Search results for "N-2"

Biocompatible micelles based on squalene portions linked to pegylated polyaspartamide as potential colloidal drug carriers

2011

Mucus and Cell-Penetrating Nanoparticles Embedded in Nano-into-Micro Formulations for Pulmonary Delivery of Ivacaftor in Patients with Cystic Fibrosis

2017

Here, mucus-penetrating nanoparticles (NPs) for pulmonary administration of ivacaftor in patients with cystic fibrosis (CF) were produced with the dual aim of enhancing ivacaftor delivery to the airway epithelial cells, by rapid diffusion through the mucus barrier, and at the same time, promoting ivacaftor lung cellular uptake. Pegylated and Tat-decorated fluorescent nanoparticles (FNPs) were produced by nanoprecipitation, starting from two synthetic copolymers, and showed nanometric sizes (∼70 nm), a slightly negative ζ potential, and high cytocompatibility toward human bronchial epithelium cells. After having showed the significant presence of poly(ethylene glycol) chains and Tat protein …

Polyaspartamide-based nanoparticles loaded with fluticasone propionate and the in vitro evaluation towards cigarette smoke effects

2017

This paper describes the evaluation of polymeric nanoparticles (NPs) as a potential carrier for lung administration of fluticasone propionate (FP). The chosen polymeric material to produce NPs was a copolymer based on α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) whose backbone was derivatised with different molecules, such as poly(lactic acid) (PLA) and polyethylenglycol (PEG). The chosen method to produce NPs from PHEA-PLA-PEG2000 was the method based on high-pressure homogenization and subsequent solvent evaporation by adding Pluronic F68 during the process and trehalose before lyophilisation. Obtained colloidal FP-loaded NPs showed a slightly negative surface charge and nanometric d…

Oxidation of pentan-2-ol -Part II: Experimental and modeling study

2021

International audience; The oxidation of pentan-2-ol was investigated at high-pressure in a jet-stirred reactor and in a shock tube. Experiments in the JSR were carried out at 10 atm, between 500-1180 K, for five different equivalence ratios of = 0.35, 0.5, 1, 2, 4 and 1000 ppm of fuel, at a constant residence time of 0.7 s. Reactant, product and intermediate species mole fractions were quantified using Fourier transform infrared spectrometry (FTIR) and gas chromatography (GC). Ignition delay times were measured for pentan-2-ol/O 2 mixtures in argon in a shock tube at 20 and 40 bar, in a temperature range of 1070-1460 K and for equivalence ratios of = 0.5, 1 and 2. Ignition delay times of a…

Dual-broadband rotational CARS modelling of nitrogen at pressures up to 9 MPa. II. Rotational Raman line widths

2002

International audience; Rotational coherent anti-Stokes Raman spectroscopy (CARS) is a well-established spectroscopic technique for thermometry at pre-combustion temperatures an atmospheric pressure. However, at pressures of several MPa, a previous investigation revealed large discrepancies between experimental data and the theoretical model. A re-evaluation has been made of these data (at room temperature and in the range 1.5-9 MPa) with two improvements to the spectral code. The first is the inclusion of an inter-branch interference effect, which is described in detail in Paper I. The second is the use of experimental S-1-branch Raman line widths measured at 295 K, with a temperature depe…

Evaluation of biodegradability on polyaspartamide-polylactic acid based nanoparticles by chemical hydrolysis studies

2015

Here, the synthesis of two graft copolymers based on ?,?-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) and poly(lactic acid) (PLA), the O-(2-aminoethyl)-O'-galactosyl polyethylene glycol (GAL-PEG-NH2) or the methoxypolyethylene glycol amine (H2N-PEG-OCH3) is described. Starting from the obtained PHEA-PLA-PEG-GAL and PHEA-PLA-PEG copolymers, polymeric nanoparticles were prepared by high pressure homogenization-solvent evaporation method. To demonstrate their biodegradability as a function of the matrix composition, a chemical stability study was carried out until 21 days by incubating systems in two media mimicking physiological compartments (pH 7.4 and pH 5.5). The degradability of both nan…

Hepatocyte-targeted fluorescent nanoparticles based on a polyaspartamide for potential theranostic applications

2015

Abstract Here, the synthesis of a galactosylated amphiphilic copolymer bearing rhodamine (RhB) moieties and its use for the preparation of polymeric fluorescent nanoparticles for potential applications in therapy and diagnosis are described. To do this, firstly, a fluorescent derivative of α,β-poly( N -2-hydroxyethyl)- d , l -aspartamide (PHEA) was synthesized by chemical reaction with RhB, and with polylactic acid (PLA), to obtain PHEA-RhB-PLA. Then, the derivatization of PHEA-RhB-PLA with GAL-PEG-NH 2 allows obtaining PHEA-RhB-PLA-PEG-GAL copolymer, with derivatization degrees in -PLA and -PEG-GAL equal to 1.9 mol% and 4.5 mol%, respectively. Starting from this copolymer, liver-targeted f…

In vitrouptake of lysozyme-loaded liposomes coated with chitosan biopolymer as model immunoadjuvants

2009

Chitosan binds to negatively charged soy lecithin liposomes by an electrostatic interaction driven by its cationic amino group. This interaction allows developing stable coated vesicles suitable as a targeted carrier and controlled release system for drugs and vaccines. In this work, we studied the effect of chitosan-coated liposomes on the uptake and antigen presentation of hen egg-white lysozyme (HEL) in Peyer's patches peritoneal macrophages isolated from mice. Chitosan-coated liposomes were characterized according to size, zeta potential, and antigen-loading and release properties. Results showed an increase in the positive net charge and size of the liposomes as the concentration of ch…

CCDC 652752: Experimental Crystal Structure Determination

2009

Related Article: A.Valkonen, M.Lahtinen, J.Tamminen, E.Kolehmainen|2008|J.Mol.Struct.|886|197|doi:10.1016/j.molstruc.2007.11.018

The thiol switch C684 in Mitofusin-2 mediates redox-induced alterations of mitochondrial shape and respiration

2017

Mitofusin-2 (MFN2) is a GTPase in the outer mitochondrial membrane involved in the regulation of mitochondrial fusion and bioenergetics. MFN2 also plays a role in mitochondrial fusion induced by changes in the intracellular redox state. Adding oxidized glutathione (GSSG), the core cellular stress indicator, to mitochondrial preparations stimulates mitochondrial fusion by inducing disulphide bond-mediated oligomer formation of MFN2 and its homolog MFN1 which involve cysteine 684 (C684) of MFN2. Mitochondrial hyperfusion represents an adaptive stress response that confers transient protection by increasing mitochondrial ATP production but how this depends on the thiol switch C684 in MFN2 has …