz, Manfred F.; Freudenberg, Uwe; Jordan, Rainer; Werner, Carsten
    Poly(ethylene glycol) (PEG)-glycosaminoglycan (GAG) hydrogel networks are established as very versatile biomaterials. Herein, the synthetic gel component of the biohybrid materials is systematically varied by combining different poly(2-alkyl-2-oxazolines) (POx) with heparin applying a Michael-type addition crosslinking scheme: POx of gradated hydrophilicity and temperature-responsiveness provides polymer networks of distinctly different stiffness and swelling. Adjusting the mechanical properties and the GAG concentration of the gels to similar values allows for modulating the release of GAG-binding growth factors (VEGF165 and PDGF-BB) by the choice of the POx and its temperature-dependent conformation. Adsorption of fibronectin, growth of fibroblasts, and bacterial adhesion scale with the hydrophobicity of the gel-incorporated POx. In vitro hemocompatibility tests with freshly drawn human whole blood show advantages of POx-based gels compared to the PEG-based reference materials. Biohybrid POx hydrogels can therefore enable biomedical technologies requiring GAG-based materials with customized and switchable physicochemical characteristics. © 2021 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.
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    Electrochemical approach for isolation of chitin from the skeleton of the black coral cirrhipathes sp. (Antipatharia)
    (Basel : MDPI, 2020) Nowacki, Krzysztof; Stępniak, Izabela; Langer, Enrico; Tsurkan, Mikhail; Wysokowski, Marcin; Petrenko, Iaroslav; Khrunyk, Yuliya; Fursov, Andriy; Bo, Marzia; Bavestrello, Giorgio; Joseph, Yvonne; Ehrlich, Hermann
    The development of novel and effective methods for the isolation of chitin, which remains one of the fundamental aminopolysaccharides within skeletal structures of diverse marine invertebrates, is still relevant. In contrast to numerous studies on chitin extraction from crustaceans, mollusks and sponges, there are only a few reports concerning its isolation from corals, and especially black corals (Antipatharia). In this work, we report the stepwise isolation and identification of chitin from Cirrhipathes sp. (Antipatharia, Antipathidae) for the first time. The proposed method, aiming at the extraction of the chitinous scaffold from the skeleton of black coral species, combined a well-known chemical treatment with in situ electrolysis, using a concentrated Na2SO4 aqueous solution as the electrolyte. This novel method allows the isolation of a-chitin in the form of a microporous membrane-like material. Moreover, the extracted chitinous scaffold, with a well-preserved, unique pore distribution, has been extracted in an astoundingly short time (12 h) compared to the earlier reported attempts at chitin isolation from Antipatharia corals. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
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    A Complementary and Revised View on the N-Acylation of Chitosan with Hexanoyl Chloride
    (Basel : MDPI, 2021) Reis, Berthold; Gerlach, Niklas; Steinbach, Christine; Haro Carrasco, Karina; Oelmann, Marina; Schwarz, Simona; Müller, Martin; Schwarz, Dana
    The modification of the biobased polymer chitosan is a broad and widely studied field. Herein, an insight into the hydrophobization of low-molecular-weight chitosan by substitution of amino functionalities with hexanoyl chloride is reported. Thereby, the influence of the pH of the reaction media was investigated. Further, methods for the determination of the degree of substitution based on 1H-NMR, FTIR, and potentiometric titration were compared and discussed regarding their accuracy and precision. 1H-NMR was the most accurate method, while FTIR and the potentiometric titration, though precise and reproducible, underlie the influence of complete protonation and solubility issues. Additionally, the impact of the pH variation during the synthesis on the properties of the samples was investigated by Cd2+ sorption experiments. The adjusted pH values during the synthesis and, therefore, the obtained degrees of substitution possessed a strong impact on the adsorption properties of the final material.
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    Matrix metalloproteinase-1 decorated polymersomes, a surface-active extracellular matrix therapeutic, potentiates collagen degradation and attenuates early liver fibrosis
    (New York, NY [u.a.] : Elsevier, 2021) Geervliet, Eline; Moreno, Silvia; Baiamonte, Luca; Booijink, Richell; Boye, Susanne; Wang, Peng; Voit, Brigitte; Lederer, Albena; Appelhans, Dietmar; Bansal, Ruchi
    Liver fibrosis affects millions of people worldwide and is rising vastly over the past decades. With no viable therapies available, liver transplantation is the only curative treatment for advanced diseased patients. Excessive accumulation of aberrant extracellular matrix (ECM) proteins, mostly collagens, produced by activated hepatic stellate cells (HSCs), is a hallmark of liver fibrosis. Several studies have suggested an inverse correlation between collagen-I degrading matrix metalloproteinase-1 (MMP-1) serum levels and liver fibrosis progression highlighting reduced MMP-1 levels are associated with poor disease prognosis in patients with liver fibrosis. We hypothesized that delivery of MMP-1 might potentiate collagen degradation and attenuate fibrosis development. In this study, we report a novel approach for the delivery of MMP-1 using MMP-1 decorated polymersomes (MMPsomes), as a surface-active vesicle-based ECM therapeutic, for the treatment of liver fibrosis. The storage-stable and enzymatically active MMPsomes were fabricated by a post-loading of Psomes with MMP-1. MMPsomes were extensively characterized for the physicochemical properties, MMP-1 surface localization, stability, enzymatic activity, and biological effects. Dose-dependent effects of MMP-1, and effects of MMPsomes versus MMP-1, empty polymersomes (Psomes) and MMP-1 + Psomes on gene and protein expression of collagen-I, MMP-1/TIMP-1 ratio, migration and cell viability were examined in TGFβ-activated human HSCs. Finally, the therapeutic effects of MMPsomes, compared to MMP-1, were evaluated in vivo in carbon-tetrachloride (CCl4)-induced early liver fibrosis mouse model. MMPsomes exhibited favorable physicochemical properties, MMP-1 surface localization and improved therapeutic efficacy in TGFβ-activated human HSCs in vitro. In CCl4-induced early liver fibrosis mouse model, MMPsomes inhibited intra-hepatic collagen-I (ECM marker, indicating early liver fibrosis) and F4/80 (marker for macrophages, indicating liver inflammation) expression. In conclusion, our results demonstrate an innovative approach of MMP-1 delivery, using surface-decorated MMPsomes, for alleviating liver fibrosis.
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    Ultrathin 2D Titanium Carbide MXene (Ti3C2Tx) Nanoflakes Activate WNT/HIF-1α-Mediated Metabolism Reprogramming for Periodontal Regeneration
    (Weinheim : Wiley-VCH, 2021) Cui, Di; Kong, Na; Ding, Liang; Guo, Yachong; Yang, Wenrong; Yan, Fuhua
    Periodontal defect regeneration in severe periodontitis relies on the differentiation and proliferation of periodontal ligament cells (PDLCs). Recently, an emerging 2D nanomaterial, MXene (Ti3C2Tx), has gained more and more attention due to the extensive antibacterial and anticancer activity, while its potential biomedical application on tissue regeneration remains unclear. Through a combination of experimental and multiscale simulation schemes, Ti3C2Tx has exhibited satisfactory biocompatibility and induced distinguish osteogenic differentiation of human PDLCs (hPDLCs), with upregulated osteogenesis-related genes. Ti3C2Tx manages to activate the Wnt/β-catenin signaling pathway by enhancing the Wnt-Frizzled complex binding, thus stabilizing HIF-1α and altering metabolic reprogramming into glycolysis. In vivo, hPDLCs pretreated by Ti3C2Tx display excellent performance in new bone formation and osteoclast inhibition with enhanced RUNX2, HIF-1α, and β-catenin in an experimental rat model of periodontal fenestration defects, indicating that this material has high efficiency of periodontal regeneration promotion. It is demonstrated in this work that Ti3C2Tx has highly efficient therapeutic effects in osteogenic differentiation and periodontal defect repairment. © 2021 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH