Search results for "Note"

Organization into Higher Ordered Ring Structures Counteracts Membrane Binding of IM30, a Protein Associated with Inner Membranes in Chloroplasts and …

2016

The IM30 (inner membrane-associated protein of 30 kDa), also known as the Vipp1 (vesicle-inducing protein in plastids 1), has a crucial role in thylakoid membrane biogenesis and maintenance. Recent results suggest that the protein binds peripherally to membranes containing negatively charged lipids. However, although IM30 monomers interact and assemble into large oligomeric ring complexes with different numbers of monomers, it is still an open question whether ring formation is crucial for membrane interaction. Here we show that binding of IM30 rings to negatively charged phosphatidylglycerol membrane surfaces results in a higher ordered membrane state, both in the head group and in the inn…

Squalene versus cholesterol: Which is the best nanocarrier for the delivery to cells of the anticancer drug gemcitabine?

2018

Comptes Rendus Chimie - In Press.Proof corrected by the author Available online since jeudi 22 mars 2018

Fourier transform infrared analysis of commercial formulations for Varroa treatment

2017

A comparative study has been carried out between univariate and multivariate calibration strategies for the simultaneous determination of camphor, thymol, menthol and eucalyptol in commercial formulations used for Varroa treatment. Absorbance peak heights of the transmission mid-infrared (MIR) spectra of individual monoterpenes, prepared in dichloromethane, were measured at 1737, 1151, 1022 and 980 cm−1 (corrected with a base-line at 1933 cm−1) for camphor, thymol, menthol and eucalyptol, respectively. Data were processed using the proportional equations approach in univariate mode. For multivariate calibration, partial least squares (PLS) regression based on a classical 42 design for stand…

A new approach for the treatment of CLL using chlorambucil/hydroxychloroquine-loaded anti-CD20 nanoparticles

2015

Current approaches for the treatment of chronic lymphocytic leukemia (CLL) have greatly improved the prognosis for survival, but some patients remain refractive to these therapeutic regimens. Hence, in addition to reducing the long-term sideeffects of therapeutics for all leukemia patients, there is an urgent need for novel therapeutic strategies for difficult-to-treat leukemia cases. Due to the cytotoxicity of drugs, the major challenge currently is to deliver the therapeutic agents to neoplastic cells while preserving the viability of non-malignant cells. In this study, we propose a therapeutic approach in which high doses of hydroxychloroquine and chlorambucil were loaded into biodegrada…

Ethanol Controls the Self-Assembly and Mesoscopic Properties of Human Insulin Amyloid Spherulites.

2018

Protein self-assembly into amyloid fibrils or highly hierarchical superstructures is closely linked to neurodegenerative pathologies as Alzheimer's and Parkinson's diseases. Moreover, protein assemblies also emerged as building blocks for bioinspired nanostructured materials. In both the above mentioned fields, the main challenge is to control the growth and properties of the final protein structure. This relies on a more fundamental understanding of how interactions between proteins can determine structures and functions of biomolecular aggregates. Here, we identify a striking effect of the hydration of the single human insulin molecule and solvent properties in controlling hydrophobicity/…

Stabilization and detection of hydrophylloquinone as di-O-methyl derivative

2016

Phylloquinone is a redox active naphthoquinone involved in electron transport in plants. The function of this reduced form remains unclear due to its instability, which has precluded detection. Herein, a simple method that permits the stabilization of the reduced form of phylloquinone by di-O-methylation and HPLC detection is described. Fil: Sussmann, Rodrigo A. C.. Universidade de Sao Paulo; Brasil Fil: de Moraes, Marcilio M.. Universidade de Sao Paulo; Brasil Fil: Cebrián Torrejón, Gerardo. Universidad de Valencia; España. Universidade de Sao Paulo; Brasil Fil: Porta, Exequiel Oscar Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - …

2017

Although a lot of research has been performed, large segmental bone defects caused by trauma, infection, bone tumors or revision surgeries still represent big challenges for trauma surgeons. New and innovative bone substitutes are needed. Three-dimensional (3D) printing is a novel procedure to create 3D porous scaffolds that can be used for bone tissue engineering. In the present study, solid discs as well as porous cage-like 3D prints made of polylactide (PLA) are coated or filled with collagen, respectively, and tested for biocompatibility and endotoxin contamination. Microscopic analyses as well as proliferation assays were performed using various cell types on PLA discs. Stromal-derived…

Collective behavior of quorum-sensing run-and-tumble particles in confinement

2016

We study a generic model for quorum-sensing bacteria in circular confinement. Every bacterium produces signaling molecules, the local concentration of which triggers a response when a certain threshold is reached. If this response lowers the motility then an aggregation of bacteria occurs, which differs fundamentally from standard motility-induced phase separation due to the long-ranged nature of the concentration of signal molecules. We analyze this phenomenon analytically and by numerical simulations employing two different protocols leading to stationary cluster and ring morphologies, respectively.

Cohesive Model for the Simulation of Crack Initiation and Propagation in Mixed-Mode I/II in Composite Materials

2019

A cohesive element able to connect and simulate crack growth between independently modeled finite element subdomains with non-matching meshes is proposed and validated. The approach is based on penalty constraints and has several advantages over conventional FE techniques in disconnecting two regions of a model during crack growth. The most important is the ability to release portion of the interface that are smaller than the local finite element length. Thus, the growth of delamination is not limited to advancing by releasing nodes of the FE model, which is a limitation common to the methods found in the literature. Furthermore, it is possible to vary the penalty parameter within the cohes…

Uptake of polyphosphate microparticles in vitro (SaOS-2 and HUVEC cells) followed by an increase of the intracellular ATP pool size

2017

Recently two approaches were reported that addressed a vitally important problem in regenerative medicine, i. e. the successful treatment of wounds even under diabetic conditions. Accordingly, these studies with diabetic rabbits [Sarojini et al. PLoS One 2017, 12(4):e0174899] and diabetic mice [Müller et al. Polymers 2017, 9, 300] identified a novel (potential) target for the acceleration of wound healing in diabetes. Both studies propose a raise of the intracellular metabolic energy status via exogenous administration either of ATP, encapsulated into lipid vesicles, or of polyphosphate (polyP) micro-/nanoparticles. Recently this physiological polymer, polyP, was found to release metabolic …