Efficacy of ethyl ascorbyl ether-containing cosmetic cream on blue light-induced skin changes.

BACKGROUND: Office workers are consistently exposed to blue light, mainly from sunlight and digital device. Recent studies report that blue light has various harmful effects, including cellular changes via reactive oxygen species. Studies on blue light-induced skin changes have only been conducted in vitro and have not been clinically confirmed. OBJECTIVE: We provide novel methods to evaluate the effect of the product on the recovery of skin changed by blue light. METHODS: Internet surveys were conducted for workers in their 20s and 40s regarding exposure time to blue light in various environments. To study the effects of long-term exposure to blue light (456 nm) on the skin, we designed three light intensity conditions, and various skin characteristics were observed. After blue light irradiation, various skin characteristics were analyzed before and after applying ethyl ascorbyl ether (EAE)-containing cosmetic cream for 2 weeks. RESULTS: When exposed to strong blue light for approximately 16 days, the L* value, skin hydration, transparency, and elasticity decreased, and the melanin index, erythema index, a* value, and b* value increased. Furthermore, after short-term blue light irradiation (dose, 269 J/cm2 , the equivalent of blue light exposure for approximately 38 days in daily life), the L* value and elasticity decreased, and the melanin index and erythema index increased. However, when EAE cream was applied on skin for 1-2 weeks, the skin recovered. CONCLUSION: This study clinically confirms the skin changes caused by blue light and the effect of EAE in relieving such changes.

Template-free uniform-sized hollow hydrogel capsules with controlled shell permeation and optical responsiveness.

This study has established a robust and straightforward method for the fabrication of uniform poly(vinylamine) hydrogel capsules without using templates that combines the dispersion polymerization and the sequential hydrolysis/cross-linking. The particle sizes are determined by the degree of cross-linking as well as by the cross-linking reaction time, while the shell thickness is independent of these variables. Diffusion-limited reactions occur at the periphery of the particles, leading to the formation of hydrogel shells with a constant thickness. The treatment of the surfaces of hollow hydrogel capsules with oppositely charged biopolymers limits the permeability through the shell of species even with low molecular weights less than 400 g/mol. Furthermore, we demonstrated that the hydrogel shell phase decorated with Au nanoparticles can be optically ruptured by exposure to laser pulse, a feature that has potential uses in optically responsive drug delivery.

In situ Localization of Molecules in Crosslinked Particles during Electrohydrodynamic Process: Simple Route to Produce Microcapsules and Fibers with Controlled Release.

This study reports a spontaneous selective localization of molecules in crosslinked particles during electrospraying and electrospinning polymer solutions containing the particles. It provides a facile way of preparing microcapsules and fibers with controlled release. The dye molecules were phase separated from the crystalline polymer matrix during the electrohydrodynamic process and moved to the solvent-rich crosslinked particles. The position of the particles in the microcapsules and fibers could be controlled by adjusting compatibility of the particles with the matrix polymer. The microcapsules and fibers did not show the initial burst release of the molecules and gave considerably prolonged release behavior.

Production of uniform-sized polymer core-shell microcapsules by coaxial electrospraying.

Spherical polymeric core-shell microcapsules in uniform size were produced by electrospraying with a coaxial nozzle setup. Contrary to the usual coaxial setup, the inner nozzle was slightly bent to touch the inside wall of the outer nozzle. A polymer solution for the core was introduced through the outer nozzle, and the other solution for the shell was supplied through the inner nozzle. The setup greatly increased reproduction of the same results. As a proof of the concept, core-shell microcapsules consisting of a PS or PMMA core and a PCL shell (PS@PCL, PMMA@PCL) were produced. When the volumetric feed rate of the shell-forming PCL solution was higher than that of the core-forming PS or PMMA solution the core-shell structures in uniform size were readily obtained. In contrast, irregular morphologies were observed when the feed rate of the PCL solution was slower or equal to that of the PS or PMMA solution. The size of the colloid was dependent on the relative feed ratio between the polymer solutions as well as the magnitude of applied voltage.