ABSTRACT
Basement membranes are thin structures present in the extracellular matrix that provide a supporting framework on which epithelial and endothelial cells reside. Type IV collagen is present ubiquitously in all basement membranes and plays an important role in cell adhesion, migration differentiation, and growth. These are especially important at the dermoepidermal junction (DEJ) in skin. A reduction in the levels of DEJ proteins occurs in photodamaged skin and especially Type IV collagen at the base of a wrinkle. In these studies, the ability of a triple peptide complex (TPC) to stimulate the production of collagen IV in human skin fibroblasts and its effects on photoaged skin was investigated. Fibroblasts, matured to represent "aged" cells, were stimulated for 72 h with the TPC as well as the three individual peptides constituting the complex, and collagen IV production by the fibroblasts was determined immunochemically. The results show that stimulation with the individual peptides at doses found in 1% (v/v) of the TPC did not result in soluble collagen IV production above levels detected by the non-stimulated cells. However, after stimulation with 1% (v/v) of the TPC, collagen IV was produced by the cells (1.4 ng/ng total protein +/- 0.4 SD, n = 5) when compared to control un-stimulated cells (0.32 ng/ng total protein +/- 0.1 SD, n = 5). This indicates that the combination of the individual peptides is necessary to synergistically stimulate collagen IV production. These findings suggest that the TPC could play a role in the strengthening of the DEJ through its ability to produce collagen IV. In order to determine whether these results translated into significant effects in vivo, we performed two studies. In the first four-week study, a double blind, placebo-controlled and fully randomized clinical study on 22 healthy Caucasian volunteers displaying moderate periorbital wrinkles, a significant reduction in wrinkle parameters determined by profilometry was observed over the 4-week period in comparison to the placebo. This result was reproduced in a 12-week monadic study which also showed improvements in expertly graded wrinkle scores. Collectively, these results effectively demonstrate the anti-aging applications of the TPC.
Subject(s)
Aging , Fibroblasts/physiology , Peptides/pharmacology , Skin Aging/drug effects , Skin Aging/physiology , Adult , Double-Blind Method , Extracellular Matrix Proteins/drug effects , Female , Humans , Male , Middle Aged , Treatment OutcomeABSTRACT
High-resolution ultrasonic spectroscopy was applied to analyse a pseudo-ternary phase diagram for a mixture consisting of water/ethyl oleate/Tween 80 and Span 20 at 25 degrees C. The measured changes in the ultrasonic velocity and attenuation with concentration of water in oil/surfactants mixtures showed several, well defined stages and transitions between them, which allowed construction of an 'ultrasonic' phase diagram. Quantitative analysis of the ultrasonic parameters enabled characterisation of various phases (microemulsion, liquid crystals and pseudo-bicontinuous) as well as evaluation of the state of the water and particle size in microemulsion phase.
Subject(s)
Phase Transition , Spectrum Analysis/methods , Ultrasonics , Chemistry, Pharmaceutical/methods , Emulsions , Hexoses/chemistry , Oleic Acids/chemistry , Particle Size , Polysorbates/chemistry , Surface-Active Agents/chemistry , Water/chemistryABSTRACT
In the present work, high-resolution ultrasonic spectroscopy was applied to analyze a pseudoternary phase diagram for mixtures consisting of water/isopropyl myristate/Epikuron 200 and a cosurfactant (n-propanol). Changes in the ultrasonic velocity and attenuation in the megahertz frequency range were measured in the course of titration of the oil/surfactant/cosurfactant mixture with water at 25 degrees C. The ultrasonic titration profiles showed several phase transitions in the samples, which allowed the construction of an "ultrasonic" phase diagram. Quantitative analysis of the ultrasonic parameters enabled the characterization of various phases (swollen micelles, microemulsion, coarse emulsion, and pseudo-bicontinuous) as well as the evaluation of the state of the water and the particle size. The particle size obtained for the microemulsion region ranged from 5 to 14 nm over the measured concentrations of water/isopropyl myristate/Epikuron 200 and n-propanol, which agreed well with the previous literature data.
