Search results for "bioengineering"
showing 10 items of 1963 documents
Impact of Branching on the Solution Behavior and Serum Stability of Starlike Block Copolymers.
2019
The size control of nanomedicines for tumor diagnosis and therapy is of high importance, since it enables or disables deep and sufficient tumor penetration. Amphiphilic star-shaped block copolypept(o)ides offer substantial promise to precisely adjust the hydrophobic core and the hydrophilic corona, independent of each other, and therefore simultaneously control the size dimension in the interesting size range from 10 to 30 nm. To gain access to core-shell structures of such sizes, 3-arm and 6-arm PeptoStars, based on poly(gamma-tert-butyloxycarbonyl-L-glutamate)-b-polysarcosine (pGlu(OtBu)-b-pSar), were prepared via controlled living ring-opening polymerization (ROP) of the corresponding N-…
Denaturation via Surfactants Changes Composition of Protein Corona
2018
The use of nanocarriers as drug delivery vehicles brings them into contact with blood plasma proteins. Polymeric nanocarriers require some sort of surfactant to ensure colloidal stability. Formation of the protein corona is therefore determined not only by the intrinsic properties of the nanocarrier itself but also by the accompanying surfactant. Although it is well-known that surfactants have an impact on protein structure, only few studies were conducted on the specific effect of surfactants on the composition of protein corona of nanocarriers. Therefore, we analyzed the composition of the protein corona on "stealth" nanoparticles with additional surfactant (cetyltrimethylammonium chlorid…
Single Unlabeled Protein Detection on Individual Plasmonic Nanoparticles
2012
The ultimate detection limit in analytic chemistry and biology is the single molecule. Commonly, fluorescent dye labels or enzymatic amplification are employed. This requires additional labeling of the analyte, which modifies the species under investigation and therefore influences biological processes. Here, we utilize single gold nanoparticles to detect single unlabeled proteins with extremely high temporal resolution. This allows for monitoring the dynamic evolution of a single protein binding event on a millisecond time scale. The technique even resolves equilibrium coverage fluctuations, opening a window into Brownian dynamics of unlabeled macromolecules. Therefore, our method enables …
Acute cytotoxicity and apoptotic effects after l-Pam exposure in different cocultures of the proximal and distal respiratory system.
2009
Abstract Sulphur and nitrogen mustard are strong alkylating agents which can cause after inhalation acute lung injury in the larynx, trachea and large bronchi and can lead to alveolar edema. In our study we tested the N-Lost l -Phenylalanine Mustard ( l -Pam). Therefore we seeded the alveolar type II cell line NCI H441 on the upper membrane of a Transwell filter plate and the endothelial cell line ISO-Has-1 on the lower side of the membrane for the alveolar model and combined the human bronchial explant-outgrowth cells and fibroblasts in the bronchial model and exposed both models with various concentrations of l -Pam. Treatment with l -Pam led to a concentration-dependent decrease of the t…
Global transcriptional profiling ofCandida albicans cwt1 null mutant
2007
CaCwt1p is a Candida albicans putative transcriptional factor homologue to Rds2p in Saccharomyces cerevisiae. The lack of this protein in S. cerevisiae leads to a pleiotropic resistance to drugs and defects in cell wall architecture that are also detectable in C. albicans. It is also known that CaCwt1p is mainly expressed in the stationary growth phase of this fungus. In order to elucidate the role of CWT1, transcriptome analysis of the mutant strain was performed in exponential and stationary growth phases. A total of 460 genes were found to be up- or downregulated in the mutant strain growing exponentially, and 666 genes presented a misregulation when cwt1 cells reached the stationary pha…
Evolution of nacre: biochemistry and proteomics of the shell organic matrix of the cephalopod Nautilus macromphalus.
2009
12 pages; International audience; In mollusks, one of the most widely studied shell textures is nacre, the lustrous aragonitic layer that constitutes the internal components of the shells of several bivalves, a few gastropods, and one cephalopod: the nautilus. Nacre contains a minor organic fraction, which displays a wide range of functions in relation to the biomineralization process. Here, we have biochemically characterized the nacre matrix of the cephalopod Nautilus macromphalus. The acid-soluble matrix contains a mixture of polydisperse and discrete proteins and glycoproteins, which interact with the formation of calcite crystals. In addition, a few bind calcium ions. Furthermore, we h…
Differential proteomic analysis highlights metabolic strategies associated with balhimycin production in Amycolatopsis balhimycina chemostat cultivat…
2010
Abstract Background Proteomics was recently used to reveal enzymes whose expression is associated with the production of the glycopeptide antibiotic balhimycin in Amycolatopsis balhimycina batch cultivations. Combining chemostat fermentation technology, where cells proliferate with constant parameters in a highly reproducible steady-state, and differential proteomics, the relationships between physiological status and metabolic pathways during antibiotic producing and non-producing conditions could be highlighted. Results Two minimal defined media, one with low Pi (0.6 mM; LP) and proficient glucose (12 g/l) concentrations and the other one with high Pi (1.8 mM) and limiting (6 g/l; LG) glu…
Proteomic analysis of Parietaria judaica pollen and allergen profiling by an immunoproteomic approach
2010
Parietaria judaica pollen is a common cause of airway allergic disease in the Mediterranean area. Proteome analysis of mature Parietaria judaica pollen by two-dimensional gel electrophoresis (2-DE) and mass spectrometry has established the first reference proteome map of this weed. Proteins involved in a variety of cellular functions as well as the occurrence of allergens were detected. By using 2-DE and immunoblotting with sera from Parietaria judaica allergic patients we obtained a more detailed characterization of Parietaria judaica allergen profile so to improve our comprehension of the pathogenesis of pollen-induced allergic reaction.
The skeleton of the staghorn coral Acropora millepora: molecular and structural characterization.
2014
15 pages; International audience; The scleractinian coral Acropora millepora is one of the most studied species from the Great Barrier Reef. This species has been used to understand evolutionary, immune and developmental processes in cnidarians. It has also been subject of several ecological studies in order to elucidate reef responses to environmental changes such as temperature rise and ocean acidification (OA). In these contexts, several nucleic acid resources were made available. When combined to a recent proteomic analysis of the coral skeletal organic matrix (SOM), they enabled the identification of several skeletal matrix proteins, making A. millepora into an emerging model for biomi…
Proteomics of CaCO3 biomineral-associated proteins: how to properly address their analysis.
2013
8 pages; International audience; In a recent editorial (Proc. Natl. Acad. Sci., 2013 110, E2144-E2146) and elsewhere, questions have been raised regarding the experimental practices in relation to the proteomic analysis of organic matrices associated to the biomineralized CaCO3 skeletons of metazoans such as molluscan shells and coral skeletons. Indeed, although the use of new high sensitivity MS technology potentially allows to identify a greater number of proteins, it is also equally (or even more) sensitive to contamination of residual proteins from soft tissues, which are in close contact with the biomineral. Based on our own past and present experimental know-how-observations that are …