Introduction
Hyaluronic acid is one of the essential cosmetic elements and can exist in various forms. Even though it is added to skincare products, it naturally exists in the human body. Hyaluronic acid is not an acid in its ordinary sense despite its name. It does not have dissolving or exfoliating properties, such as glycolic acid. Hyaluronic acid is sugar, but if the molecular weight of table sugar is about 340 daltons (Da), then hyaluronic acid is from 600 thousand to several million Da. Due to their structure and considerable molecular weight, their molecules can hold much water many times greater than their own. In the human body, hyaluronic acid performs the crucial function of retaining moisture in the tissues and acts as a lubricant for the joints.
Hydrolyzed Hyaluronic acid
It differs from ordinary hyaluronic acid in the size of the molecule. Moreover, this acid can penetrate the skin without injections since hydrolyzed acid molecules can fill the intercellular space (West et al., 2021);. It is obtained by splitting into ordinary acid molecules by hydrolysis. Small nanoparticles of hydrolyzed hyaluronic acid penetrate the deep layers of the epidermis, filling the skin with moisture, improving its appearance and complexion. This acid has the main property – to retain moisture in the deep layers of the skin. One acid molecule contains 200 – 500 units of water and maintains skin elasticity (West et al., 2021). Since low molecular weight acid can penetrate deep layers without injections, it can be used independently at home. Its use helps to reduce wrinkles and deeply moisturize the skin, thicken the upper layers of the epidermis, reduce skin dehydration, and tighten the matrix (Juncan et al., 2021).
Sodium hyaluronate
Sodium hyaluronate is a salt of hyaluronic acid, isolated in the laboratory through hydrolysis, detachment from the molecule of ineffective components (Chiu et al., 2018). Thus, a substance with a much smaller molecular volume is formed. The result is a low molecular weight substance, which can penetrate the deepest layers of the epidermis due to its small size. Sodium hyaluronate has a broader range of functions than hyaluronic molecules. In addition to all of the above, the substance can stimulate the production of hyaluronic acid itself, collagen, and elastin, which keep the skin young and fight age-related changes. In cosmetics, it is used as a very active moisturizer – it retains water very well and penetrates the skin – very effective moisturizing is obtained. It is not considered a toxic ingredient but may irritate sensitive individuals.
3D-hyaluronic acid
Among modern forms of hyaluronic acid, 3D-hyaluronic acid occupies a special place. This is an innovative active complex that contains hyaluronic acid molecules of different sizes (molecular weight), which provides a prolonged three-dimensional effect on all levels of the skin at the same time. High molecular weight acid intensively moisturizes the stratum corneum, prevents moisture loss from the dermis, has a healing and antioxidant effect (Zhang et al., 2018). Molecules of medium size penetrate the epidermis, intensively moisturize, smooth the skin, help reduce the severity of wrinkles. Low molecular weight acid penetrates the dermis, strengthens the cellular matrix, stimulates the synthesis of its hyaluronic acid, collagen, and elastin, and is a conductor for other assets.
Areas of use
Even though hyaluronic acid is a component of the body, the skin needs cosmetics to maintain elasticity. Cosmetic products based on hyaluronic acid are moisturizing and anti-aging agents. However, it should be mentioned that products containing hyaluronic acid make up about 5% (Juncan et al., 2021). At the same time, approximately 94-95% are cosmetics and care products based on sodium hyaluronate (Juncan et al., 2021). At the same time, although 3d hyaluronic acid has become more actively used in cosmetic procedures, the percentage of its use is small and amounts to about 1-2% (Zhang et al., 2018). Hyaluronic acid products also contain plant extracts that have additional effects such as antioxidant, anti-inflammatory, conditioning, whitening, or photoprotective properties of the skin.
Conclusion
In modern cosmetology, considerable attention is paid to developing and using products based on hyaluronic acid. The effectiveness of hyaluronic acid depends on the molecular weight. Thus, the skin receives various effects, including moisturizing, regeneration, or rejuvenation. Hydrolyzed hyaluronic acid penetrates the skin without injection due to the size of the molecules and moisturizes the skin. Sodium hyaluronate is even smaller and therefore penetrates the deeper layers of the skin, stimulating collagen production. 3D hyaluronic acid works as a complex containing molecules of different sizes. This type of hyaluronic acid affects different dermis levels, including moisturizing, preventing moisture loss, and reducing wrinkles. Some products based on hyaluronic acid can be used at home, while others are introduced into the body through cosmetic injections.
Reference list
Chiu, Y. H., Chen, M. C., & Wan, S. W. (2018). Sodium hyaluronate/chitosan composite microneedles as a single-dose intradermal immunization system. Biomacromolecules, 19(6), 2278-2285.
Gupta, R. C., Lall, R., Srivastava, A., & Sinha, A. (2019). Hyaluronic acid: molecular mechanisms and therapeutic trajectory. Frontiers in veterinary science, 6, 192.
Juncan, A. M., Moisă, D. G., Santini, A., Morgovan, C., Rus, L. L., Vonica-Țincu, A. L., & Loghin, F. (2021). Advantages of hyaluronic acid and its combination with other bioactive ingredients in cosmeceuticals. Molecules, 26(15), pp. 1-43.
West, B. J., Alabi, I., & Deng, S. (2021). A Face Serum Containing Bakuchiol, Palmitoyl Tripeptide-38, Hydrolyzed Hyaluronic Acid and a Polyherbal and Vitamin Blend Improves Skin Quality in Human Volunteers and Protects Skin Structure In vitro. Prepints, 21(3), pp. 19-23.
Zhang, X. O., Lv, Y., Mao, H., Fan, X. Y., Huang, S. L., & Guo, X. P. (2018). Hyaluronic acid scaffolds: application research and product prospects. Chinese Journal of Tissue Engineering Research, 22(2), pp. 294.