LB788 Development of a novel three-dimensional human epidermal model from plucked hair follicle-derived keratinocytes

Three-dimensional (3D) epidermal models reconstructed from human skin-derived keratinocytes have been established and widely used for skin research as an alternative to animal testing, not only in toxicology, but also in skin biology. Because of worldwide expansions of bans and limitations on animal experimentation, such models have been increasingly required. There are currently several reconstructed human epidermis (RHE) models commercially available. They provide reproducible models under controlled conditions, but have a disadvantage that the origin of the keratinocytes is unknown. Therefore, a tailor-made system is needed to investigate the individual differences in RHE derived from each donor. For this, it is possible to make an individual RHE using each donor’s keratinocytes, which are usually derived from skin excision via invasive and uncomfortable procedures for donors. To overcome these drawbacks, we reconstructed RHE using keratinocytes originated from plucked hair follicles as a less-invasive procedure that does not require feeder cells, any serum and matrix proteins. Our model was similar to the standard skin-derived model in morphology, genetic make-up and function, assessed by the staining of differentiation-related proteins, gene array analyses and a skin irritation test recommended by OECD (42 bis protocol), respectively. Therefore, we concluded that this new RHE model from plucked hair follicle-derived keratinocytes is an alternative for conventional skin-derived RHE. We believe that our RHE model provides a useful tool for a less-invasive, safer, and simpler alternative compared with that from skin-derived keratinocytes to investigate individual RHE in normal and disease settings.