It has been previously shown that new hair follicles can be formed in adult skin with mesenchymal papilla cells obtained from hair follicles in rats. In these experiments in rodents, dermal papilla cells cultured, that is, reproduced in laboratories, could come together both in experimental environments and after being injected under the skin, and initiate the formation of new hair follicles in mice, that is, new hair could grow from the skin.
Unfortunately, it is a phenomenon that has not yet been seen in human cells that, after being injected into the skin, the cells clump together and form a core that will form a new hair by clustering. Unfortunately, dermal papilla cells injected into the human skin disperse and disappear before they can form a structure that will form new hair.
The most important problem in hair cloning is that the hair follicle cells produced in the laboratory, that is, cultured, can differentiate after their production and turn into different types of cells such as stem cells and connective tissue cells with different roles. Therefore, hair follicle cells are considered to be healing cells that play an additional role in wound healing in skin injury or trauma. This, of course, raises the following question: When dermal follicle cells are injected under the skin in experiments in humans, will they really form a core that will form hair follicles, or will they turn into different types of cells with different functions?
There are 2 main hypotheses discussed in hair cloning:
1) After the injection of hair follicle dermal cells into the skin, they come together and turn into new hair root cells and start a hair formation from nothing.
2) By stimulating the existing thinned dermal hair follicles, to enable them to grow, develop and produce stronger and thicker terminal hair than the so-called thinned quince hair. However , no positive results have been obtained from such experimental studies so far .
Trying to reproduce dermal cells in culture means taking them from the environment they are accustomed to in 3D and communicating with different types of cells, moving them to a 2D environment and changing the dimensions of intercellular communication. Maybe that’s why in humans, after being injected, the cells can’t come together and disperse and disappear. In order to prevent this, dermal papilla cells, that is, the core cells that will form hair follicles, were grown in hanging drop cultures and multiplied as 3D dermal globules.
Positive results have been reported from these studies, and it has been reported that the cells maintain the communication between them without disturbing their structure and genetic characteristics, and they form new hair follicles by initiating the cascade that will initiate the formation of new papillae. In other words, it can be said that human hair follicles have been cloned and hair formation has been achieved successfully. However, unfortunately, the hairs created are still very tiny, their directions are in different directions, it is unknown how long they can remain as hair follicles without changing and shedding, and whether they can enter the normal hair life cycle.