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- ItemElectrochemical 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, HermannThe 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/).
- ItemIncreased biocompatibility and bioactivity after energetic PVD surface treatments(Basel : MDPI, 2009) Mändl, S.Ion implantation, a common technology in semiconductor processing, has been applied to biomaterials since the 1960s. Using energetic ion bombardment, a general term which includes conventional ion implantation plasma immersion ion implantation (PIII) and ion beam assisted thin film deposition, functionalization of surfaces is possible. By varying and adjusting the process parameters, several surface properties can be attuned simultaneously. Extensive research details improvements in the biocompatibility, mainly by reducing corrosion rates and increasing wear resistance after surface modification. Recently, enhanced bioactivity strongly correlated with the surface topography and less with the surface chemistry has been reported, with an increased roughness on the nanometer scale induced by self-organisation processes during ion bombardment leading to faster cellular adhesion processes. © 2009 by the authors;.
- ItemNew Source of 3D Chitin Scaffolds: The Red Sea Demosponge Pseudoceratina arabica (Pseudoceratinidae, Verongiida)(Basel : MDPI, 2019) Shaala, Lamiaa A.; Asfour, Hani Z.; Youssef, Diaa T.A.; Żółtowska-Aksamitowska, Sonia; Wysokowski, Marcin; Tsurkan, Mikhail; Galli, Roberta; Meissner, Heike; Petrenko, Iaroslav; Tabachnick, Konstantin; Ivanenko, Viatcheslav N.; Bechmann, Nicole; Muzychka, Lyubov V.; Smolii, Oleg B.; Martinović, Rajko; Joseph, Yvonne; Jesionowski, Teofil; Ehrlich, HermannThe bioactive bromotyrosine-derived alkaloids and unique morphologically-defined fibrous skeleton of chitin origin have been found recently in marine demosponges of the order Verongiida. The sophisticated three-dimensional (3D) structure of skeletal chitinous scaffolds supported their use in biomedicine, tissue engineering as well as in diverse modern technologies. The goal of this study was the screening of new species of the order Verongiida to find another renewable source of naturally prefabricated 3D chitinous scaffolds. Special attention was paid to demosponge species, which could be farmed on large scale using marine aquaculture methods. In this study, the demosponge Pseudoceratina arabica collected in the coastal waters of the Egyptian Red Sea was examined as a potential source of chitin for the first time. Various bioanalytical tools including scanning electron microscopy (SEM), fluorescence microscopy, FTIR analysis, Calcofluor white staining, electrospray ionization mass spectrometry (ESI-MS), as well as a chitinase digestion assay were successfully used to confirm the discovery of a-chitin within the skeleton of P. arabica. The current finding should make an important contribution to the field of application of this verongiid sponge as a novel renewable source of biologically-active metabolites and chitin, which are important for development of the blue biotechnology especially in marine oriented biomedicine. © 2019 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/).
- ItemBiological materials - bioinspiration on different length scales(Saarbrücken : Leibniz-Institut für Neue Materialien, 2011) Weiss, IngridThis article investigates nacre and peacock feather rachis from a molecular and structural point of view, in addition to unifying principles in nature that may control hierarchical functions. This biological material serves as an example for deciphering basic principles in nature that may subsequently be used to design new artificial materials and structures.
- ItemUnravelling New Processes at Interfaces: Photochemical Isoprene Production at the Sea Surface(Columbus, Ohio : American Chemical Society, 2015) Ciuraru, Raluca; Fine, Ludovic; van Pinxteren, Manuela; D’Anna, Barbara; Herrmann, Hartmut; George, ChristianIsoprene is an important reactive gas that is produced mainly in terrestrial ecosystems but is also produced in marine ecosystems. In the marine environment, isoprene is produced in the seawater by various biological processes. Here, we show that photosensitized reactions involving the sea-surface microlayer lead to the production of significant amounts of isoprene. It is suggested that H-abstraction processes are initiated by photochemically excited dissolved organic matter which will the degrade fatty acids acting as surfactants. This chemical interfacial processing may represent a significant abiotic source of isoprene in the marine boundary layer.
- ItemEURODELTA III exercise: An evaluation of air quality models’ capacity to reproduce the carbonaceous aerosol(Amsterdam : Elsevier, 2019) Mircea, Mihaela; Bessagnet, Bertrand; D'Isidoro, Massimo; Pirovano, Guido; Aksoyoglu, Sebnem; Ciarelli, Giancarlo; Tsyro, Svetlana; Manders, Astrid; Bieser, Johannes; Stern, Rainer; Vivanco, Marta García; Cuvelier, Cornelius; Aas, Wenche; Prévôt, André S.H.; Aulinger, Armin; Briganti, Gino; Calori, Giuseppe; Cappelletti, Andrea; Colette, Augustin; Couvidat, Florian; Fagerli, Hilde; Finardi, Sandro; Kranenburg, Richard; Rouïl, Laurence; Silibello, Camillo; Spindler, Gerald; Poulain, Laurent; Herrmann, Hartmut; Jimenez, Jose L.; Day, Douglas A.; Tiitta, Petri; Carbone, SamaraThe carbonaceous aerosol accounts for an important part of total aerosol mass, affects human health and climate through its effects on physical and chemical properties of the aerosol, yet the understanding of its atmospheric sources and sinks is still incomplete. This study shows the state-of-the-art in modelling carbonaceous aerosol over Europe by comparing simulations performed with seven chemical transport models (CTMs) currently in air quality assessments in Europe: CAMx, CHIMERE, CMAQ, EMEP/MSC-W, LOTOS-EUROS, MINNI and RCGC. The simulations were carried out in the framework of the EURODELTA III modelling exercise and were evaluated against field measurements from intensive campaigns of European Monitoring and Evaluation Programme (EMEP) and the European Integrated Project on Aerosol Cloud Climate and Air Quality Interactions (EUCAARI). Model simulations were performed over the same domain, using as much as possible the same input data and covering four seasons: summer (1–30 June 2006), winter (8 January – 4 February 2007), autumn (17 September- 15 October 2008) and spring (25 February - 26 March 2009). The analyses of models’ performances in prediction of elemental carbon (EC) for the four seasons and organic aerosol components (OA) for the last two seasons show that all models generally underestimate the measured concentrations. The maximum underestimation of EC is about 60% and up to about 80% for total organic matter (TOM). The underestimation of TOM outside of highly polluted area is a consequence of an underestimation of secondary organic aerosol (SOA), in particular of its main contributor: biogenic secondary aerosol (BSOA). This result is independent on the SOA modelling approach used and season. The concentrations and daily cycles of total primary organic matter (TPOM) are generally better reproduced by the models since they used the same anthropogenic emissions. However, the combination of emissions and model formulation leads to overestimate TPOM concentrations in 2009 for most of the models. All models capture relatively well the SOA daily cycles at rural stations mainly due to the spatial resolution used in the simulations. For the investigated carbonaceous aerosol compounds, the differences between the concentrations simulated by different models are lower than the differences between the concentrations simulated with a model for different seasons. © 2019 The Authors
- ItemBiofunctionalized zinc peroxide (ZnO2) nanoparticles as active oxygen sources and antibacterial agents(London : RSC Publishing, 2017) Bergs, Christian; Brück, Lisa; Rosencrantz, Ruben R.; Conrads, Georg; Elling, Lothar; Pich, AndrijOxygen is one of the most important substances for physiological reactions and metabolisms in biological systems. Through the tailored design of oxygen-releasing materials it might be possible to control different biological processes. In this work we synthesized for the first time zinc peroxide nanoparticles with controlled sizes and biofunctionalized surfaces using a one-step reaction procedure. The zinc peroxide nanoparticles were obtained with tunable sizes (between 4.0 ± 1.2 nm and 9.4 ± 5.2 nm) and were decorated with glucose 1-phosphate (Glc-1P). The specific interaction of the phosphate function of Glc-1P with the nanoparticle surface was monitored by solid state 31P-NMR and zeta-potential measurements. Furthermore, using fluorescence measurements we demonstrated that anchored glucose molecules on the nanoparticle surface are accessible for specific interactions with lectins. It could be shown that these interactions strongly depend on the amount of Glc-1P attached to the nanoparticle surface. Additionally it was demonstrated that the oxygen release from biofunctionalized zinc peroxide nanoparticles could be tuned according to the chemical composition of the nanoparticles and the pH of the aqueous solution. The antibacterial efficiency of the synthesized nanoparticles against Enterococcus faecalis, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia was evaluated by determination of minimal bactericidal concentration (MIC).