scholarly journals INTERACTION OF NANOSTRUCTURED LIPID CARRIERS WITH HUMAN MEIBUM

2019 ◽  
pp. 35-42
Author(s):  
Pattravee Niamprem ◽  
Thomas J. Milla ◽  
Burkhardt S. Schuett ◽  
S. P. Srinivas ◽  
Waree Tiyaboonchai
Keyword(s):  
Particle Size ◽  
Surface Pressure ◽  
Tear Film ◽  
Nanostructured Lipid Carriers ◽  
Langmuir Trough ◽  
Surface Activities ◽  
Lipid Films ◽  
Pressure Area ◽  
Surface Active ◽  
High Pressure Homogenizer

Objective: This study aimed to determine the possibility of nanostructured lipid carriers (NLCs) as a bionic tear film by determining the surface activities of the developed NLCs and their interaction with human meibomian lipid films. Methods: NLCs with different types of solid lipids and surfactants were prepared by a high-pressure homogenizer. The particle size was determined by dynamic light scattering. The surface activities of the NLCs and NLCs mixed with meibomian lipids were measured using a Langmuir trough and the resulting surface pressure area (Π-A) profiles were compared. These lipid films were further analyzed using fluorescence microscopy and scanning electron microscopy (SEM). Results: The particle size of prepared NLCs varied from 38–280 nm based on types of solid lipid and surfactant. All NLCs were highly surface active as indicated by their maximum surface pressure (Πmax). The Π-A profiles of meibum seeded with NLCs showed higher surface pressure than meibum alone and the shape of profiles were dominated by the meibomian lipids. These findings were in agreement with fluorescence and SEM micrographs, which revealed that the NLCs could adsorb and integrate to the meibomian lipid films as well as diffuse from the subphase to the lipid films. Conclusion: NLCs are surface active and can integrate with meibomian lipid films formed stable films. The type of interaction can be tailored by altering the solid lipids used in the formulation of the NLCs which could provide the means to develop efficient formulations for targeting dry eye disease related to a non-functional tear film lipid layer.

Synthese und Eigenschaften von Lipoaminosäuren und Lipodipeptiden des Ornithins / Synthesis and Properties of Lipo Amino Acids and Lipodipeptides of Ornithine

1991 ◽  
Vol 46 (8) ◽  
pp. 1098-1104 ◽  
Author(s):  
Gerhard Kellner ◽  
Manfred Liefländer
Keyword(s):  
Amino Acids ◽  
Surface Pressure ◽  
Amino Group ◽  
Carboxylic Group ◽  
Langmuir Trough ◽  
Monomolecular Films ◽  
Pressure Area

Lipo amino acids and α- as well as δ-connected lipodipeptides of ornithine were synthesized. The lipid portion was introduced to the amino group by acylating with hexadecanoyl chloride and to the carboxylic group by amidating with hexadecylamine or octadecylamine, respectively. Due to their amphiphilic properties these compounds were measured in a LANGMUIR-trough and thus their ability to form monomolecular films was examined. Dates from the surface pressure - area isotherms are listed in the following composition.

Effect of grain size on the vapour phase hydration of monoclinic and triclinic modifications of tricalcium silicate; role of high temperature activation

1991 ◽  
Vol 56 (10) ◽  
pp. 1993-2008
Author(s):  
S. Hanafi ◽  
G. M. S. El-Shafei ◽  
B. Abd El-Hamid
Keyword(s):  
Particle Size ◽  
Vapour Phase ◽  
Tricalcium Silicate ◽  
Active Centers ◽  
Thermally Activated ◽  
Grain Sizes ◽  
Intermediate Size ◽  
Surface Active ◽  
Temperature Activation

The hydration of tricalcium silicate (C3S) with three grain sizes of monoclinic (M) and triclinic (T) modifications and on their thermally activated samples were investigated by exposure to water vapour at 80°C for 60 days. The products were investigated by XRD, TG and N2 adsorption. The smaller the particle size the greater was the hydration for both dried and activated samples from (M). In the activated samples a hydrate with 2θ values of 38.4°, 44.6° and 48.6° could be identified. Hydration increased with particle size for the unactivated (T) samples but after activation the intermediate size exhibited enhanced hydration. Thermal treatment at 950°C of (T) samples increased the surface active centers on the expense of those in the bulk. Changes produced in surface texture upon activation and/or hydration are discussed.

scholarly journals Characterization of Astaxanthin Nanoemulsions Produced by Intense Fluid Shear through a Self-Throttling Nanometer Range Annular Orifice Valve-Based High-Pressure Homogenizer

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2856
Author(s):  
Gary B. Smejkal ◽  
Edmund Y. Ting ◽  
Karthik Nambi Arul Nambi ◽  
Richard T. Schumacher ◽  
Alexander V. Lazarev
Keyword(s):  
Particle Size ◽  
Size Reduction ◽  
Hydrodynamic Diameter ◽  
Fluid Shear ◽  
Particle Size Reduction ◽  
Annular Gap ◽  
Oil In Water ◽  
High Pressure Homogenizer ◽  
Pass Through

Stable, oil-in-water nanoemulsions containing astaxanthin (AsX) were produced by intense fluid shear forces resulting from pumping a coarse reagent emulsion through a self-throttling annular gap valve at 300 MPa. Compared to crude emulsions prepared by conventional homogenization, a size reduction of over two orders of magnitude was observed for AsX-encapsulated oil droplets following just one pass through the annular valve. In krill oil formulations, the mean hydrodynamic diameter of lipid particles was reduced to 60 nm after only two passes through the valve and reached a minimal size of 24 nm after eight passes. Repeated processing of samples through the valve progressively decreased lipid particle size, with an inflection in the rate of particle size reduction generally observed after 2–4 passes. Krill- and argan oil-based nanoemulsions were produced using an Ultra Shear Technology™ (UST™) approach and characterized in terms of their small particle size, low polydispersity, and stability.

Molecular Organization of Nonlinear Organic Films Laminated by Langmuir-Blodgett Method

2005 ◽  
Vol 492-493 ◽  
pp. 115-122 ◽  
Author(s):  
Saburo Uchida ◽  
Vijay T. Chitnis ◽  
Hideo Furuhashi ◽  
Toshio Yoshikawa ◽  
Akinori Maeda ◽  
...  
Keyword(s):  
Surface Pressure ◽  
Nonlinear Optical ◽  
Epitaxial Films ◽  
Operating Conditions ◽  
Molecular Organization ◽  
Optimum Operating ◽  
Monolayer Formation ◽  
Langmuir Blodgett ◽  
Molecular Arrangement ◽  
Pressure Area

In the 21st century, the optical computation is likely to be the basic technology for processing lots of information at high speed. The aim of the present research work is to develop optical logic gates or memory chips. For this purpose, we have examined the suitability of organic nonlinear optical dye material Vanadyl-phthalocyanine (VOPc). Large single crystals of this material have been fabricated by using Molecular Beam Epitaxy (MBE) technique. The epitaxial films were formed on the substrate under optimum operating conditions. However, the epitixial growth is observed only up to a limited thickness. Above this thickness, the films become non-epitaxial, which can be improved by annealing. The reformation of the epitaxial films has been confirmed. We have also reported the effects of the environment of high temperature on the multilayered tetra-tert-butyl-Vanadyl-phthalocyanine ((t-bu)4VOPc) films, formed by Langmuir-Blodgett (LB) method. The solvent used to dissolve ((t-bu)4VOPc) was 1,2-dichloroethane. The monolayer on the surface of the water was transferred to a glass substrate by the vertical dipping method. If the multilayered stack is too thick, the molecular arrangement of the film may get disturbed. The improvement in the molecular arrangement of the LB films was examined and confirmed by measuring it’s nonlinear optical susceptibility, using Maker Fringe Method. Monolayer formation on water surface depends on the surface pressure-area isotherm. If this monolayer formation is not perfect, multiplayer stacks cannot be formed. The molecular films were aligned almost perpendicular to the substrate, as estimated from the limiting molecular area of surface pressure-area isotherm. The molecular organization of the monolayer on the substrate and the molecular structure of the multilayered ((t-bu)4VOPc) films are discussed.

scholarly journals Development of Solid Lipid Nanoparticles and Nanostructured Lipid Carriers of Loteprednol Etabonate: Physicochemical Characterization and Ex Vivo Permeation Studies

2021 ◽  
Author(s):  
Burcu Üner ◽  
Samet Özdemir ◽  
Çetin Taş ◽  
Yıldız Özsoy ◽  
Melike Üner
Keyword(s):  
Particle Size ◽  
Solid Lipid Nanoparticles ◽  
Drug Loading ◽  
Physicochemical Characterization ◽  
Lipid Nanoparticles ◽  
Nanostructured Lipid Carriers ◽  
Fickian Diffusion ◽  
Control Group ◽  
Loteprednol Etabonate ◽  
Solid Lipid

Abstract Purpose Loteprednol etabonate (LE) is a new generation corticosteroid that is used for the treatment of inflammatory and allergic conditions of the eye, and management of seasonal allergic rhinitis nasally. LE which is a poorly soluble drug with insufficient bioavailability, has a high binding affinity to steroid receptors. Sophisticated colloidal drug delivery systems of LE could present an alternative for treatment of inflammatory and allergic conditions of the skin. For this purpose, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were attempted to improve for transdermal LE delivery for the first time. Methods SLN and NLC were produced by hot homogenization and ultrasonication technique. Formulations were characterized by dynamic light scattering, scanning electron microscopy, fourier transform infrared spectroscopy and differential scanning calorimetry. Their physical stability was monitored for 3 months of storage. Drug release profiles and permeation properties of SLN and NLC through the porcine skin were investigated. Results It was determined that SLN and NLC below 150 nm particle size had a homogeneous particle size distribution as well as high drug loading capacities. They were found to be stable both physically and chemically at room temperature for 90 days. In terms of release kinetics, it was determined that they released from SLN and NLC in accordance with Fickian diffusion release. Formulations prepared in this study were seen to significantly increase drug penetration through pig skin compared to the control group (p ≤ 0.05). Conclusion SLN and NLC formulations of LE can be stated among the systems that can be an alternative to conventional systems with less side-effect profile in the treatment of inflammatory problems on the skin.

scholarly journals Condensation of Model Lipid Films by Cholesterol: Specific Ion Effects

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 474
Author(s):  
Alberto Martín-Molina ◽  
Teresa Del Castillo-Santaella ◽  
Yan Yang ◽  
Julia Maldonado-Valderrama
Keyword(s):  
Milk Fat ◽  
Food Systems ◽  
Mechanical Resistance ◽  
Brewster Angle Microscopy ◽  
Lipid Films ◽  
Pressure Area ◽  
Milk Fat Globule ◽  
Combined Action ◽  
Fat Globule ◽  
Ion Effects

The condensing effect and the ability of cholesterol (CHOL) to induce ordering in lipid films is a question of relevance in biological membranes such as the milk fat globule membrane (MFGM) in which the amount of CHOL influences the phase separation and mechanical resistance to rupture of coexisting phases relevant to emulsified food systems. Here, we study the effect of different salts (NaCl, CaCl2, MgCl2, LaCl3) on monolayers made of a model mixture of lipids (DPPC:DPPS 4:1) and CHOL. To this end, we apply Langmuir Film Balance to report a combined analysis of surface pressure-area (π-A) and surface potential-area (ΔV–A) isotherms along with Micro-Brewster Angle Microscopy (Micro-BAM) images of the monolayers in the presence of the different electrolytes. We show that the condensation of lipid by CHOL depends strongly on the nature of the ions by altering the shape and features of the π-A isotherms. ΔV–A isotherms provide further detail on the ion specific interactions with CHOL. Our results show that the condensation of lipids in the presence of CHOL depends on the combined action of ions and CHOL, which can alter the physical state of the monolayer.

scholarly journals Ice-nucleating ability of aerosol particles and possible sources at three coastal marine sites

2018 ◽  
Vol 18 (21) ◽  
pp. 15669-15685 ◽  
Author(s):  
Meng Si ◽  
Victoria E. Irish ◽  
Ryan H. Mason ◽  
Jesús Vergara-Temprado ◽  
Sarah J. Hanna ◽  
...  
Keyword(s):  
Particle Size ◽  
Aerosol Particles ◽  
Freezing Temperature ◽  
The Arctic ◽  
Labrador Sea ◽  
Sea Spray ◽  
Site Density ◽  
Coastal Marine ◽  
Surface Active ◽  
Surface Area Basis

Abstract. Despite the importance of ice-nucleating particles (INPs) for climate and precipitation, our understanding of these particles is far from complete. Here, we investigated INPs at three coastal marine sites in Canada, two at mid-latitude (Amphitrite Point and Labrador Sea) and one in the Arctic (Lancaster Sound). For Amphitrite Point, 23 sets of samples were analyzed, and for Labrador Sea and Lancaster Sound, one set of samples was analyzed for each location. At all three sites, the ice-nucleating ability on a per number basis (expressed as the fraction of aerosol particles acting as an INP) was strongly dependent on the particle size. For example, at diameters of around 0.2 µm, approximately 1 in 106 particles acted as an INP at −25 ∘C, while at diameters of around 8 µm, approximately 1 in 10 particles acted as an INP at −25 ∘C. The ice-nucleating ability on a per surface-area basis (expressed as the surface active site density, ns) was also dependent on the particle size, with larger particles being more efficient at nucleating ice. The ns values of supermicron particles at Amphitrite Point and Labrador Sea were larger than previously measured ns values of sea spray aerosols, suggesting that sea spray aerosols were not a major contributor to the supermicron INP population at these two sites. Consistent with this observation, a global model of INP concentrations under-predicted the INP concentrations when assuming only marine organics as INPs. On the other hand, assuming only K-feldspar as INPs, the same model was able to reproduce the measurements at a freezing temperature of −25 ∘C, but under-predicted INP concentrations at −15 ∘C, suggesting that the model is missing a source of INPs active at a freezing temperature of −15 ∘C.

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