Detailed information about bioengineering the hair follicles

Approaches

Bioengineering

When tissues, cells and molecules of any biological organism are manipulated using principles of engineering and natural sciences, it is called bioengineering. Bioengineering involves understanding the way of functioning of biological organisms and applying engineering technologies to develop new devices, like diagnostic or therapeutic instrumentation.

Bioengineering the hair follicles

Hair does play a critical role in the psychological health of a person as it is related to one’s own perception about how one looks. For both men and women, looking good is extremely important so far as self-confidence is concerned.

So when hair starts falling rather rapidly, the affected individual invariably looks for help. He/she tends to look for and try out whatever he/she can to arrest the hair loss such as taking regular medicinal treatments, trying out alternative systems of medicine, or even opting for hair weaving and wigs.

But the ultimate therapy, of course, would be to restore or regenerate new, healthy, cycling hair follicles.

Hair follicles are small but powerful hair growing factories. But the production is not continuous, it goes through a cycle comprising stages of rapid growth, and intermittent regression period, and finally shedding of old hair in a resting phase before resuming a new growing phase. This entire process is termed the follicle growth cycle.

To maintain and control this cycle in the right way, it is required that the principal cell types in the follicle retain powerful interactive signaling properties.

There has been a major breakthrough by scientists where they have isolated dermal cells from the base of hair follicles and shown that small collections of these cells can induce new hair follicles when combined with the epidermis.

Thus to bioengineer the hair follicle, dermal elements from dissociated follicles, with or without competent cells from the follicle or other epithelial sources, are the starting block. The number of dissociated cells would be expanded in culture and then dermal cells alone, or in combination with competent epithelial cells, re-introduced to the bald scalp. These cells would then induce new hair follicles to grow.

Approaches and possibilities to bioengineer the hair follicle

In order to avoid immune rejection of the donor cells, bioengineering approaches to treating alopecia by manipulating hair follicles autologous tissue (that means tissue taken from the same person to which the tissue cells are going to be implanted) are likely to be used.

However, the hair follicle is an immune-privileged site that does not express MHC (major histocompatibility complex), class I antigens. In principle, this property means it can be used to develop heterologous (that means taking tissue from one person and implanting cells from it into a different person) hair follicle tissue for tissue transplantation. This approach has already been used successfully in one experiment. As these tissues have already been transplanted from one individual to another successfully, this possibility sure is worth taking a shot at. Nevertheless, the safety testing and regulatory hurdles for this type of approach would require enormous financial resources. For now, this kind of approach is beyond the financial means of most companies to develop into a clinical treatment.

One more approach can be to develop hair follicles as mini organs in vitro, and then implant these new follicles into bald portions. But this would require a much more complex cell culture system involving three-dimensional matrices, perhaps embedded with appropriate growth factors, to allow both dermal and epidermal cells to differentiate towards a normal hair follicle.

Yet another approach can be to use biocompatible materials. This way hair follicle cells can be genetically manipulated ex vivo. This would result in easier surgical placement of the new hair follicle in the proper orientation.

These approaches are being considered by several companies that are trying to bioengineer hair follicles. Which approach will be successful is not clear yet. However, the research in the next few years should indicate a clear winner.