Cloning means the reproduction of the genetically same living beans. In the cloning of “Dolly” the sheep that is known as the first clone being, one of the normal sheep body cells has been taken and the genetical material in its nucleus has been transplanted in a sheep ovule of which genetic material has previously been extracted. In this ovule that was fertilized with chemical/electrical stimulations, zygote generation has been initiated. When the cloned embryo has reached a certain size with cellular division, it was transferred to the sheep womb, and its growth and development were ensured.
What is tried to be accomplished with genetic engineering, apart from cloning, is to find and determine the gene that causes hair losses or another disease, and then to fix the disorder in this gene and put it back into the cell nucleus again after replicating it.
In a study conducted in the USA, it has been proven that when dermal papilla cells located in the lower part of human hair follicles are taken from one person and injected to another, they might allow for the generation of new hair cells. Even though this process is not a real cloning, it was shown that when dermal papilla cells are produced in petri dishes in a testing laboratory and injected to another person, they can initiate the generation of terminal hair bulbs. This hair induction model is the one that are currently the most focused on and may open new horizons for us. One of the important points in this study is that even though the dermal papilla cells were taken from a male, they were given to a female and the generation of hair bulbs took place in a female. In other words, despite the fact that there was a cell transfer between two different individuals, there has not been a phenomenon like tissue rejection. This, in a way, shows that hair bulb dermal papilla cells have a structure that is exempted from immunity just like cartilage tissue in our body. The transfer between individuals opens new horizons for us as a life-saving procedure in rare cases where a total hair loss is in question.
Previously, it was shown that new hair follicle could be generated in the mature skin with the mesenchymal papilla cells harvested from hair follicles in rats. In these experiments conducted on rodents, the dermal papilla cells that were cultured in the lab could come together both in the test environments and after being injected under the skin, and initiate the new hair bulb generation and grow new hair from the scalp.
It is unfortunately an unseen phenomenon that human hair cells come together and combine to constitute the nucleus that will generate a new hair. Dermal papilla cells that are injected under the human skin and that provides hair generation scatter and disappear without being able to create a structure that will generate the new hair.
It is important that human dermal papilla cells are in the fibroblast structure because, as is known, the fibroblast cells are the cells that are cultured most easily. In other words, the individual may have the stem cell culture that can create many hair bulbs from one single hair follicle in their own body. With this infinite cell culture implantation, the patient will be able to get rid of the alopecia problem. However, the important point here is that the hair follicle cells cultured in laboratory may change after being cultured and transform into different sorts of cells and connection tissue cells with different roles. For this reason, the hair follicle cells are considered as remedial cells that play important role in curing skin injuries or healing wounds in traumas. This case, of course, leads to this question without an answer: When dermal follicle cells are injected under the skin in the test conducted on humans, will they really create a nucleus that generates hair bulb or will they turn into cells that have different functions in different species?
There are 2 main hypotheses taken into consideration during hair cloning:
1)Hair follicle derma cells come together after the injection under the skin, change into new hair bulb cells and initiate a hair generation from scratch.
2)By stimulating existing thinned dermal hair follicles, it allows them to grow, develop and produce terminal hair that is stronger and thicker than the thinned hair called fuzz. However, there has not been a positive result from this kind of experimental studies yet.
Trying to reproduce dermal cells in culture environment means that they are taken from the environment where they communicate with 3 dimensional and different sorts of cells that they got used to and carried to a 2 dimensional environment, and that the intercellular communication changes dimension. In humans, maybe, this is why the cells do not come together after being injected and fade away by falling apart. In order to prevent this, the core cells that will create hair bulbs have been growth in hanging drop cultures and cultured as 3 dimensional dermal corpuscles.
Positive results are reported from these studies. It has been reported that the cells preserved the communication between them without disturbing their structure and genetic features and that they generated the new hair follicle by initiating the steps that would be the beginning of the new papilla generation. In other words, it is safe to say that human hair follicles have been cloned and hair generation have been successfully ensured. However, unfortunately, the generated hair are pretty small and in different directions; on the other hand, it is unknown for how long they can remain as hair follicles without changing and shedding, and whether they enter a normal hair life cycle or not.
There is still a long way to go
There is still a group of problems in front of us in terms of hair cloning. Firstly, the selection of the most suitable harvest cells: In addition to the difficulty of harvesting dermal papilla cells, their potential of generating good quality hair has probably been determined low. The second matter is the difficulties that will be experienced in the in-vitro production of selected cellular components. Another problem is the need for a cellular matrix structure that will keep cells together and in a good array in their development stage. The last is to be able to inject this generated cell culture to the receiver and finally to make quality hairs grow from the scalp. On the contrary to the hair transplantations performed today that we achieve almost perfect results, the growth of hair in the direction of natural hair growth, which is desired, cannot be guaranteed with the injected cell culture. It is also not guaranteed that the hairs grow with desired touch, color and thickness. In other words, after traditional hair transplants, we are not sure that the hair bulbs that would possibly grow in the adequate thickness and length when we apply such an injection even for hair densification. Another subject that remains unknown is whether the hair that grow by cell culture injection can grow for a second time after shedding within a normal life cycle. Normally, hairs have a lifetime of 2-6 years. After our hair sheds, the hair bulbs start to produce hair following a resting and break period of 3 months, and this cycle continues for our lifetime. In other words, we do not yet know whether these hairs have a normal life cycle.
On the top of the most important technical problems, it has been observed that the dermal stem cells in the cell culture have transformed in time during the development stage not into hair cell but normal fibroblast. It seems to be the most significant problem to ensure the development and change of all cultured cells for generating hairs by preparing a suitable media culture environment.
Even though it seems to be a remote possibility, it should not be ignored that there is a possibility that these cells stimulating the hair growth may lead to tumorigenesis or malignant tumors.
Even after overcoming all these difficulties and problems, receiving the approval of the FDA (American Food and Drug Administration) and routinizing this procedure would depend on safety and effectiveness researches that would last years, three phase clinical tests and controlled experiments. Hair cloning seems to be a model that is still in the preparation phase and that is away from perfection despite recent successful results. It seems that we still have a long time for abandoning the hair transplantation and fixing the baldness with hair clones.