Stem Cells for Hair Growth

Stem Cells are at the core of all dynamic events that includes a new burst of activity and further morphogenic remodeling as the follicle grows again at the start of a new anagen phase.

What is a Stem Cell? The term stem cell is given to a cell which has the ability to self renew (make copies of itself) as well as differentiate (develop into more specialized cells). This means that stem cells have the ability to become the cells they need to be in order to aid in the bodies regenerative processes like becoming cardiovascular cells,tissue cells,and even the cells in the hair follicle which grow hair. Infact, hair follicles are one of the best model systems for studying adult stem cells because hair follicles are accessible,well defined in terms of their developmental biology,and their stem cell populations are located in discrete components or niches.

Hair follicles are made up of many different components,but there are 4 that play a pivotal role in the growth of new hair:

Papilla-made up of stem cells,connective tissue,& blood vessels that aid in creating new hair as well as nourishing growing hair. It exists at the very base of a hair follicle.

Germinal Matrix-also referred to as the “matrix” is where cells produce new hairs as hairs die and fall out. It is also located in the lower region of the hair follicle.

Bulb-is a bulb-shaped, rounded structure at the bottom part of the hair follicle ”stocking” that surrounds the papilla and the germinal matrix and is fed by blood vessels. This is the living part of the hair. The bulb holds several types of stem cells that divide every 23 to 72 hours,faster than any other cells in the body. The bulb also contains hormones that affect hair growth & structure.

Bulge-the bulge area is located in the middle part of the hair follicle. It contains stem cells that divide and regenerate new hair follicles.

The cycle of a hair follicle. The hair follicle is a complex system made up almost entirely of stem cells. It is because of the signaling and interactions between these various stem cells that begins the process of creating new hair. In order to produce new hairs,existing follicles undergo cycles of growth (anagen) lasting 2-6 years in normal scalp hair follicles, regression (catagen) lasting 2-3 weeks, and rest (telogen) lasting roughly 3 months. During each anagen phase, follicles produce an entire hair shaft from tip to root; during catagen and telogen, follicles reset and prepare their stem cells so they can receive the signal to start the next growth phase and make the new hair shaft again.

Alopecia (hair loss) is caused by a variety of factors including genetic factors,medical conditions, hormonal disorders,auto- immune disorders, nutritional  disorders, environmental factors, psychological factors,and ageing. These damaging factors affect the hair cycle and decrease stem cell activity and the capability of the hair follicle to regenerate. Alopecia involves changes in 2 types of hair stem cells,both human hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs). These cells ensure conditions for proper hair regeneration.

We know that stem cells can be used to regenerate hair in several therapeutic strategies: reversing the pathological mechanisms which contribute to hair loss and regeneration of complete hair follicles from their parts.

Adipose(fat)- derived stem cells contain stromal vascular cells,mesenchymal cells,progenitor cells, and a variety of growth factors that can be harvested from fat cells. Because hair follicles are dependent on these molecular factors for normal cycling and morphology, utilizing adipose-derived stem cells for the treatment of hair loss is one of the latest and most fascinating breakthroughs now available in the field of aesthetic medicine.