Bioengineering a 3D integumentary organ system from iPS cells using an in vivo transplantation model.

The integumentary organ system is a complex system that plays important roles in waterproofing, cushioning, protecting deeper tissues, excreting waste, and thermoregulation. We developed a novel in vivo transplantation model designated as a clustering-dependent embryoid body transplantation method and generated a bioengineered three-dimensional (3D) integumentary organ system, including appendage organs such as hair follicles and sebaceous glands, from induced pluripotent stem cells. This bioengineered 3D integumentary organ system was fully functional following transplantation into nude mice and could be properly connected to surrounding host tissues, such as the epidermis, arrector pili muscles, and nerve fibers, without tumorigenesis. The bioengineered hair follicles in the 3D integumentary organ system also showed proper hair eruption and hair cycles, including the rearrangement of follicular stem cells and their niches. Potential applications of the 3D integumentary organ system include an in vitro assay system, an animal model alternative, and a bioengineered organ replacement therapy.

Five-year efficacy of finasteride in 801 Japanese men with androgenetic alopecia.

Finasteride is standard medical treatment for androgenetic alopecia; however, no large studies with 5 years or more of follow up have been performed in Japan. The authors followed Japanese men with androgenetic alopecia treated with finasteride for 5 years to evaluate long-term treatment efficacy. Of 903 men treated with finasteride (1 mg/day), 801 patients were evaluated over 5 years by modified global photographic assessment. Although the proportion of improvement was high (99.4%), modified global photographic assessment scores after 5 years of treatment were lower in patients with more advanced disease as measured by the modified Norwood-Hamilton scale. After separating patients into "sufficient" and "insufficient" efficacy groups according to the modified global photographic assessment score after 5 years (scores ≥6 and <6, respectively), multivariate analysis showed that independent risk factors of insufficient efficacy were age at start of treatment of 40 years or more (P = 0.021) and classification on the modified Norwood-Hamilton scale (P < 0.001), whereas presence of stress at start of treatment was a negative predictor (P = 0.025). In conclusion, continuous finasteride treatment for 5 years improved androgenetic alopecia with sustained effect among Japanese. Younger age and less advanced disease at start of treatment were the key predictors of higher finasteride efficacy.