The empowering influence of air-liquid interface culture on skin organoid hair follicle development.

BACKGROUND: Rodent models have been widely used to investigate skin development, but do not account for significant differences in composition compared to human skin. On the other hand, two-dimensional and three-dimensional engineered skin models still lack the complex features of human skin such as appendages and pigmentation. Recently, hair follicle containing skin organoids (SKOs) with a stratified epidermis, and dermis layer have been generated as floating spheres from human-induced pluripotent stem cells (hiPSCs). METHODS: The current study aims to investigate the generation of hiPSCs-derived SKOs using an air-liquid interface (ALI) model on transwell membranes (T-SKOs) and compares their development with conventional floating culture in low-attachment plates (F-SKOs). RESULTS: Mature SKOs containing an epidermis, dermis, and appendages are created in both T-SKO and F-SKO conditions. It was found that the hair follicles are smaller and shorter in the F-SKO compared with T-SKOs. Additionally, the ALI conditions contribute to enhanced hair follicle numbers than conventional floating culture. CONCLUSIONS: Together, this study demonstrates the significant influence of transwell culture on the morphogenesis of hair follicles within SKOs and highlights the potential for refinement of skin model engineering for advancing dermatology and skin research.