Search results for "Bioengineering"
showing 10 items of 1963 documents
Application of Electronic Nose for Evaluation of Wastewater Treatment Process Effects at Full-Scale WWTP
2019
This paper presents the results of studies aiming at the assessment and classification of wastewater using an electronic nose. During the experiment, an attempt was made to classify the medium based on an analysis of signals from a gas sensor array, the intensity of which depended on the levels of volatile compounds in the headspace gas mixture above the wastewater table. The research involved samples collected from the mechanical and biological treatment devices of a full-scale wastewater treatment plant (WWTP), as well as wastewater analysis. The measurements were carried out with a metal-oxide-semiconductor (MOS) gas sensor array, when coupled with a computing unit (e.g., a computer with…
Electrostatically Driven Complexation of Liposomes with a Star-Shaped Polyelectrolyte to Low-Toxicity Multi-Liposomal Assemblies
2013
Anionic liposomes are electrostatically complexed to a star-shaped cationic polyelectrolyte. Upon complexation, the liposomes retain their integrity and the resulting liposome-star complexes do not dissociate in a physiological solution with 0.15 M NaCl. This provides a multi-liposomal container for possible use as a high-capacity carrier.
A plasma protein corona enhances the biocompatibility of Au@Fe3O4 Janus particles
2015
AbstractAu@Fe3O4 Janus particles (JPs) are heteroparticles with discrete domains defined by different materials. Their tunable composition and morphology confer multimodal and versatile capabilities for use as contrast agents and drug carriers in future medicine. Au@Fe3O4 JPs have colloidal properties and surface characteristics leading to interactions with proteins in biological fluids. The resulting protein adsorption layer (“protein corona”) critically affects their interaction with living matter. Although Au@Fe3O4 JPs displayed good biocompatibility in a standardized in vitro situation, an in-depth characterization of the protein corona is of prime importance to unravel underlying mecha…
Reversible Strong Coupling in Silver Nanoparticle Arrays Using Photochromic Molecules
2012
International audience; In this Letter, we demonstrate a reversible strong coupling regime between a dipolar surface plasmon resonance and a molecular excited state. This reversible state is experimentally observed on silver nanoparticle arrays embedded in a polymer film containing photochromic molecules. Extinction measurements reveal a clear Rabi splitting of 294 meV, corresponding to ∼13% of the molecular transition energy. We derived an analytical model to confirm our observations, and we emphasize the importance of spectrally matching the polymer absorption with the plasmonic resonance to observe coupled states. Finally, the reversibility of this coupling is illustrated by cycling the …
Systems level approach reveals the correlation of endoderm differentiation of mouse embryonic stem cells with specific microstructural cues of fibrin…
2014
Stem cells receive numerous cues from their associated substrate that help to govern their behaviour. However, identification of influential substrate characteristics poses difficulties because of their complex nature. In this study, we developed an integrated experimental and systems level modelling approach to investigate and identify specific substrate features influencing differentiation of mouse embryonic stem cells (mESCs) on a model fibrous substrate, fibrin. We synthesized a range of fibrin gels by varying fibrinogen and thrombin concentrations, which led to a range of substrate stiffness and microstructure. mESCs were cultured on each of these gels, and characterization of the diff…
Assessment of cross-flow filtration as microalgae harvesting technique prior to anaerobic digestion: Evaluation of biomass integrity and energy demand
2018
[EN] In the present study, the effect of cross-flow filtration (CFF) on the overall valorization of Chlorella spp. microalgae as biogas was assessed. The effect of CFF on microalgae cell integrity was quantified in terms of viability which was correlated with the anaerobic biodegradability. The viability dropped as the biomass concentration increased, whereas anaerobic biodegradability increased linearly with the viability reduction. It was hypothesized that a stress-induced release and further accumulation of organic polymers during CFF increased the flux resistance which promoted harsher shear-stress conditions. Furthermore, the volume reduction as the concentration increased entailed an …
In vitro antibacterial activity of different pulp capping materials
2015
Background: Direct pulp capping involves the application of a dental material to seal communications between the exposed pulp and the oral cavity (mechanical and carious pulp exposures) in an attempt to act as a barrier, protect the dental pulp complex and preserve its vitality. The aim of this study was to evaluate and compare, by the agar disc diffusion test, the antimicrobial activity of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), Biodentine (Septodont). Material and Methods: Streptococcus salivarius , Streptococcus sanguis and Streptococcus mutans strains were selected to evaluate the antimicrob…
Engineering a morphogenetically active hydrogel for bioprinting of bioartificial tissue derived from human osteoblast-like SaOS-2 cells.
2014
Abstract Sodium alginate hydrogel, stabilized with gelatin, is a suitable, biologically inert matrix that can be used for encapsulating and 3D bioprinting of bone-related SaOS-2 cells. However, the cells, embedded in this matrix, remain in a non-proliferating state. Here we show that addition of an overlay onto the bioprinted alginate/gelatine/SaOS-2 cell scaffold, consisting of agarose and the calcium salt of polyphosphate [polyP·Ca 2+ -complex], resulted in a marked increase in cell proliferation . In the presence of 100 μ m polyP·Ca2+ -complex, the cells proliferate with a generation time of approximately 47–55 h. In addition, the hardness of the alginate/gelatin hydrogel substantially i…
Inorganic phosphate is a trigger factor for Microbispora sp. ATCC-PTA-5024 growth and NAI-107 production
2014
Background NAI-107, produced by the actinomycete Microbispora sp. ATCC-PTA-5024, is a promising lantibiotic active against Gram-positive bacteria and currently in late preclinical-phase. Lantibiotics (lanthionine-containing antibiotics) are ribosomally synthesized and post-translationally modified peptides (RiPPs), encoded by structural genes as precursor peptides. The biosynthesis of biologically active compounds is developmentally controlled and it depends upon a variety of environmental stimuli and conditions. Inorganic phosphate (Pi) usually negatively regulates biologically-active molecule production in Actinomycetes, while it has been reported to have a positive control on lantibiotic…
Porous Gelatin Hydrogels: 2. In Vitro Cell Interaction Study
2007
We report on the feasibility of applying porous gelatin hydrogels, prepared by a novel and controlled cryogenic treatment, as cell-interactive scaffolds for tissue engineering applications. Despite the large number of publications on gelatin as a biomaterial, a detailed study of screening a limited number of gelatin scaffolds for their interaction with a panel of human cells has, to the best of our knowledge, not yet been published. In the present work, we have evaluated two types of porous gelatin scaffolds that differ in their pore geometry and pore size. Type I hydrogels contained top-to-bottom transverse channels (i.e. cones) with a decreasing diameter from the top (330 microm) to the b…