Scientists transplanted scalp cells from one person to another
and, for the first time ever, grew new hair on a human without
the use of drugs. The approach could someday enable just about
any head to sprout hair, researchers said.
The researchers, led by biologist Colin Jahoda at Durham University,
in Britain, took cells at the bottom of hair follicles from
Jahoda's own scalp and from a colleague's. These cells from
the so called dermal papilla were then transplanted into the
forearm of Jahoda's wife, Amanda Reynolds. Within five weeks,
the transplanted tissue - no bigger than the head of a pin -
made a total of five fully grown hairs in the Amanda's arm.
'It does show the potential of being able to induce new hair
follicles in human skin which I don't think has been done before.'
said Colin Jahoda. The transplanted tissue 'is telling the cells
of the recipient: You will make a new hair follicle,' Jahoda
said. The new hair was genetically male. It was longer, thicker
and darker than arm hair, but it combined some characteristics
of both donor and recipient.
Although the research was originally designed to test whether
the graft would be rejected by the genetically unrelated woman,
the researchers were pleased by the surprising results. 'You
can use a few cells to basically regenerate an entire organ.
To me, that's the mind-blowing part,' said Angela Christiano,
a Columbia University baldness researcher who did the genetic
analysis for the British experiment, reported in the journal
Nature. DNA samples taken from the newly sprouted hair contained
the Y male chromosome, proving that the new hair was from the
The new work suggests the possibility of a quick 'hair cloning'
procedure with the creation of new hair in just about anyone.
The cells could be removed from a person's own scalp or, if
that person cannot produce good quality cells, they could be
collected from someone else. They could then be multiplied through
laboratory cloning before being transplanted.
'Having the hair as an immunologically privileged organ would
be very, very important,' said Dr. Michael Bernstein, a hair transplant
surgeon who is medical director of the New Hair Institute in Los
Angeles. He said Jahoda's technique may give hope mainly to old
people who want new hair, patients with bad burns, or others who
for genetic reasons fail to make their own hair. He predicted
that bald men will be able to have their own hair cloned within
15 years or so.
The ability to induce new hair follicles by using dermal papilla
cells has been done previously in animal models. In fact we
have known about the ability to make new hair follicles using
cells derived from other hair follicles since the late 1960s.
However, this is the first time that the technique has been
successfully used in humans.
Even more interesting from the scientific point of view is
that the hair follicles were made in a woman using cells derived
from a man. Normally the foreign cells would be rejected by
the recipient. But the scientists suspect the cells taken from
the base of follicle may have some type of immune privilege
which allows them to mix with foreign cells. So instead of being
rejected by the woman's immune system, the male cells interacted
with her cells to create new follicles.
It is not yet clear whether such newly grown hair will last,
pop up at the correct angle or satisfy other requirements for
a cosmetically acceptable treatment. The microsurgery used in
the experiment is complex, time consuming, and expensive right
now. However, it could potentially be developed into a relatively
simple procedure. The greatest problem facing developers will
be to work out how to get the new hairs to all grow at an appropriate
angle to line up with the natural hair follicles on our scalps.
To do this will require that we understand much more about the
gene expression involved in the induction of new hair follicles
and what genes tell the hair to grow in a certain direction.
There is also the possibility that injecting cells that can
induce new hair follicles might also induce tumor development
and skin cancer in a few people. Such concerns will have to be
addressed before the treatment method becomes available to the