Maintaining healthy hair is deeply rooted in understanding and taking care of hair structure. Taking care of damaged hair is an essential aspect of hair care and brands need to accurately measure the efficacy of their formulas with techniques like DVS (dynamic vapor sorption) This technique measures the capacity of hair in absorbing external humidity and is key to determine hair damage, as the more damaged is the hair, the more humidity it absorbs. Here, we discuss the crucial connection between hair structure, hydration, and methods to measure enhance hair humidity .
First, we’ll outline the key characteristics of a strand of hair. Hair is a structure composed of obliquely arranged flexible cylindrical filaments. These filaments consist mainly of proteins, water, lipids, and pigments, but 80% of human hair is formed by keratin, a water-insoluble fibrous protein that is mostly found in hair, skin, and nails, as found by Robles Velasco, M.V. et al, 2009.
Hair structure is mainly built around two parts; the hair follicle is the internal part and the shaft is the external, visible part. Each of these parts is also split into several other divisions.
In order to improve hair health, there are three physical properties that can be treated:
- Elasticity: the capacity of hair to go back to its normal shape after being stretched or deformed. This property mainly depends on the state of the hair cuticle and its cell adhesion. Water improves hair elasticity, as it reacts with keratin.
- Tensile strength: this allows hair to stretch and resist some weight without breaking. Hair strength depends primarily on the number of bonds within hair structure and especially on disulfide bridges.
- Permeability: the hair’s capacity to absorb external agents or, instead, acting as a barrier against their entry. This mainly depends on the state of the hair cuticle.
A treatment with active ingredients that go to the root of the problem will be able to act upon these properties and hair structure and composition. To improve hair health through hydration, permeability plays a primary role and should not be underestimated.
The key role of DVS and permeability in measuring hair damage
Hydration is an essential process for the human body, as water has a great influence on maintaining health. However, the process of hydration works differently on the diverse tissues and proteins that form the human body.
A study by C. Barba et al. found that there are significant differences between the best route to hydrate skin and the best options to hydrate hair. Intercellular lipids, they proved, played a bigger role in skin hydration than they did in hair hydration. In conclusion, different routes must be followed in order to hydrate these two different structures.
In hair, it’s permeability in particular that greatly influences the hair’s capacity to retain or absorb water, and thus becomes relevant for any hydration treatment. But while water content in hair has been found to be essential for its health, it’s difficult to measure. In order to study the hydration level in a tissue, the DVS technique has been found to be extremely useful. DVS (dynamic vapor sorption) or isothermic balance permits an analysis of how a sample’s mass is affected by humidity changes. It also includes the study of phenomena such as absorption, adsorption, and desorption. The study of the adsorption and desorption of water by hair fibers provides information about the kinetics of water diffusion and the permeability of these fibers. It thus allows researchers to learn about how to best hydrate hair.
When looking at permeability, it’s hair cuticles that play the main role. Through cuticles, hair can naturally absorb water directly and from the atmosphere. From here, it can reach up to an extra 40% of its weight. However, hair cuticles can be altered through different processes, such as those used for hair dye or highlights. This endangers hair health and thus must be treated to avoid dry, unhealthy hair.
Keratrix, the natural active ingredient to treat damaged hair
Keratrix is a natural active ingredient that provides a profound and effective treatment for damaged hair by targeting properties including elasticity, strength, and permeability. Keratrix improves hair fiber integrity by treating damaged hair and focusing on healing it, and getting permeability values close to those of untreated, healthy hair.
In order to do so, Keratrix contains biofunctional peptides and amino acids from the carob tree, a southern Mediterranean species whose seeds contain great hydration powers. Furthermore, its sustained release system allows this active ingredient to remain on the hair fiber long enough for prolonged action and treatment. This is achieved through a controlled sequential release system developed by Provital named Matrix Plus, which attaches to the hair fiber and increases contact time.