Scientists from Durham University in the UK have shown for the first time that a lab technique, called a three-dimensional cell culture, can produce spherical structures that are similar to naturally occurring structures in hair follicle formation (called dermal papilla or DP). This breakthrough study by Claire Higgins and Colin Jahoda, published in the June 2010 issue of the journal Experimental Dermatology, ((Higgins C, Jahoda C, et al. Modelling the hair follicle dermal papilla using spheroid cell cultures. Experimental Dermatology 2010; 19: 546–548.)) has the potential to unlock the ability of researchers to develop functional DP cells which can be used in hair restoration techniques such as hair cloning or hair multiplication.
Background
Hair cloning techniques have been theorized for decades. The basic idea is:
- a physician takes a sample of skin cells from a patient
- dermal papilla cells are extracted
- the DP cells are cloned (multiplied) in a laboratory culture (i.e., a petri dish)
- the cell formation is then injected back into the patient’s balding scalp where it produces permanent hair that continues to grow
The first three steps are a piece of cake. But that is when the strategy breaks down. When DP cells are grown in a petri dish they exhibit some of the qualities of DP cells in the human body but not all, so injecting this aggregate into the skin fails to lead to hair follicle growth. Something was missing.
In 1991, Wobus, et al published a study in the journal Differentiation ((Wobus AM, Wallukat G, Hescheler J. Differentiation 1991: 48: 173–182.)) that described a new technique for researching cells that in nature exist as clumps or masses of cells. The idea was to suspend a group of cells under a flat surface so that gravity would pull the cells into a droplet. This “hanging drop” method yielded a three-dimensional culture that enabled the study of embryonic stem cells as well as the proteins they produce that allow for intercellular communication.
Having hit the wall with two-dimensional DP cultures, Higgins and Jahoda set out to try Wobus’ concept of using 3-D cultures to study DP cells.
The Study
Higgins and Jahoda harvested eight cell strains of human DP cells taken from scalp hair follicles. These eight strains were cultured in either 35-mm dishes or hanging drop cultures consisting of 3,000 cells each. The cultures were maintained between 30 and 72 hours, then collected and analyzed using immunofluorescence or transcriptional techniques.
Results
The DP cells grown in hanging drop, 3-D cultures exhibited behavior significantly akin to DP in human hair follicles. The 2-D cultures grown in the 35-mm dishes did not.
Conclusion
Without the ability to form functional dermal papilla aggregations, hair cloning was essentially at a dead end. In the 3-D configuration, the aggregated cells were able to communicate with one another and to continue to differentiate as hair follicles. By using Wobus’ 3-D hanging drop technique, Higgins and Jahoda may have unlocked the secret to forming these powerful, but elusive, structures that are critical to the hair growth cycle.
Following this study, more research needs to be performed to induce the spherical cells to initiate the growth of new hair follicles and to develop ways to ensure that the induced hair follicles are immune from the factors that cause genetic hair loss. Should those two riddles be solved, hair loss will have been effectively cured.
Posted by Robert M. Bernstein M.D. 
