Hongyan Zheng

Protection effect of cosmetics on human skin under simulated rigorous environment

Background/purpose: The efficacy of cosmetics on human skin measured under normal mild laboratory environment might be discounted by exterior environment factors such as wind, UV exposure, etc. Few studies have focused on the ‘genuine’ efficacy of cosmetics on human skin during exposure to external rigorous environment. The aim of this study was to develop a model for the evaluation of the efficacy of cosmetics on human skin under simulated rigorous environment.

Moisturizing and antisebum effect of cosmetic application on facial skin

Background  Water content of the stratum corneum and skin surface lipids are important factors in the appearance and function of skin. High water content and low sebum secretion are considered main features of fair skin.

Realtime Cytotoxicity Characterization with Cell-Microelectronic Sensing of Water Soluble Carbon Nanotubes

Continuous cytotoxicity characterization of water-soluble carbon nanotubes (CNTs) was reported using a real time celluar analyzing (RTCA) system. The method, which involved the use of microelectrodes-embedded E-plate microwells seeded with cells, was successfully applied to dynamically monitor three water soluble CNTs cytotoxicity towards mouse 3T3 cells. The results demonstrated that cytotoxicity was caused by exposure to individual CNTs, but bundles and single-walled carbon nanotubes (SWNTs) showed more cytotoxicity with much lower IC50 values than multi-walled carbon nanotubes (MWNTs). Moreover, the cytotoxicity of MWNTs was decreased when MWNTs were modified with L-Lysine (MWNT-Lys). Conventional MTT assay validated the results.