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    Anti-Stokes Stress Sensing: Mechanochemical Activation of Triplet-Triplet Annihilation Photon Upconversion
    (Weinheim : Wiley-VCH, 2019) Yildiz, Deniz; Baumann, Christoph; Mikosch, Annabel; Kuehne, Alexander J.C.; Herrmann, Andreas; Göstl, Robert
    The development of methods to detect damage in macromolecular materials is of paramount importance to understand their mechanical failure and the structure–property relationships of polymers. Mechanofluorophores are useful and sensitive molecular motifs for this purpose. However, to date, tailoring of their optical properties remains challenging and correlating emission intensity to force induced material damage and the respective events on the molecular level is complicated by intrinsic limitations of fluorescence and its detection techniques. Now, this is tackled by developing the first stress-sensing motif that relies on photon upconversion. By combining the Diels–Alder adduct of a π-extended anthracene with the porphyrin-based triplet sensitizer PtOEP in polymers, triplet–triplet annihilation photon upconversion of green to blue light is mechanochemically activated in solution as well as in the solid state. © 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
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    DNA Nanotechnology Enters Cell Membranes
    (Weinheim : Wiley-VCH, 2019) Huo, Shuaidong; Li, Hongyan; Boersma, Arnold J.; Herrmann, Andreas
    DNA is more than a carrier of genetic information: It is a highly versatile structural motif for the assembly of nanostructures, giving rise to a wide range of functionalities. In this regard, the structure programmability is the main advantage of DNA over peptides, proteins, and small molecules. DNA amphiphiles, in which DNA is covalently bound to synthetic hydrophobic moieties, allow interactions of DNA nanostructures with artificial lipid bilayers and cell membranes. These structures have seen rapid growth with great potential for medical applications. In this Review, the current state of the art of the synthesis of DNA amphiphiles and their assembly into nanostructures are first summarized. Next, an overview on the interaction of these DNA amphiphiles with membranes is provided, detailing on the driving forces and the stability of the interaction. Moreover, the interaction with cell surfaces in respect to therapeutics, biological sensing, and cell membrane engineering is highlighted. Finally, the challenges and an outlook on this promising class of DNA hybrid materials are discussed.
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    Significant Upregulation of Alzheimer's β-Amyloid Levels in a Living System Induced by Extracellular Elastin Polypeptides
    (Weinheim : Wiley-VCH, 2019) Ma, Chao; Su, Juanjuan; Sun, Yao; Feng, Yang; Shen, Nolan; Li, Bo; Liang, Yingxia; Yang, Xintong; Wu, Hui; Zhang, Hongjie; Herrmann, Andreas; Tanzi, Rudolph E.; Liu, Kai; Zhang, Can
    Alzheimer's disease (AD) is a neurodegenerative disorder and the primary cause of age-related dementia. The etiology of AD is complex and has not been completely elucidated. Herein, we report that treatment with elastin-like polypeptides (ELPs), a component of the brain extracellular matrix (ECM), significantly increased the levels of AD-related amyloid-β peptides (Aβ) both in vitro and in vivo. Regarding the molecular mechanism(s), the upregulation of Aβ levels was related to increased proteolytic processing of the amyloid precursor protein. Furthermore, nesting tests demonstrated that the ELP-treated animals showed significant neurobehavioral deficits with cognitive impairment. These results suggest that the elastin is associated with AD-related pathological and behavioral changes. This finding presents a new aspect for Alzheimer's amyloidosis event and provides a great promise in developing ELP-based model systems to better understand the pathogenesis of AD. © 2019