Towards the development of a simplified long‐term organ culture method for human scalp skin and its appendages under serum‐free conditions

Abstract

Organ culture of human scalp skin is usually performed with serum-containing medium, which limits its analytical usefulness. Here we report that intact human scalp skin can be grown at the air/liquid interface in supplemented, serum-free William's E medium for more than 2 weeks. Active hair shaft growth was visible until day 16 and was significantly enhanced compared with minimum essential medium (MEM) + 10% fetal bovine serum (FBS). Moreover, William's E medium protected better against cell death than MEM + 10% FBS before day 12. Using quantitative immunochemistry, proliferating (Ki-67+) cells could still be observed in the epithelium of hair follicles even on day 17 of serum-free skin organ culture. The number of apoptotic (TUNEL+) cells in the skin epithelium rose steadily after day 5. Giemsa stains revealed mature skin mast cells even after 13 days in culture. The percentage of surviving hair follicles (mostly with catagen-or telogen-like morphology) gradually increased over time displaying mostly catagen hair follicles after 17 days of culture. Although epidermis and hair follicle epithelium showed increasing atrophy and degeneration, and their pigmentation decreased gradually over time, some long-term-surviving epithelial islands were found in association with remnants of follicular structures as late as on day 88. These preliminary data suggest that a very simple serum-free organ culture method allows prolonged human skin and hair follicle survival as well as some limited hair follicle cycling in intact skin for more than 2 weeks under well-defined experimental conditions. This pragmatic assay invites multiple uses, and may become a valuable tool for both skin and hair research.Key words: hair follicle -hair growth -human scalp skinlong-term organ culture -pigmentation Please cite this paper as: Towards the development of a simplified long-term organ culture method for human scalp skin and its appendages under serumfree conditions. Experimental Dermatology 2007; 16: 37-44.

Phase II Metabolism in Human Skin: Skin Explants Show Full Coverage for Glucuronidation, Sulfation,N-Acetylation, Catechol Methylation, and Glutathione Conjugation

“…Skin thickness varied based on anatomic region and individual characteristics of the donor (,1 mm for eyelids, 1-2 mm for breast and inguinal, 2-5 mm for abdomen and thigh skin). Cylindrical skin explants, 4 mm in diameter (12.5 mm 2 ), were prepared with a sterile biopsy tool and immediately placed in prewarmed Williams' E medium supplemented with insulin (10 mg·ml -1 ), hydrocortisone (10 ng·ml -1 ), and penicillin-streptomycinglutamine (100 U·ml -1 of penicillin; 100 mg·ml -1 of streptomycin; 2 mM L-glutamine) (Lu et al, 2007). Medium pH value was 7.4, culturing temperature was 37°C, incubator humidity was 90%, and CO 2 content was 5%.…”

Endocannabinoids limit excessive mast cell maturation and activation in human skin

“…in atopic (HFs), the follicular connective tissue sheath (CTS) 10,11 . Therefore, we 138 hypothesized that robust mechanisms must be in place to avoid excessive angiogenesis, wound healing and hair growth 8,10,12 . Moreover, the maturation …”

“…[8][9][10][11] . HFs were first incubated overnight to adapt to culture conditions 755 after which the medium was replaced and vehicle or test substances was added.…”

Hair Follicle Reconstruction and Stem Cells

“…Even in optimized conditions, HFs begin to degenerate after 20 days in culture, on average, while apoptotic cells appear approximately on day 5 [86]. HFs maintained in vitro are unable to keep cycling [87,88].…”