J Biotechnol. 2011 Jan 27.
De novo formation and ultra-structural characterization of a fiber-producing human hair follicle equivalent in vitro.
Lindner G, Horland R, Wagner I, Ata B, Lauster R.
Department of Biotechnology, Technische Universität Berlin, Ackerstr.71-76, D-13355 Berlin, Germany.
Across many tissues and organs, the ability to create an organoid, the smallest functional unit of an organ, in vitro is the key both to tissue engineering and preclinical testing regimes. The hair follicle is an organoid that has been much studied based on its ability to grow quickly and to regenerate after trauma. But hair follicle formation in vitro has been elusive. Treating hair loss due to pattern baldness or alopecia areata including that induced by chemotherapy, remains a significant unmet medical need. By carefully analyzing and recapitulating the growth conditions of hair follicle formation, we recreated human hair follicles in tissue culture that were capable of producing hair. Our microfollicles contained all relevant cell types and their structure and orientation resembled in some ways excised hair follicle specimens from human skin. This finding offers a new window onto hair follicle development. Having a robust culture system for hair follicles is an important step towards improved hair regrowth as well as to an understanding of how marketed drugs or drug candidates, including cancer chemotherapy, will affect this important organ.
Dermatol Online J. 2010;16:3.
Does D matter? The role of vitamin D in hair disorders and hair follicle cycling.
Amor KT, Rashid RM, Mirmirani P.
"...Limited studies have been done in humans to elaborate the role of vitamin D in the hair cycle. A potential application for vitamin D is in chemotherapy-induced hair loss. Topical calcitriol has been shown to protect against chemotherapy-induced alopecia caused by paclitaxel and cyclophosphamide. However, topical calcitriol failed to protect against chemotherapy-induced hair loss caused by a combination of 5-fluorouracil, doxorubicin, and cyclophosphamide and a combination of cyclophosphamide, methotrexate, and 5-fluorouracil [36, 37]. The ability of topical calcitriol to prevent chemotherapy-induced alopecia may therefore depend on the chemotherapy agents used. Of note, the studies in which no effects were observed, were small and may have used doses of vitamin D that were inadequate to protect against chemotherapy-induced hair loss. The more potent vitamin D3 analogs used on mice by Vegesna et al. have yet to be evaluated in humans.
Another potential application for vitamin D is in hair loss due to scalp psoriasis, which is associated with an increased telogen to anagen ratio. Although vitamin D3 analogs have been used in combination or as an alternative to topical steroids to treat scalp psoriasis for many years, their ability to combat the associated hair loss has not been thoroughly evaluated. A placebo-controlled trial with 26 patients showed that calcipotriol did not affect the telogen to anagen ratio after 6 weeks of treatment, but the optimal effect of calcipotriol on scalp psoriasis is not seen until 8 weeks. Thus, the follow up may have been too brief to detect an effect of calcipotriol on hair loss.
It has been suggested that an optimal concentration of vitamin D is necessary to delay the aging phenomena, including hair loss. A cross sectional study of 296 healthy men was done to determine the association, if any, between male pattern baldness and serum 25-hydroxyvitamin D levels. Based on this study, the extent and severity of male pattern baldness does not appear to be associated with serum 25-hydroxyvitamin D levels . Additional studies in subjects with age-related or senescent hair thinning as well as in women with female pattern hair loss could be considered to see if there is an association of hair loss with serum 25-hydroxyvitamin D levels.
Because it is known that the absence of VDR leads to hair loss, it was hypothesized that there may be VDR gene polymorphisms (Bsml, Apal, and Taql) in patients with alopecia areata. A study of VDR genotypes in 32 patients with alopecia areata and 27 controls showed no association between these VDR gene polymorphisms and alopecia areata. A separate study also showed that there was no relationship between the VDR gene FokI polymorphism and alopecia areata......
edited for hair loss blog
Dr Proctor's organic semiconductor device.