Search results for "Bioengineering"
showing 10 items of 1963 documents
Organic matrices in metazoan calcium carbonate skeletons: composition, functions, evolution.
2016
9 pages; International audience; Calcium carbonate skeletal tissues in metazoans comprise a small quantity of occluded organic macromolecules, mostly proteins and polysaccharides that constitute the skeletal matrix. Because its functions in modulating the biomineralization process are well known, the skeletal matrix has been extensively studied, successively via classical biochemical approaches, via molecular biology and, in recent years, via transcriptomics and proteomics. The optimistic view that the deposition of calcium carbonate minerals requires a limited number of macromolecules has been challenged, in the last decade, by high-throughput approaches. Such approaches have made possible…
A minimal molecular toolkit for mineral deposition? Biochemistry and proteomics of the test matrix of adult specimens of the sea urchin Paracentrotus…
2016
12 pages; International audience; The sea urchin endoskeleton consists of a magnesium-rich biocalcite comprising a small amount of occluded organic macromolecules. This structure constitutes a key-model for understanding the mineral - organics interplay, and for conceiving in vitro bio-inspired materials with tailored properties. Here we employed a deep-clean technique to purify the occluded proteins from adult Paracentrotus lividus tests. We characterized them by 1- and 2D-electrophoreses, ELISA and immunoblotting, and using liquid chromatography coupled with Mass Spectrometry (nanoLC-MS/MS), we identified two metalloenzymes (carbonic anhydrase and MMP), a set of MSP130 family members, sev…
Skin-derived mesenchymal stem cells as quantum dot vehicles to tumors
2017
Dominyka Dapkute,1,2 Simona Steponkiene,1 Danute Bulotiene,1 Liga Saulite,3 Una Riekstina,3 Ricardas Rotomskis1,4 1Biomedical Physics Laboratory, National Cancer Institute, Vilnius, Lithuania; 2Institute of Biosciences, Vilnius University, Vilnius, Lithuania; 3Faculty of Medicine, University of Latvia, Riga, Latvia; 4Biophotonics Group of Laser Research Center, Faculty of Physics, Vilnius University, Vilnius, Lithuania Purpose: Cell-mediated delivery of nanoparticles is emerging as a new method of cancer diagnostics and treatment. Due to their inherent regenerative properties, adult mesenchymal stem cells (MSCs) are naturally attracted to wounds and sites of inflammation, as well as tumors.…
Microenvironments to study migration and somal translocation in cortical neurons
2018
Migrating post-mitotic neurons of the developing cerebral cortex undergo terminal somal translocation (ST) when they reach their final destination in the cortical plate. This process is crucial for proper cortical layering and its perturbation can lead to brain dysfunction. Here we present a reductionist biomaterials platform that faithfully supports and controls the distinct phases of terminal ST in vitro. We developed microenvironments with different adhesive molecules to support neuronal attachment, neurite extension, and migration in distinct manners. Efficient ST occurred when the leading process of migratory neurons crossed from low-to high-adhesive areas on a substrate, promoting spr…
Yeast biota of naturally fermented black olives in different brines made from cv. Gemlik grown in various districts of the Cukurova region of Turkey
2016
In this study, the yeast microbiota of naturally fermented black olives made from cv. Gemlik, grown in three different districts of the Cukurova region of Turkey, were investigated. Fermentations were conducted for 180 days in three different brines, including NaCl 10% w/v, NaCl 8% w/v and NaCl 8% w/v added with glucose 0.5%. In total, 223 yeasts were isolated and then identified by PCR-RFLP analysis of the 5.8S ITS rRNA region and sequence information for the D1/D2 domains of the 26S rRNA gene. A broad range of yeast biodiversity was identified, including eight genera and nine species. Candida boidinii (41%), Wickerhamomyces anomalus (32%) and Saccharomyces sp. (18%) were predominant yeast…
Bifunctional Hydrogels Containing the Laminin Motif IKVAV Promote Neurogenesis
2017
Summary Engineering of biomaterials with specific biological properties has gained momentum as a means to control stem cell behavior. Here, we address the effect of bifunctionalized hydrogels comprising polylysine (PL) and a 19-mer peptide containing the laminin motif IKVAV (IKVAV) on embryonic and adult neuronal progenitor cells under different stiffness regimes. Neuronal differentiation of embryonic and adult neural progenitors was accelerated by adjusting the gel stiffness to 2 kPa and 20 kPa, respectively. While gels containing IKVAV or PL alone failed to support long-term cell adhesion, in bifunctional gels, IKVAV synergized with PL to promote differentiation and formation of focal adh…
Polymeric hepatitis C virus non-structural protein 5A nanocapsules induce intrahepatic antigen-specific immune responses
2016
Targeting antigen combined with adjuvants to hepatic antigen-presenting cells (APCs) is essential for the induction of intrahepatic T cellular immunity controlling and resolving viral infections of the liver. Intravenous injection of antigen-loaded nanoparticles is a promising approach for the delivery of antigens to liver APCs. Accordingly, polymeric nanocapsules (NCs) synthesized exclusively of hepatitis C virus non-structural protein 5A (NS5A) and the adjuvant monophosphoryl lipid A (MPLA) adsorbed to the nanocapsule surface were developed. Aim of the present study was the evaluation of the in vitro and in vivo behavior of MPLA-functionalized NS5A-NCs regarding the interaction with liver…
Lasiolactols A and B Produced by the Grapevine Fungal Pathogen Lasiodiplodia mediterranea
2016
A strain of Lasiodiplodia mediterranea, a fungus associated with grapevine decline in Sicily, produced several metabolites in liquid medium. Two new dimeric c-lactols, lasiolactols A and B (1 and 2), were characterized as (2S*,3S*,4R*,5R*,20S*,30S*,40R*,50R*)-and (2R*,3S*,4R*,5R*,20R*,30S*,40R*,50R*)-(5-(4-hydroxymethyl-3,5-dimethyl-tetrahydrofuran- 2-yloxy)-2,4-dimethyl-tetrahydro-furan-3-yl]-methanols by IR, 1D-and 2D-NMR, and HR-ESI-MS. Other four metabolites were identified as botryosphaeriodiplodin, (5R)-5-hydroxylasiodiplodin, (-)-(1R, 2R)-jasmonic acid, and (-)-(3S, 4R, 5R)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone (3 - 6, resp.). The absolute configuration (R) at hydroxylated s…
A New Niche for Anoxygenic Phototrophs as Endoliths
2018
ABSTRACT Anoxygenic phototrophic bacteria (APBs) occur in a wide range of aquatic habitats, from hot springs to freshwater lakes and intertidal microbial mats. Here, we report the discovery of a novel niche for APBs: endoliths within marine littoral carbonates. In a study of 40 locations around Isla de Mona, Puerto Rico, and Menorca, Spain, 16S rRNA high-throughput sequencing of endolithic community DNA revealed the presence of abundant phylotypes potentially belonging to well-known APB clades. An ad hoc phylogenetic classification of these sequences enabled us to refine the assignments more stringently. Even then, all locations contained such putative APBs, often reaching a significant pro…
Thermal stability of nacre proteins of the polynesian pearl oyster: a proteomic study.
2015
Mollusc shells are organic-inorganic composites that are often preserved in the fossil record. However, the way the organic fraction, also called shell matrix, gets fossilized remains an unsolved question, in spite of several old and more recent studies. In the present paper, we have tried to mimic a diagenetic process by constantly heating for ten days at 100°C fresh nacre powder samples of the Polynesian pearl oyster Pinctadamargaritifera. Each day, aliquots of nacre powder were sampled and the matrix was subsequently extracted. It was further analysed by direct weigh quantification, by immunological techniques and by proteomics. Our preliminary data suggest that nacre proteins, when heat…