Search results for "Mimetic"

Template-Assembled Synthetic G-Quartets (TASQ) hydrosolubles : du ligand de quadruplexes d'ADN et d'ARN à la plateforme catalytique

2013

Natural G-quartets, a cyclic and coplanar array of four guanine residues held together via Hoogsteen H-bond network, have recently received much attention due to their involvement in G-quadruplex-DNA, an alternative higher-order DNA structure strongly suspected to play important roles in key cellular events (chromosomal stability, regulation of gene expression). Besides this, synthetic G-quartets, which artificially mimic native G-quartets, have also been widely studied for their involvement in nanotechnological applications (i.e. nanowires, artificial ion channels, etc.). In contrast, intramolecular synthetic G-quartets, also named template-assembled synthetic G-quartet (TASQ), have been m…

Tetraalkylammonium Cations Conduction through a Single Nanofluidic Diode: Experimental and Theoretical Studies

2017

[EN] We describe experimentally and theoretically the concentration-dependent conduction of tetraalkylammonium (TAA+) cations through a nanofluidic diode fabricated in a polymer membrane via asymmetric track-etching techniques. This single-pore membrane exhibits current rectification characteristics because of the ionized carboxylate groups on the pore surface. We use aqueous solutions of potassium (K+ ), ammonium (A+ ), tetramethylammonium (TMA+ ), tetraethylammonium (TEA+ ), and tetrabutylammonium (TBA+ ) ions with concentrations ranging from 50 to 500 mM under acidic (pH 3.5) and physiological (pH 6.5) conditions. Compared with the K+ and A+ ions, the TMA+ , TEA+ , and TBA+ ions show rel…

Controlled Crystallization of CaCO3on Hyperbranched Polyglycerol Adsorbed to Self-Assembled Monolayers

2005

The formation of biominerals by living organisms is governed by the cooperation of soluble and insoluble macromolecules with peculiar interfacial properties. To date, most of the studies on mineralization processes involve model systems that only account for the existence of one organic matrix and thus disregard the interaction between the soluble and insoluble organic components that is crucial for a better understanding of the processes taking place at the inorganic-organic interface. We have set up a model system composed of a matrix surface, namely, a self-assembled monolayer (SAM), and a soluble component, hyperbranched polyglycerol. The model mineral calcium carbonate displays diverse…

Fabrication of elastomeric scaffolds with curvilinear fibrous structures for heart valve leaflet engineering

2014

Native semi-lunar heart valves are composed of a dense fibrous network that generally follows a curvilinear path along the width of the leaflet. Recent models of engineered valve leaflets have predicted that such curvilinear fiber orientations would homogenize the strain field and reduce stress concentrations at the commissure. In the present work, a method was developed to reproduce this curvilinear fiber alignment in electrospun scaffolds by varying the geometry of the collecting mandrel. Elastomeric poly(ester urethane)urea was electrospun onto rotating conical mandrels of varying angles to produce fibrous scaffolds where the angle of fiber alignment varied linearly over scaffold length.…

2019

Despite substantial advances in many different fields of neurorobotics in general, and biomimetic robots in particular, a key challenge is the integration of concepts: to collate and combine research on disparate and conceptually disjunct research areas in the neurosciences and engineering sciences. We claim that the development of suitable robotic integration platforms is of particular relevance to make such integration of concepts work in practice. Here, we provide an example for a hexapod robotic integration platform for autonomous locomotion. In a sequence of six focus sections dealing with aspects of intelligent, embodied motor control in insects and multipedal robots-ranging from comp…

Forchlorfenuron-mimicking haptens: From immunogen design to antibody characterization by hierarchical clustering analysis

2011

To obtain highly-specific and selective forchlorfenuron binders, a collection of functionalized derivatives with different spacer arm locations and lengths was prepared. By immunization with target-mimicking haptens, a large battery of monoclonal and polyclonal antibodies against this synthetic cell regulator was produced and exhaustively characterized in two immunoassay formats using homologous and heterologous conjugates. Antibodies with IC50 values lower than 0.3 nM were successfully raised from the prepared immunogens, thus evidencing the efficacy of the explored strategies. In order to identify significant epitopes in the antibody-antigen interaction, a series of new chemical forchlorf…

Arginine-Rich Peptidomimetic Ampicillin/Gentamicin Conjugate To Tackle Nosocomial Biofilms: A Promising Strategy To Repurpose First-Line Antibiotics

2023

: Combined therapy with penicillins and aminoglycosides has been proved beneficial to address many persistent bacterial infections with possible synergistic effects. However, the different pharmacokinetic profiles of these two antibiotic classes may not guarantee a concerted spatio-temporal delivery at the site of action, decreasing the efficacy of this combination and promoting resistance. Herein, we propose a multifunctional antibiotic-polymer conjugate, designed to colocalize ampicillin and gentamicin to tackle persistent biofilm infections. The two antibacterial molecules were grafted along with the amino acid l-arginine to a biocompatible polymer backbone with peptidomimetic hydrophili…

Biomimetic Alginate/Gelatin Cross-Linked Hydrogels Supplemented with Polyphosphate for Wound Healing Applications

2020

In the present study, the fabrication of a biomimetic wound dressing that mimics the extracellular matrix, consisting of a hydrogel matrix composed of non-oxidized and periodate-oxidized marine alginate, was prepared to which gelatin was bound via Schiff base formation. Into this alginate/oxidized-alginate-gelatin hydrogel, polyP was stably but reversibly integrated by ionic cross-linking with Zn2+ ions. Thereby, a soft hybrid material is obtained, consisting of a more rigid alginate scaffold and porous structures formed by the oxidized-alginate-gelatin hydrogel with ionically cross-linked polyP. Two forms of the Zn-polyP-containing matrices were obtained based on the property of polyP to f…

Challenge of tacit knowledge in acquiring information in cognitive mimetics

2019

Intelligent technologies are rising. This is why methods for designing them are important. One approach is to study how people process information in carrying out intelligence demanding tasks and use this information in designing new technology solutions. This approach can be called cognitive mimetics. A problem in mimetics is to explicate tacit or subconscious knowledge. Here, we study a combination of thinking aloud in ship simulator driving and focus group commenting the solutions of subjects. On the ground of these early experiments, a multiple method combination seems to be the best way forward to solve problems of tacit or subconscious knowledge. peerReviewed

Resveratrol-Related Dehydrodimers: Laccase-Mediated Biomimetic Synthesis and Antiproliferative Activity

2012

Seven resveratrol-related monomeric stilbenoids were submitted to biomimetic oxidative coupling in the presence of laccase from Trametes versicolor (TvL), and gave racemic dihydrobenzofuran dehydrodimers (±)-15 to (±)-21. These products, after spectral characterization, were submitted to an antiproliferative activity bioassay against SW480 human colon cancer cells. Five racemates were found to be active, and were resolved by chiral HPLC. The pure enantiomers were subjected to circular dichroism measurements to establish their absolute configurations at C-7 and C-8. These enantiomerically pure compounds were submitted to the antiproliferative activity assay towards SW480 cells, and were all …