Vol. 42, No. 1, pp.1-6, 2008Overview of cosmetic dermatological approach for photoaging

In this study, a hydrophobic phospholipid polymer nano-dispersion was formed by self-aggregating poly(2-methacryloyloxyethyl phosphorylcholine-co-stearyl methacrylate) (PMS). Self-aggregation was carried out by diluting a PMS/polyol solution with hot water. The zeta potential of the PMS particles was changed by complexation with anionic or cationic surfactants, the addition of which did not affect the average diameter of the PMS particles, which was always less than 50 nm. The cationized PMS nano-dispersion was used for treating artificially damaged hair. An X-ray photoelectron spectroscopic analysis showed uniform adsorption of the PMS onto the surface of the hair specimens. The PMS nano-dispersion was not only adsorbed on the surface but also permeated into the hair, as shown by a fluorescence microscopic observation of the damaged hair treated with the PMS nano-dispersion that also contained Nile Red. From a scanning electron microscope observation, the PMS was also found to suppress the lift-ups of the hair cuticle. The surface of damaged hair was hydrophilic, whereas the one treated with PMS was hydrophobic, like healthy hair. PMS treatment has decreased the surface friction and electrostatic decay of damaged hair, and also prevented the discoloration of colored hair.
Keywords: 2-methacryloyloxyethyl phosphorylcholine, phospholipid polymer, intercellular lipid, nano-dispersion, self-aggregation, zeta potential, damaged hair, surface friction, electrostatic decay, discoloration