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Glycerylphytate as an ionic crosslinker for 3D printing of multi-layered scaffolds with improved shape fidelity and biological features

2020, Mora-Boza, A., Włodarczyk-Biegun, M.K., Del Campo, A., Vázquez-Lasa, B., Román, J.S.

The fabrication of intricate and long-term stable 3D polymeric scaffolds by a 3D printing technique is still a challenge. In the biomedical field, hydrogel materials are very frequently used because of their excellent biocompatibility and biodegradability, however the improvement of their processability and mechanical properties is still required. This paper reports the fabrication of dual crosslinked 3D scaffolds using a low concentrated (<10 wt%) ink of gelatin methacryloyl (GelMA)/chitosan and a novel crosslinking agent, glycerylphytate (G1Phy) to overcome the current limitations in the 3D printing field using hydrogels. The applied methodology consisted of a first ultraviolet light (UV) photopolymerization followed by a post-printing ionic crosslinking treatment with G1Phy. This crosslinker provides a robust framework and avoids the necessity of neutralization with strong bases. The blend ink showed shear-thinning behavior and excellent printability in the form of a straight and homogeneous filament. UV curing was undertaken simultaneously to 3D deposition, which enhanced precision and shape fidelity (resolution ≈150 μm), and prevented the collapse of the subsequent printed layers (up to 28 layers). In the second step, the novel G1Phy ionic crosslinker agent provided swelling and long term stability properties to the 3D scaffolds. The multi-layered printed scaffolds were mechanically stable under physiological conditions for at least one month. Preliminary in vitro assays using L929 fibroblasts showed very promising results in terms of adhesion, spreading, and proliferation in comparison to other phosphate-based traditional crosslinkers (i.e. TPP). We envision that the proposed combination of the blend ink and 3D printing approach can have widespread applications in the regeneration of soft tissues.

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Smart skin patterns protect springtails

2011, Helbig, R., Nickerl, J., Neinhuis, C., Werner, C.

Springtails, arthropods who live in soil, in decaying material, and on plants, have adapted to demanding conditions by evolving extremely effective and robust anti-adhesive skin patterns. However, details of these unique properties and their structural basis are still unknown. Here we demonstrate that collembolan skin can resist wetting by many organic liquids and at elevated pressures. We show that the combination of bristles and a comb-like hexagonal or rhombic mesh of interconnected nanoscopic granules distinguish the skin of springtails from anti-adhesive plant surfaces. Furthermore, the negative overhang in the profile of the ridges and granules were revealed to be a highly effective, but as yet neglected, design principle of collembolan skin. We suggest an explanation for the non-wetting characteristics of surfaces consisting of such profiles irrespective of the chemical composition. Many valuable opportunities arise from the translation of the described comb-like patterns and overhanging profiles of collembolan skin into man-made surfaces that combine stability against wear and friction with superior non-wetting and anti-adhesive characteristics.

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Discovery of 505-million-year old chitin in the basal demosponge Vauxia gracilenta

2013, Ehrlich, H., Rigby, J.K., Botting, J.P., Tsurkan, M.V., Werner, C., Schwille, P., Petrášek, Z., Pisera, A., Simon, P., Sivkov, V.N., Vyalikh, D.V., Molodtsov, S.L., Kurek, D., Kammer, M., Hunoldt, S., Born, R., Stawski, D., Steinhof, A., Bazhenov, V.V., Geisler, T.

Sponges are probably the earliest branching animals, and their fossil record dates back to the Precambrian. Identifying their skeletal structure and composition is thus a crucial step in improving our understanding of the early evolution of metazoans. Here, we present the discovery of 505-million-year-old chitin, found in exceptionally well preserved Vauxia gracilenta sponges from the Middle Cambrian Burgess Shale. Our new findings indicate that, given the right fossilization conditions, chitin is stable for much longer than previously suspected. The preservation of chitin in these fossils opens new avenues for research into other ancient fossil groups.

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Quantification of osseointegration of plasma-polymer coated titanium alloyed implants by means of microcomputed tomography versus histomorphometry

2015, Gabler, Carolin, Zietz, Carmen, Bieck, Richard, Göhler, Rebecca, Lindner, Tobias, Haenle, Maximilian, Finke, Birgit, Meichsner, Jürgen, Testrich, Holger, Nowottnick, Mathias, Frerich, Bernhard, Bader, Rainer

A common method to derive both qualitative and quantitative data to evaluate osseointegration of implants is histomorphometry. The present study describes a new image reconstruction algorithm comparing the results of bone-to-implant contact (BIC) evaluated by means of µCT with histomorphometry data. Custom-made conical titanium alloyed (Ti6Al4V) implants were inserted in the distal tibial bone of female Sprague-Dawley rats. Different surface configurations were examined: Ti6Al4V implants with plasma-polymerized allylamine (PPAAm) coating and plasma-polymerized ethylenediamine (PPEDA) coating as well as implants without surface coating. After six weeks postoperatively, tibiae were explanted and BIC was determined by µCT (3D) and afterwards by histomorphometry (2D). In comparison to uncoated Ti6Al4V implants demonstrating low BIC of 32.4% (histomorphometry) and 51.3% (µCT), PPAAm and PPEDA coated implants showed a nonsignificant increase in BIC (histomorphometry: 45.7% and 53.5% and µCT: 51.8% and 62.0%, resp.). Mean BIC calculated by µCT was higher for all surface configurations compared to BIC detected by histomorphometry. Overall, a high correlation coefficient of 0.70 () was found between 3D and 2D quantification of BIC. The μCT analysis seems to be suitable as a nondestructive and accurate 3D imaging method for the evaluation of the bone-implant interface.

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Persistent effectivity of gas plasma-treated, long time-stored liquid on epithelial cell adhesion capacity and membrane morphology

2014, Hoentsch, M., Bussiahn, R., Rebl, H., Bergemann, C., Eggert, M., Frank, M., Von Woedtke, T., Nebe, B.

Research in plasma medicine includes a major interest in understanding gas plasma-cell interactions. The immediate application of gas plasma in vitro inhibits cell attachment, vitality and cell-cell contacts via the liquid. Interestingly, in our novel experiments described here we found that the liquid-mediated plasma effect is long-lasting after storage up to seven days; i. e. the liquid preserves the characteristics once induced by the argon plasma. Therefore, the complete Dulbecco's Modified Eagle cell culture medium was argon plasma-treated (atmospheric pressure, kINPen09) for 60 s, stored for several days (1, 4 and 7 d) at 37°C and added to a confluent mouse hepatocyte epithelial cell (mHepR1) monolayer. Impaired tight junction architecture as well as shortened microvilli on the cell membrane could be observed, which was accompanied by the loss of cell adhesion capacity. Online-monitoring of vital cells revealed a reduced cell respiration. Our first timedependent analysis of plasma-treated medium revealed that temperature, hydrogen peroxide production, pH and oxygen content can be excluded as initiators of cell physiological and morphological changes. The here observed persisting biological effects in plasma-treated liquids could open new medical applications in dentistry and orthopaedics.

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Charge isomers of myelin basic protein: Structure and interactions with membranes, nucleotide analogues, and calmodulin

2011, Wang, C., Neugebauer, U., Bürck, J., Myllykoski, M., Baumgärtel, P., Popp, J., Kursula, P.

As an essential structural protein required for tight compaction of the central nervous system myelin sheath, myelin basic protein (MBP) is one of the candidate autoantigens of the human inflammatory demyelinating disease multiple sclerosis, which is characterized by the active degradation of the myelin sheath. In this work, recombinant murine analogues of the natural C1 and C8 charge components (rmC1 and rmC8), two isoforms of the classic 18.5-kDa MBP, were used as model proteins to get insights into the structure and function of the charge isomers. Various biochemical and biophysical methods such as size exclusion chromatography, calorimetry, surface plasmon resonance, small angle X-ray and neutron scattering, Raman and fluorescence spectroscopy, and conventional as well as synchrotron radiation circular dichroism were used to investigate differences between these two isoforms, both from the structural point of view, and regarding interactions with ligands, including calmodulin (CaM), various detergents, nucleotide analogues, and lipids. Overall, our results provide further proof that rmC8 is deficient both in structure and especially in function, when compared to rmC1. While the CaM binding properties of the two forms are very similar, their interactions with membrane mimics are different. CaM can be used to remove MBP from immobilized lipid monolayers made of synthetic lipids - a phenomenon, which may be of relevance for MBP function and its regulation. Furthermore, using fluorescently labelled nucleotides, we observed binding of ATP and GTP, but not AMP, by MBP; the binding of nucleoside triphosphates was inhibited by the presence of CaM. Together, our results provide important further data on the interactions between MBP and its ligands, and on the differences in the structure and function between MBP charge isomers.

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Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

2021, Phillips, Helen R. P., Bach, Elizabeth M., Bartz, Marie L. C., Bennett, Joanne M., Beugnon, Rémy, Briones, Maria J. I., Brown, George G., Ferlian, Olga, Gongalsky, Konstantin B., Guerra, Carlos A., König-Ries, Birgitta, López-Hernández, Danilo, Loss, Scott R., Marichal, Raphael, Matula, Radim, Minamiya, Yukio, Moos, Jan Hendrik, Moreno, Gerardo, Morón-Ríos, Alejandro, Motohiro, Hasegawa, Muys, Bart, Krebs, Julia J., Neirynck, Johan, Norgrove, Lindsey, Novo, Marta, Nuutinen, Visa, Nuzzo, Victoria, Mujeeb Rahman, P., Pansu, Johan, Paudel, Shishir, Pérès, Guénola, Pérez-Camacho, Lorenzo, Orgiazzi, Alberto, Ponge, Jean-François, Prietzel, Jörg, Rapoport, Irina B., Rashid, Muhammad Imtiaz, Rebollo, Salvador, Rodríguez, Miguel Á., Roth, Alexander M., Rousseau, Guillaume X., Rozen, Anna, Sayad, Ehsan, Ramirez, Kelly S., van Schaik, Loes, Scharenbroch, Bryant, Schirrmann, Michael, Schmidt, Olaf, Schröder, Boris, Seeber, Julia, Shashkov, Maxim P., Singh, Jaswinder, Smith, Sandy M., Steinwandter, Michael, Russell, David J., Szlavecz, Katalin, Talavera, José Antonio, Trigo, Dolores, Tsukamoto, Jiro, Uribe-López, Sheila, de Valença, Anne W., Virto, Iñigo, Wackett, Adrian A., Warren, Matthew W., Webster, Emily R., Schwarz, Benjamin, Wehr, Nathaniel H., Whalen, Joann K., Wironen, Michael B., Wolters, Volkmar, Wu, Pengfei, Zenkova, Irina V., Zhang, Weixin, Cameron, Erin K., Eisenhauer, Nico, Wall, Diana H., Brose, Ulrich, Decaëns, Thibaud, Lavelle, Patrick, Loreau, Michel, Mathieu, Jérôme, Mulder, Christian, van der Putten, Wim H., Rillig, Matthias C., Thakur, Madhav P., de Vries, Franciska T., Wardle, David A., Ammer, Christian, Ammer, Sabine, Arai, Miwa, Ayuke, Fredrick O., Baker, Geoff H., Baretta, Dilmar, Barkusky, Dietmar, Beauséjour, Robin, Bedano, Jose C., Birkhofer, Klaus, Blanchart, Eric, Blossey, Bernd, Bolger, Thomas, Bradley, Robert L., Brossard, Michel, Burtis, James C., Capowiez, Yvan, Cavagnaro, Timothy R., Choi, Amy, Clause, Julia, Cluzeau, Daniel, Coors, Anja, Crotty, Felicity V., Crumsey, Jasmine M., Dávalos, Andrea, Cosín, Darío J. Díaz, Dobson, Annise M., Domínguez, Anahí, Duhour, Andrés Esteban, van Eekeren, Nick, Emmerling, Christoph, Falco, Liliana B., Fernández, Rosa, Fonte, Steven J., Fragoso, Carlos, Franco, André L. C., Fusilero, Abegail, Geraskina, Anna P., Gholami, Shaieste, González, Grizelle, Gundale, Michael J., López, Mónica Gutiérrez, Hackenberger, Branimir K., Hackenberger, Davorka K., Hernández, Luis M., Hirth, Jeff R., Hishi, Takuo, Holdsworth, Andrew R., Holmstrup, Martin, Hopfensperger, Kristine N., Lwanga, Esperanza Huerta, Huhta, Veikko, Hurisso, Tunsisa T., Iannone, Basil V., Iordache, Madalina, Irmler, Ulrich, Ivask, Mari, Jesús, Juan B., Johnson-Maynard, Jodi L., Joschko, Monika, Kaneko, Nobuhiro, Kanianska, Radoslava, Keith, Aidan M., Kernecker, Maria L., Koné, Armand W., Kooch, Yahya, Kukkonen, Sanna T., Lalthanzara, H., Lammel, Daniel R., Lebedev, Iurii M., Le Cadre, Edith, Lincoln, Noa K.

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.