Adipose-Derived Stem Cell Exosomes Promoted Hair Regeneration.

Background: Some scholars have found that dermal papilla spheroid-derived exosomes could promote the development of hair follicles. However, whether adipose-derived stem cell exosomes (ADSC-Exos) have a similar effect on hair growth has not been determined yet. Thus, the purpose of this article was to detect whether ADSC-Exos could promote hair regeneration.

Methods: Adipose-derived stem cells (ADSCs) were isolated from 6-week-old C57BL/6 mice. Then, ADSC-Exos were isolated from the ADSCs. Western blotting was used to detect specific exosome markers. The particle size and distribution of the exosomes were analyzed by NanoSight dynamic light scattering. A total of 12 nude mice were randomly divided into two groups (n = 6 each): the ADSC-Exos group and the control group. For the control group, a mixture of freshly isolated dermal cells (DCs) and epidermal cells (ECs) was grafted. For the ADSC-Exos group, a mixture of DCs, ECs, and 50 μg/ml of ADSC-Exos was grafted. Gross evaluation of the hair regeneration was carried out 2-3 weeks after the transplantation, and the graft site was harvested for histology at the third week.

Results: The existence of exosomes derived from ADSCs was evidenced by CD63, ALX1, and CD9 expression. Two or three weeks after the grafting, the number of regenerated hairs in the ADSC-Exos group was higher than that in the control group (p < 0.001). Histologically, the terminal hairs were remarkable in the ADSC-Exos group, whereas the hair follicles observed in the control group were comparatively immature. The ADSC-Exos group had a higher number of regenerated follicles than the control group (p < 0.001). In addition, we found that the skin tissues in the ADSC-Exos group had higher PDGF and vascular endothelial growth factor expressions and lower transforming growth factor beta 1 levels than those in the control group.

Conclusion: Our results indicated that ADSC-Exos could promote in vivo hair follicle regeneration.