Moisturizing products are the most used skin care products in life, which shows the importance of moisturizing to skin health. However, there are still many misunderstandings about the application of moisturizing products in daily life.
Experts from the Dermatologist Branch of the Chinese Medical Doctor Association wrote the "Skin Care Product Dermatology Application Guide", specifically mentioning the application of moisturizing skin care products, the following is interpreted in more popular language, let's follow the experts to explore the mystery of skin moisturizing and take good care of the skin!
Interpretation 1: How does the skin moisturize?
The skin is made up of the epidermis, dermis, and subcutaneous tissue from the outside to the inside. The outer layer of the epidermis is called the stratum corneum, and in the past, it was thought that the cells of the stratum corneum were senescence and death, and the cells that gradually fell off had little value. However, it was later discovered that the stratum corneum is very important to the skin and is the front line of defense for human beings, and scientists figuratively call it a "brick wall structure".
Dead lifeless keratinocytes are hard "bricks", and the "mortar" filled between the bricks is composed of lipids such as ceramides, fatty acids, and cholesterol. Like the Great Wall, they play a very important protective role on human skin, called "skin barrier", which has the effect of locking skin moisture and resisting the invasion of various skin surface bacteria into the human body. Destruction of the skin barrier can lead to skin sensitivity at best, and skin diseases of varying degrees at worst.
Although the epidermis is an important structure for skin moisturizing, the real water storage is the dermis, 75% of the water in the skin is stored in the dermal matrix, which combines a large amount of water with amino glycans and protein complexes. For example, the spatial spiral column configuration in the hyaluronic acid molecule in the dermis can form hydrogen bonds with water, which can be combined with water 1000 times its own weight.
The collagen hydrolysate polypeptide chain contains hydrophilic groups such as amino groups, carboxyl groups and hydroxyl groups, which also have good moisturizing properties for the skin. Such biological macromolecules combine free water in a three-dimensional network structure formed by themselves, so that free water becomes bound water and is not easy to evaporate and lose. In addition, our small sweat glands absorb water-soluble substances, and the secreted sweat participates as an aqueous phase to form a sebum membrane. The sweat secreted by the small sweat glands plays an important role in moisturizing the skin and preventing dryness.
In short, through the blocking effect of the above stratum corneum barrier, dermal hyaluronic acid and other storage, binding water, etc., maintain the dynamic balance of skin moisture. This balance can be disrupted by various internal and external factors, and the balance will be lost.