Bernstein Medical - Center for Hair Restoration - Dermal Sheath

Dermal Sheath

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Q: Considering cell cultivation is made possible how could their injection create a normal formation of hair on the scalp and can they induce hair growth also in scarred areas where previously hair stopped growing?

A: That is the question. It is not known if these induced follicles will resemble normal hairs, and be cosmetically acceptable on their own, or if they will grow unruly and must be used as a filler behind more aesthetically pleasing transplanted hair.

Hair growth is an interaction between the dermal components (fibroblasts in the dermal sheath and dermal papillae) and the epidermal structures.

It is possible that the injected dermal fibroblasts will interact with resident epithelial cells to produce a properly oriented hair. A tunnel of epithelial cells can also be created to facilitate this process and some researchers are using cultures of both dermal and epithelial cells.

As you suggest, part of the challenge is not just to multiply the hair but to find a way for the hair to grow in its proper orientation. With scar tissue, the task will obviously be much more difficult.

Another issue is that the induced follicles are just that, they are single hair follicles rather than complete follicular units. Because of this they wouldn’t have the cosmetic elegance of one’s own natural hair, unlike that which is possible in follicular unit hair transplantation.

That said, much work still needs to be done and it is not clear at this time what might be the solution.

Read more on the Hair Cloning page on the Bernstein Medical – Center for Hair Restoration website.

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Q: I was reading the hair cloning area on your site and came across this passage:

“Donor cells can be transferred from one person to another without being rejected. Since repeat hair implantations did not provoke the typical rejection responses, even though the donor was of the opposite sex and had a significantly different genetic profile, this indicates that the dermal sheath cells have a special immune status and that the lower hair follicle is one of the body’s ‘immune privileged’ sites.”

Does this mean that I could get a hair transplant from someone else’s head of hair one day? Any type of hair?

A: Yes, in theory we will be able to use someone else’s donor tissue to clone hair – but the technology to actually do this is still years away.

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Q: When a donor strip is taken out during a hair transplant and separated under the microscope, you can read on the internet that there is a wastage of grafts (about 15%), because of those unseen telogen hairs. What do you think about that and how does it affect the hair restoration? — T.B. Baldwin, New York

A: The Telogen phase of the hair cycle is about 3 months long and about 12% of follicles are in this phase at any one time. It is speculated that the follicles may be empty for perhaps 1/2 that time (this number may vary significantly between people). Therefore, approximately 6% of the hair follicles may be in telogen at any one time.

On average about 15% of the follicular units are 1-hair units (but this also may very greatly between patients). If 6% of all follicles are “empty” telogen follicles, then there should be .15 x .06 = .009 or about 1% of the patient’s 1-hair follicular units in the empty telogen phase that can’t be identified and will be missed on dissection.

The 1% isn’t very large. However, also consider that the remaining 5% of the empty follicles are associated with larger follicular units (i.e. those with 2-4 hairs). If these follicular unit grafts are closely trimmed, as is the practice with very dense packing, a much more significant number of follicles are at risk of being lost. With chubby follicular unit grafts (i.e., where the microscopic dissection leaves a protective sheath of tissue around the follicles) the risk should be closer to the 1%.

The lesson for hair transplantation is that over-trimming of grafts, for the sake of very dense packing, may waste telogen hairs as well as place the grafts at an unnecessary risk of mechanical trauma, drying and warming.

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