Background: Atopic dermatitis is a common skin disease characterized by a Th2 cell-dominant inflammatory infiltrate, elevated serum IgE levels and impaired epidermal barrier function. It is associated to abnormal epidermal lamellar body secretion, producing alteration in lipid composition and extracellular lamellar membrane organization.
Objectives: The oxazolone-induced atopic dermatitis in hairless mice was used to evaluate in vivo the effect of the application of a lipid system that mimics the morphology, structure and composition of epidermal lamellar bodies.
Background: Many skin diseases are associated with either increases or decreases in lamellar body secretion, or dysfunctional lamellar bodies. Consequently, diseased skin is characterized by reduced barrier function and altered lipid composition and organization. Human skin is commonly evaluated in vivo with non-invasive biophysical techniques.
View Article and Find Full Text PDFAim: In this work the effect of infrared (IR) radiation, at temperatures between 25 and 30°C, on the formation of free radicals (FRs) in the skin is studied. Additionally, the influence of IR radiation at high temperatures in the degradation of skin collagen is evaluated. In both experiments the protective effect against IR radiation of phospholipid nanostructures (bicosomes) incorporating β-carotene (Bcb) is also evaluated.
View Article and Find Full Text PDFEpidermal lamellar bodies (LBs) are organelles that secrete their content, mainly lipids and enzymes, into the intercorneocyte space of the stratum corneum (SC) to form the lamellar structure of this tissue. Thus, LBs have a key role in permeability and the microbial cutaneous barrier. In this work, a complex lipid system that mimics the morphology, structure and composition of LBs has been designed.
View Article and Find Full Text PDFPhospholipid-based nanostructures, bicelles and bicosomes, are proposed as carriers of the antioxidant β-carotene. The stability of these nanostructures and their carotenoid cargo was evaluated in an oxidation environment induced by ultraviolet A, visible and infrared A radiation (UVA-VIS-IRA). Additionally, the effect of these nanoaggregates on non-irradiated and irradiated skin microstructure was studied.
View Article and Find Full Text PDFA rhenium tris-carbonyl derivative (fac-[Re(CO)3Cl(2-(1-dodecyl-1H-1,2,3,triazol-4-yl)-pyridine)]) was incorporated into phospholipid assemblies, called bicosomes, and the penetration of this molecule into skin was monitored using Fourier-transform infrared microspectroscopy (FTIR). To evaluate the capacity of bicosomes to promote the penetration of this derivative, the skin penetration of the Re(CO)3 derivative dissolved in dimethyl sulfoxide (DMSO), a typical enhancer, was also studied. Dynamic light scattering results (DLS) showed an increase in the size of the bicosomes with the incorporation of the Re(CO)3 derivative, and the FTIR microspectroscopy showed that the Re(CO)3 derivative incorporated in bicosomes penetrated deeper into the skin than when dissolved in DMSO.
View Article and Find Full Text PDFHair is exposed every day to a range of harmful effects such as sunlight, pollution, cosmetic treatments, grooming practices and cleansing. The UV components of sunlight damage human hair, causing fibre degradation. UV-B attacks the melanin pigments and the protein fractions (keratin) of hair and UV-A produces free radical/reactive oxygen species (ROS) through the interaction of endogenous photosensitizers.
View Article and Find Full Text PDFSunlight on human hair causes photo-degradation. This results in bleaching due to melanin oxidation through free radicals, and induces keratin impairment. Protein degradation, tryptophan degradation, lipidic peroxidation and electron paramagnetic resonance can be used to evaluate proteic and lipidic photodecomposition and free radical formation in hair fibres subjected to antioxidant action and different UV intensities.
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