A Novel Regenerative Medicine Approach for Hair Restoration

Chaffoo, Richard

Goals/Purpose
:

De Novo Hair Follicle Generation

Antonella Pinto, PhD

1

; Alexey V. Terskikh, PhD

1

2

1

Stemson Therapeutics, San Diego, CA;

2

La Jolla Plastic Surgery & Dermatology, La Jolla,

CA, USA

Goals/Purpose

Alopecia is a dermatologic condition that affects the pilosebaceous unit in both women and men, and

while it can occur anywhere on the body, it most commonly affects the scalp. The most widespread

form of hair loss is androgenic alopecia which affects more than 50 million men and 30 million women

within the United States. Other types of hair loss include those initiated from medication, scarring, or

autoimmune conditions. Medications such as Minoxidil (Rogaine) or Finasteride (Propecia) are

commonly prescribed to encourage new growth or slow the rate of hair loss, respectively. For patients

that do not respond to medications, hair transplantaton surgery may be suitable. However, since it

utilizes existing hair as donor follicles, it is not effective for treating those with widespread thinning and

baldness. Although alopecia is a benign disorder, even the most negligible amount of hair loss can be

devastating to a patient's self-esteem, self-image, and overall quality of life.

The goal of this research is to provide a solution to hair loss for those patients that neither respond to

medications nor are good candidates for hair transplantation due to extensive hair loss. We are

developing a regenerative medicine approach to hair restoration based on patient-derived induced

pluripotent stem cells (iPSC) transplanted in a biodegradable scaffold.

Methods/Technique

:

To generate de novo hair follicles, patient-derived cells were first isolated and reprogrammed to create

induced pluripotent stem cells (iPSC). iPSC were then differentiated into dermal papilla (iPSC-DP) and

epithelial stem cells (iPSC-EpSC), combined, and cultured in 3D to form hair follicle organoids. The cells

were characterized using flow cytometry, RNA sequencing, and immunocytochemistry; the iPSC-DP and

iPSC-EpSC were further compared to native cells isolated from hair follicle transplantation procedures.

The organoids were loaded into degradable scaffolds for ease of transplantation and directed cell

growth. The cell-loaded scaffolds were then transplanted into the backs of nude mice and observed for

60 days for de novo hair follicle generation. As controls, and to study the contribution of each of the cell

types on folliculogenesis, iPSC-DP were combined with mouse keratocinocytes (mKC) and iPSC-EpSC were

combined with mouse dermal cells (mDC) As scaffold controls, each of the cell combinations was also

injected into the dermis of nude mice via “patch assay.” Emerging hair shafts for all cell combinations,

with and without scaffolds, were visualized; hair follicles were excised and analyzed via

immunohistochemistry

Results/Complications

:

In vitro, the 3D co-culture of iPSC-DP and iPSC-EpSC resulted in the expression of native human hair

follicle biomarkers, as analyzed by flow cytometry, RNA sequencing, and immunocytochemistry. We

observed spontaneous formation of organoids resembling hair follicles upon co-culture of iPSC-DP and

iPSC-EpSC, with a clear separation of DP and EpSC in the developing hair follicle. In vivo, transplantation
of scaffolds containing iPSC-DPs and iPSC-EpSC in combination with mKC and mDC into nude mice

resulted in de novo hair follicle generation with multiple hair shafts. Analyses of the hair follicles

documented expected stereotypic positions of DP cells occupied by human iPSC-DP within newly

generated hair follicles.

Conclusion

:

We have demonstrated de novo generation of hair follicles by co-culturing patient-derived and

differentiated cells within a biodegradable scaffold. This technology will provide an unlimited source of

patient-specific hair follicles to address a range of hair loss disorders.