Hair follicles: unique depots and effective conductors of bioactive substances

In terms of the effectiveness of cosmetics, experts are divided into two camps: some are convinced that cosmetics work at the level of the stratum corneum, others believe that active cosmetic ingredients are able to penetrate into deeper layers of the skin. In order to find the truth between these two opinions, scientists are experimenting a lot with methods of delivering bioactive components with large molecules into the skin. Daniil Kashik – cosmetologist, head of the G&P Group training center, coach of Ukrainian Aestetics.

Features of the structure of the hair follicles, applicable for the delivery of substances

Studying the possibilities of delivering large molecules of bioactive substances to the deep layers of the skin has been going on for a very long time, both cosmetologists and pharmacists are engaged in this. In one of the studies on the possibilities of hair follicles, scientists found that if active substances are administered not between the follicles, as was customary, but directly through the epithelium of the hair follicle, then the substances are absorbed better and faster.

Juvilis specialists were able to  to determine the absorption parameters that would be optimal for the injected substance, if carried out into the skin through the hair follicles. In addition, it was found that immune and stem cells are concentrated in the region of the hair follicles, which makes it possible to stimulate cell proliferation when using the transfollicular route of delivering substances to the skin.

Scientists have found that hair follicles can serve not only as effective conductors, but also as reliable storages of bioactive ingredients. The Spanish company Juvilis was the first to use follicles as a depot for active particles in its own developed Fillertrans

technology.

Juvilis specialists have developed a technique for using filler active ingredients in transfollicular delivery. The essence of the technique is that with the daily introduction of filler substances into the hair follicle, a reservoir is formed there that stores ions and partially dissolved particles of the filler substance. From this reservoir, the active ingredients are gradually absorbed into the dermis, creating a prolonged therapeutic effect.

It has already been proven that the use of hair follicles as a reservoir for bioactive filler particles in no way interferes with the natural excretory functions of the follicle. After one injection of the filler substance, the follicles are able to store it for about 10 days, while they remain in the stratum corneum for no longer than 24 hours.

How particles in hair follicles are activated and what can be achieved

It should be noted that in the hair follicles the derivatives of the – active particles that are formed during its degradation. Each of the fillers presented on the aesthetic market today has its own degradation pathways and its own active particles, for example:

• Hydroxyapatite (Hap) – breaks down into calcium ions and improves skin microrelief;
• Tricalciumphosphate (TcP) – breaks down into phosphate ions and improves skin elasticity;
• Poly-L-Lacticacid (PLLA) – breaks down into lactic acid and promotes cell renewal.

Juvilis experts conducted a study involving six volunteers who were applied to the skin of the hands of two different formulations – one of them contained tricalcium phosphate, and the other hyaluronic acid. The aim of the study was to confirm the fact that the substance can be absorbed through the hair follicle and create a depot of active particles there. The results were monitored by confocal microscopy.

Three days after the application of the filler compositions, measurements were taken and images were recorded using a microscope, where the presence of dissolved particles of the filler substance in the papillary dermis was clearly monitored. No such particles were found in the placebo area.

This study confirms the importance of the hair follicle epithelium for the success of cosmetic procedures.

There are quite a few companies on the cosmetology market that use transfollicular delivery of bioactive substances in their methods, but the Spanish company Juvilis, represented on our market by LLC "Ukrainian Aesthetics", is the first and only one to date to use it in filler substances in their products.