scholarly journals Effect of Molecular Composition of Head Group and Temperature on Micellar Properties of Ionic Surfactants with C12 Alkyl Chain

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 651 ◽  
Author(s):  
Jarmila Oremusová ◽  
Zuzana Vitková ◽  
Anton Vitko ◽  
Marián Tárník ◽  
Eva Miklovičová ◽  
...  
Keyword(s):  
Thermodynamic Parameters ◽  
Dosage Forms ◽  
Sodium Sulphate ◽  
Ionic Surfactants ◽  
Head Group ◽  
Optimal Dosage ◽  
Trimethylammonium Chloride ◽  
Counterion Binding ◽  
Micellar Properties ◽  
The Impact

The paper analyses influences of the temperature and hydrophilic groups on micellar properties of ionic surfactants with 12-carbonic hydrophobic chains. The aim is to assess the impact of hydrophilic groups and temperature on thermodynamic parameters and micellization. This knowledge is indispensable for the formulation of new dosage forms. The method uses conductometric measurements. The following hydrophilic groups are analyzed: trimethylammonium bromide, trimethylammonium chloride, ethyldimethylammonium bromide, didodecyldimethylammonium bromide, pyridinium chloride, benzyldimethyl-ammonium chloride, methylephedrinium bromide, cis and trans-[(2-benzyloxy)-cyclohexyl-methyl]-N, N-dimethylammonium bromide, sodium sulphate and lithium sulphate. Except for a few cases, there is a good agreement between values of critical micellar concentrations (CMC) and critical vesicle concentration (CVC) obtained here and those which were obtained by other authors and/or by other physicochemical methods. Values of the CMC are compared with respect to the molar masses of hydrophilic groups. It was found that CMC values increased non-linearly with increasing system temperature. The degrees of counterion binding and thermodynamic parameters, like the standard molar Gibbs energy, enthalpy and entropy of micellization are determined and discussed in detail. The results obtained will be incorporated into in silico processes of modeling and design of optimal dosage forms, a current interdisciplinary research focus of the team.

scholarly journals Titanium Dioxide Presents a Different Profile in Dextran Sodium Sulphate-Induced Experimental Colitis in Mice Lacking the IBD Risk Gene Ptpn2 in Myeloid Cells

2021 ◽  
Vol 22 (2) ◽  
pp. 772
Author(s):  
Javier Conde ◽  
Marlene Schwarzfischer ◽  
Egle Katkeviciute ◽  
Janine Häfliger ◽  
Anna Niechcial ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Titanium Dioxide ◽  
Genetic Risk ◽  
Intestinal Inflammation ◽  
Sodium Sulphate ◽  
Food Additive ◽  
Wild Type ◽  
Dextran Sodium Sulphate ◽  
Risk Gene ◽  
The Impact

Environmental and genetic factors have been demonstrated to contribute to the development of inflammatory bowel disease (IBD). Recent studies suggested that the food additive; titanium dioxide (TiO2) might play a causative role in the disease. Therefore, in the present study we aimed to explore the interaction between the food additive TiO2 and the well-characterized IBD risk gene protein tyrosine phosphatase non-receptor type 2 (Ptpn2) and their role in the development of intestinal inflammation. Dextran sodium sulphate (DSS)-induced acute colitis was performed in mice lacking the expression of Ptpn2 in myeloid cells (Ptpn2LysMCre) or their wild type littermates (Ptpn2fl/fl) and exposed to the microparticle TiO2. The impact of Ptpn2 on TiO2 signalling pathways and TiO2-induced IL-1β and IL-10 levels were studied using bone marrow-derived macrophages (BMDMs). Ptpn2LysMCre exposed to TiO2 exhibited more severe intestinal inflammation than their wild type counterparts. This effect was likely due to the impact of TiO2 on the differentiation of intestinal macrophages, suppressing the number of anti-inflammatory macrophages in Ptpn2 deficient mice. Moreover, we also found that TiO2 was able to induce the secretion of IL-1β via mitogen-activated proteins kinases (MAPKs) and to repress the expression of IL-10 in bone marrow-derived macrophages via MAPK-independent pathways. This is the first evidence of the cooperation between the genetic risk factor Ptpn2 and the environmental factor TiO2 in the regulation of intestinal inflammation. The results presented here suggest that the ingestion of certain industrial compounds should be taken into account, especially in individuals with increased genetic risk

The main reasons for substance formation and natural process manifestation

2021 ◽  
pp. 76-96
Author(s):  
Alexander Likhachev
Keyword(s):  
Thermodynamic Parameters ◽  
World History ◽  
Natural Process ◽  
Natural Materials ◽  
Main Factors ◽  
Composition Structure ◽  
The Impact ◽  
Insight Into ◽  
Structure Properties

Natural materials and processes represent the global substance reflecting and determining its formation and existence as a whole and in all its components. Revealing the reasons for their formation and manifestation is crucial. The paper highlights the two main factors: «influences» and «gradients». Influences are interpreted as the impact of some substances and events on other similar parameters, and gradients are vector changes and differences in systems composition, structure, properties, states, energy and thermodynamic parameters. To provide an insight into the role and significance of the above factors and reasons, an attempt was made to consider their potential manifestation throughout the general world history within the existing knowledge about it.

Ionic-liquid-based surfactants with unsaturated head group: synthesis and micellar properties of 1-(n-alkyl)-3-vinylimidazolium bromides

2015 ◽  
Vol 293 (11) ◽  
pp. 3213-3224 ◽  
Author(s):  
Naved I. Malek ◽  
Zuber S. Vaid ◽  
Utkarsh U. More ◽  
Omar A. El Seoud
Keyword(s):  
Ionic Liquid ◽  
Head Group ◽  
Micellar Properties

scholarly journals Structural Characterization of Natural Yeast Phosphatidylcholine and Bacterial Phosphatidylglycerol Lipid Multilayers by Neutron Diffraction

2021 ◽  
Vol 9 ◽  
Author(s):  
Alessandra Luchini ◽  
Giacomo Corucci ◽  
Krishna Chaithanya Batchu ◽  
Valerie Laux ◽  
Michael Haertlein ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Acyl Chain ◽  
Model Systems ◽  
Head Group ◽  
Single Class ◽  
Lipid Mixtures ◽  
Chain Composition ◽  
Acyl Chain Composition ◽  
The Impact

Eukaryotic and prokaryotic cell membranes are difficult to characterize directly with biophysical methods. Membrane model systems, that include fewer molecular species, are therefore often used to reproduce their fundamental chemical and physical properties. In this context, natural lipid mixtures directly extracted from cells are a valuable resource to produce advanced models of biological membranes for biophysical investigations and for the development of drug testing platforms. In this study we focused on single phospholipid classes, i.e. Pichia pastoris phosphatidylcholine (PC) and Escherichia coli phosphatidylglycerol (PG) lipids. These lipids were characterized by a different distribution of their respective acyl chain lengths and number of unsaturations. We produced both hydrogenous and deuterated lipid mixtures. Neutron diffraction experiments at different relative humidities were performed to characterize multilayers from these lipids and investigate the impact of the acyl chain composition on the structural organization. The novelty of this work resides in the use of natural extracts with a single class head-group and a mixture of chain compositions coming from yeast or bacterial cells. The characterization of the PC and PG multilayers showed that, as a consequence of the heterogeneity of their acyl chain composition, different lamellar phases are formed.

scholarly journals The Impact of the Nocturnal Transition on the Lifetime and Evolution of Supercell Thunderstorms in the Great Plains

2018 ◽  
Vol 33 (4) ◽  
pp. 1045-1061 ◽  
Author(s):  
Matthew E. Gropp ◽  
Casey E. Davenport
Keyword(s):  
Thermodynamic Parameters ◽  
Great Plains ◽  
Environmental Changes ◽  
Kinematic Parameters ◽  
Storm Evolution ◽  
Composite Parameter ◽  
Convective Inhibition ◽  
Supercell Thunderstorms ◽  
Parameter Values ◽  
The Impact

Abstract Predicting the evolution of supercell thunderstorms during and after the evening transition is a known challenge due to an incomplete understanding of how these events evolve in response to associated environmental changes. To quantify the connection between storm evolution and environmental changes during the nocturnal transition, 157 initially isolated Great Plains supercell thunderstorms occurring between 2005 and 2016 are examined. Each supercell is categorized as either maintained, dissipating, growing upscale, or merging. Changes in the inflow environment are quantified using hourly RUC and RAP model proximity soundings between 1 h prior to local sunset time and 5 h postsunset. Using these soundings, numerous thermodynamic and kinematic parameters are derived, and distributions of these parameter values are statistically compared among the evolution categories. It was found that each evolution classification existed in a unique set of kinematic and thermodynamic parameters; this distinction was most evident when comparing maintained and dissipation categories. In particular, storm-relative helicity, most unstable convective inhibition (MUCIN), and associated composite parameters were best able to distinguish supercell evolution. Notably, maintained supercells were characterized by significant increases in storm-relative helicity and comparatively smaller increases in the magnitude of MUCIN during the nocturnal transition; together, these parameters promote a sustained and robust rotating updraft. A convective inhibition–scaled supercell composite parameter is proposed to further assist in predicting supercell maintenance during the nocturnal transition.

scholarly journals Embedded 3D Printing of Novel Bespoke Soft Dosage Form Concept for Pediatrics

Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 630 ◽  
Author(s):  
Katarzyna Rycerz ◽  
Krzysztof Adam Stepien ◽  
Marta Czapiewska ◽  
Basel T. Arafat ◽  
Rober Habashy ◽  
...  
Keyword(s):  
Dosage Form ◽  
Drug Loading ◽  
Three Dimensional ◽  
Dosage Forms ◽  
Dose Titration ◽  
Step Method ◽  
Needle Size ◽  
Model Drug ◽  
Semi Solid ◽  
The Impact

Embedded three-dimensional printing (e-3DP) is an emerging method for additive manufacturing where semi-solid materials are extruded within a solidifying liquid matrix. Here, we present the first example of employing e-3DP in the pharmaceutical field and demonstrate the fabrication of bespoke chewable dosage forms with dual drug loading for potential use in pediatrics. LegoTM-like chewable bricks made of edible soft material (gelatin-based matrix) were produced by directly extruding novel printing patterns of model drug ink (embedded phase) into a liquid gelatin-based matrix (embedding phase) at an elevated temperature (70 °C) to then solidify at room temperature. Dose titration of the two model drugs (paracetamol and ibuprofen) was possible by using specially designed printing patterns of the embedded phase to produce varying doses. A linearity [R2 = 0.9804 (paracetamol) and 0.9976 (ibuprofen)] was achieved between percentage of completion of printing patterns and achieved doses using a multi-step method. The impact of embedded phase rheological behavior, the printing speed and the needle size of the embedded phase were examined. Owning to their appearance, modular nature, ease of personalizing dose and geometry, and tailoring and potential inclusion of various materials, this new dosage form concept holds a substantial promise for novel dosage forms in pediatrics.

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