Skin is attractive for drug therapy because it offers an easily accessible route without first-pass metabolism. Transdermal delivery also associated with high patient compliance and through the site of application, can be locally directed. However, to succeed transdermal often required overcome low permeability upper layer skin, stratum corneum (SC). One common strategy employ so-called penetration enhancers that supposedly act increase passage across SC. Still, there a lack understanding...

Abstract Hydration is a key aspect of the skin that influences its physical and mechanical properties. Here, we investigate interplay between molecular macroscopic properties outer layer – stratum corneum (SC) how this varies with hydration. It shown hydration leads to changes in arrangement peptides keratin filaments as well dynamics C-H bond reorientation amino acids protruding terminals protein within SC. The structure occur at threshold corresponding ca. 85% relative humidity (RH)....

The upper layer of our skin, the stratum corneum (SC), is a versatile material that combines mechanical strength with efficient barrier function. In this paper, we discuss these macroscopic properties SC in relation to recent findings on molecular responses and structural diversity protein lipids. We put particular focus intermediate (colloidal) length scale how different substructures are organized respect each other, including effects non-equilibrium conditions skin gradients water other...

In the development of transdermal and topical products it is important to understand how formulation ingredients interact with molecular components upper layer skin, stratum corneum (SC), thereby influence its macroscopic barrier properties. The aim here was investigate effect two commonly used excipients, transcutol dexpanthenol, on as well properties skin membrane. Polarization transfer solid-state NMR methods were combined steady-state flux impedance spectroscopy measurements these common...

Natural moisturizers act to retain the fluidity of molecular components skin barrier under dehydrating conditions – a situation similar hydration.

Mucoadhesion, adhesion of a material to mucous membrane or mucus-covered surface, has been employed in drug delivery prolong contact with adsorption sites and consequently likely improvement absorption. Mucoadhesion the oral cavity also provides additional effects on tactile mouthfeel extended flavor delivery, which impact consumer perception. The mechanisms behind mucoadhesion have not well understood there are contradictory literature results ranking mucoadhesive properties different...

Significance Water evaporation from aqueous solutions of amphiphilic molecules is shown to be independent the driving force, which air relative humidity. This reproduces behavior observed for mammals’ skin outer layer. An homeostatic mechanism achieves control water in systems that adapt their structure content. The response a change humidity operates through thickness self-assembled phase contact with air, and thus permeability this external layer shields rest system variations sets...

Significance Our skin is regularly exposed to solvents in cosmetics, washing and sanitary agents, drug formulations. The uptake of into the may change essential properties skin, for example, its protective barrier function, as well flexibility softness. Herein different relevant formulations products were added samples intact stratum corneum (SC), which outer layer skin. solvent molecules can be tracked inside SC, showing reduced mobility. Furthermore, induce fluidity SC components. These...

Most land-living organisms regularly experience dehydration. In nature, one commonly applied strategy to protect against this osmotic stress is introduce small polar molecules with low vapor pressure, called osmolytes. Two examples of naturally occurring compounds are urea and trimethylamine N-oxide (TMAO), which known have counteracting effects on protein stability. work, we investigate the TMAO lipid self-assembly at varying water contents, focusing dehydrated conditions. By using...

Monoterpenes are abundant in essential oils extracted from plants. These relatively small and hydrophobic molecules have shown important biological functions, including antimicrobial activity membrane penetration enhancement. The interaction between the monoterpenes lipid bilayers is considered to understanding of functions monoterpenes. In this study, we investigated effect cyclic linear on structure dynamics lipids model membranes. We studied ternary system...

Abstract The outer layer of the skin, stratum corneum (SC) is an efficient transport barrier and it tolerates mechanical deformation. At physiological conditions, majority SC lipids are solid, while presence a small amount fluid considered crucial for material properties. Here we use solid-state diffusion nuclear magnetic resonance to characterize composition molecular dynamics lipid fraction in model lipids, focusing on role essential CER EOS, which ceramide esterified omega-hydroxy...

A major challenge to plant growth and survival are changes in temperature diminishing water supply. During acute stress, plants often express stress proteins, such as dehydrins, which intrinsically disordered hydrophilic proteins. In this article, we investigated how the dehydrin Lti30 from Arabidopsis thaliana stabilizes membrane systems that exposed large hydration. We also compared effects of on membranes with those simple osmolytes urea trimethylamine N-oxide. Using X-ray diffraction...

Parkinson's disease is characterized by the aggregation of presynaptic protein α-synuclein (αSyn), and its co-assembly with lipids other cellular matter in brain. Here we investigated lipid-protein a system composed αSyn model membranes containing glycolipid ganglioside GM3. We quantified uptake into co-assembled aggregates how lipid molecular dynamics altered being present co-assemblies using solution 1H- solid-state 13C NMR spectroscopy. Aggregate morphology was studied cryo-TEM. The...

Membranes undergo severe changes under oxidative stress conditions due to the creation of oxidized phospholipid (OxPL) species, which possess molecular properties quite different from their parental lipid components. These OxPLs play crucial roles in various pathological disorders and occurrence is involved onset intrinsic apoptosis, a fundamental pathway programmed mammalian cell death. However, mechanisms by these lipids can exert apoptotic action via host membranes (e.g., altering...

The influence of the co-solutes TMAO, urea, and NaCl on hydration repulsion between lipid membranes is investigated in a combined experimental/simulation approach.

The barrier function of the skin is mainly assured by its outermost layer, stratum corneum (SC). One key aspect in predicting dermal drug delivery and safety assessment exposure to chemicals need determine amount chemical that taken up into SC. We here present a strategy allows for direct measures various solid can be dissolved SC any environmental relative humidity (RH). A main advantage presented method it distinguishes between molecules are within not but might at, example, surface. In...

The outermost layer of the skin is stratum corneum (SC), which mainly comprised solid proteins and lipids. Minor amounts mobile lipids are crucial for macroscopic properties SC, including softness, elasticity barrier function. Still this minor number components not well characterized in terms structure or amount. Conventional quantitative direct polarization (Q-DP) 13C solid-state NMR gives signal amplitudes proportional to concentrations, but fails quantify SC because spectral overlap with...

The barrier function of the skin is mainly assured by its outermost layer, stratum corneum (SC), which consists dead keratin-filled cells embedded in a lipid matrix. daily exposed to an environment with changing conditions terms hydration and different chemicals. Here we investigate how molecule that has reasonable solubility both hydrophobic hydrophilic environments can be directed certain regions SC hydration. We use 1,2,3-trimethoxy propane (TMP) as model substance solid-state NMR on...

The barrier function of the skin mainly relies on its outermost layer, stratum corneum (SC), which is a lipid-protein composite biomaterial. In addition, SC contains mixture small polar compounds, natural moisturizing factor (NMF). Most NMF components are solid at ambient relative humidities (RHs). We herein raise question what effects adding chemicals to as compared single components. use mixtures glucose and NaCl, both present in formulations, were studied using solid-state NMR, wide angle...

We investigate the mechanism responsible for formation of mesoporous silica formed with so-called costructure directing agent (CSDA) route. The synthesis relies on interaction between source (tetraethylorthosilicate), cationic surfactant (C18H37N+(CH3)2(CH2)3N+(CH3)3Br2), and CSDA (carboxyethylsilanetriol), which results in a material functionalized carboxylic groups. Depending concentration HCl synthesis, structure is defined by Fm3̅m (at high pH) Fd3̅m low pH), gradual transition...

Here we show that transport-generated phase separation at the air-liquid interface in systems containing self-assembling amphiphilic molecules and polymers can be controlled by relative humidity (RH) of air. We also our observations described quantitatively with a theoretical model describing interfacial water gradient published previously. These phenomena arises from fact chemical potential corresponding to ambient RH will, general, not match open aqueous solution. This implies...

Abstract The aim of this study is to develop a new in vitro disintegration method for lozenges the oral cavity (OC) by mimicking physiologically relevant conditions OC including saliva flow rate and suction. Disintegration solid-state dosage forms can be employed local absorption or delivering succeeding parts gastrointestinal tract. Understanding important before gaining insight into dissolution absorption. Here abrasion force exerted on lozenge during are controlled texture analyser. We...