| There are many limitations to cosmetic, medical and | | | | cell culture. The newly multiplied cells would then be |
| surgical treatment methods currently in use for hair | | | | re-implanted into the recipient area of the scalp so |
| loss. Newer treatment methods will eventually | | | | that new follicles are created. Because of the cell |
| emerge, which potentially have the ability to "cure" | | | | division that occurs while culturing, countless new cells |
| inherited patterned baldness permanently. These | | | | are created that when implanted, result in hundreds |
| methods encompass the concepts of Hair Follicle | | | | of NEW HAIR FOLLICLES. |
| Cloning and Gene Therapy. | | | | BACKGROUND |
| Hair follicles are miniature hair growing organs which | | | | The basis for Follicular Cell Implantation (FCI) began in |
| evolve through growth and rest cycles. In addition to | | | | the fundamental investigation of normal hair growth. |
| hairs being grown and then shed in these phases, the | | | | Hair growth results from a DYNAMIC INTERACTION |
| follicle itself disintegrates almost entirely by the end | | | | of epidermal and dermal components. This |
| of the regression phase, and an almost entirely new | | | | DERMAL-EPIDERMAL INTERACTION is what |
| follicle is created at the beginning of the next growth | | | | determines follicular development in the fetus, as well |
| phase. This presents a unique opportunity for applying | | | | as normal hair shaft production during anagen. |
| advanced molecular biological and medical techniques | | | | Colin Jahoda showed the validity of this interaction by |
| resulting in cloning and gene therapy. | | | | taking cells of the rat whisker dermal papilla, growing |
| Cell Biology and Genetics | | | | these cells in culture and implanting the cultured cells |
| Cells are the basic unit of all living organisms. The hair | | | | into incisional skin wounds of the rat. The implanted |
| follicle is a miniature organ in which there are several | | | | cells induced hair growth by interacting with native |
| different types of cells working together to grow a | | | | epithelial cells to re-create hair follicles and produce a |
| hair. Inside of every cell there is a NUCLEUS that | | | | hair shaft. This is similar to what happens during |
| contains CHROMOSOMES composed of DNA, the | | | | FETAL DEVELOPMENT of the hair follicle and the |
| genetic material of the cell. Genes are sections of | | | | normal ANAGEN PHASE of the growth cycle. Several |
| DNA that contain the code for particular types of | | | | investigators, including Jahoda, Cooley and Vogel, |
| proteins. Proteins, in turn, determine actual | | | | Unger, and the Aderans Research Institute have |
| characteristics such as hair color, eye color, baldness, | | | | replicated this work in humans. The problem is that |
| etc. | | | | nothing has appeared in the way of detailed studies |
| Each cell in a multi-cellular organism contains in its | | | | to describe the actual TECHNIQUES used in these |
| chromosomes a COMPLETE DNA BLUEPRINT of all of | | | | human studies. Because of the inherent commercial |
| the genes for the proteins for the entire organism. | | | | value of successful research, the importance of |
| Unlocking this DNA information in mature specialized | | | | protecting intellectual property has overshadowed |
| cells is an important aspect of some cloning | | | | the impetus to publish. |
| techniques. | | | | APPLICATIONS |
| Cell Replication | | | | Using TISSUE ENGINEERED cells to treat hair loss is |
| In a rapidly growing embryo, cells replicate by splitting | | | | conceptually quite simple, but many complexities and |
| in half and then growing to full size again. This | | | | challenges obscure this application. Research efforts |
| process is called cell MITOSIS. Each half of a cell that | | | | span over twenty years yet the results have been |
| splits contains a complete and exact set of the | | | | inconsistent at best. This points to various |
| organism's DNA. As the embryo grows into a more | | | | OBSTACLES that have yet to be overcome. A |
| fully functional organism, its cells begin to take on | | | | sampling of the major concerns are as follows: |
| more specialized characteristics and begin to divide | | | | (1) Autologous vs Allogenic Tissue: Must the tissue |
| less. As cells become more specialized, cell replication | | | | used be that from the individual who will undergo the |
| shifts to more specialized cells called STEM CELLS. As | | | | procedure or can tissue from another individual be |
| specialized cells wear out over time they must be | | | | used to create engineered follicles? Some portions of |
| replaced from this pool of stem cells, which can | | | | the hair follicle seem to be immunologically "privileged", |
| create many different types of specialized cells. | | | | but whether allogenic tissue will work is unknown at |
| CLONING | | | | this time. |
| The background of cellular biology as presented | | | | (2) Which follicular cells must be cultured and |
| above forms the scientific basis for cloning. Cloning is | | | | implanted? There is controversy regarding the type |
| defined as the creation of an EXACT GENETIC | | | | of cell to be cultured and implanted. Dermal cells, |
| REPLICA BY ASEXUAL MEANS. The use of fetal or | | | | epidermal cells, stem cells and germinal epithelial cells |
| embryonic tissue is an integral part of this technology. | | | | all may have the potential to form new hair follicles |
| Scientists CLONE a gene, a cell or an entire organism. | | | | when cultured, but there is no consensus on this in |
| Cloning as defined above must be distinguished from | | | | the research literature. |
| TISSUE ENGINEERING or CELL THERAPY. Tissue | | | | (3) The ability to maintain inductive potential is an |
| engineering involves culturing cells in vitro and | | | | important factor in implanting tissue engineered |
| re-implanting them. An example of such a tissue that | | | | follicles. After several passages in culture, papilla cells |
| could potentially be cultured and implanted is Hair | | | | lose their ability to induce hair growth when |
| Follicles. Tissues such as hair follicles are not referred | | | | re-implanted. This could potentially be a major |
| to as clones. | | | | obstacle for the development of a treatment for hair |
| In an imperfect world however, the following terms | | | | loss. |
| have become interchangeable: Hair Follicle Cloning, | | | | (4) The cosmetic characteristics of the resultant |
| Follicular Cell Implantation, Follicular Neo-genesis, | | | | cloned hair will be important. Color, orientation, curl |
| Follicular Regeneration and Hair Multiplication. According | | | | and caliber of the hair will have to be analyzed such |
| to scientific protocol however, the first term, cloning, | | | | that a "normal" looking result is achieved. |
| should be excluded from the list, as it is tissue | | | | (5) There are economic and regulatory hurdles that |
| engineering that forms the basis for the technique | | | | need to be overcome before FCI is considered a |
| described herein. | | | | treatment for hair loss. In the United States, the US |
| Why then, is research proceeding along these lines? | | | | Food and Drug Administration would likely regulate |
| What is the driving force and/or rationale for tissue | | | | implanted hair cells as "Biologic Therapy". This implies a |
| engineering or cloning? First, there is the promise of | | | | comprehensive regulatory framework and significant |
| UNLIMITED DONOR HAIR. There have been | | | | legal hurdles which could potentially impede or delay |
| countless times that a patient has been deemed not | | | | FCI as therapy for hair loss. |
| a suitable candidate for surgical hair restoration due | | | | (6) Finally, there is the question of safety. There |
| to the sparseness and quality of the donor hair. This | | | | must be an investigation into whether or not FCI |
| would never occur in light of unlimited donor. A | | | | could result in a tendency toward tumor formation. |
| second driving force would be the LACK OF A | | | | The question of the transmission of infectious |
| DONOR SCAR. This would please many patients and | | | | diseases, especially if allogenic tissue is utilized, will |
| physicians alike. The CREATION OF GREATER | | | | become of overriding importance in FCI therapy. |
| DENSITY and a more EASILY TOLERATED | | | | SUMMARY |
| PROCEDURE also make the concept of cloning | | | | FCI has the potential to overcome many of the |
| attractive to clinicians. | | | | limitations of current surgical hair restoration, |
| THE CONCEPT | | | | especially the finite supply of donor hair. The basic |
| Theoretically, the concept of tissue engineering would | | | | concept is sound, but reports in humans show |
| involve harvesting a small sample of hair follicles from | | | | inconsistencies and problems with reproducibility. The |
| the same donor region used in hair transplantation. | | | | prospect of an unlimited donor supply will continue to |
| The follicle inducing cells in the hair follicle would be | | | | influence tissue engineering based research to |
| isolated and subsequently caused to multiply using a | | | | overcome these obstacles. |