What does “barrier repair” repair? How to match different skin types?

Barrier repair is often mentioned, and even many fat friends will ask questions such as “I feel like I have a barrier.” In order to avoid any skin problems falling into the misunderstanding of “barrier repair”, and in order to prevent real skin damage. Fat friends who have problems can better understand their skin so as to better match products. This time I will systematically explain what is repaired by “barrier repair”? How to fix it?

Before we understand how to repair barriers, we must first know what exactly is a barrier?

1. Understand the “skin barrier”

Skin barriers include physical barriers, pigment barriers, nerve barriers, and immune barriers. What we usually call “barrier repair” generally refers to the “physical barrier”, which is what we know as the “stratum corneum”.

The physical barrier is a unique brick wall structure. To build a wall, you need bricks + cement; if there are only bricks, they will fall down when pushed; if there are only cement, you cannot build a wall at all, so a healthy skin A barrier requires enough bricks and cement to be constructed.

Bricks refer to the keratin cells in the stratum corneum, and one keratin cell is equal to a brick; keratin cells are inanimate dead cells, and they constitute the bricks in the brick wall structure. The “bricks” piled up layer by layer, combined with the “cement”, form a solid physical barrier.

Cement refers to the oil in the gaps between keratin cells. The cuticle composed of keratin is not completely tightly connected, but has many tiny gaps. There are “intercellular lipids” in these gaps, which are the “cement” that tightly connects the bricks.

▷▷Intercellular lipids are produced by living keratinocytes in the spinous layer. As cells divide, intercellular lipids are continuously released into the stratum corneum and act as cement.

▷▷Intercellular lipids are mainly composed of a variety of ceramides, cholesterol, and free fatty acids. They are extremely important members of the skin’s physiological lipids and are also important factors in maintaining a healthy skin barrier. Most skin care products on the market that focus on barrier repair also simulate physiological intercellular lipids to repair the skin.

So, what is the skin barrier used for?

This layer of skin barrier is hard-won for human evolution. Land mammals all have similar skin barriers. Most small animals have thick coats on their skin to protect themselves from damage caused by the outside world; while humans The skin barrier has evolved to become more complete and powerful:

The skin barrier is the body’s first line of defense. The skin barrier can resist external pollutants, such as air pollution particles, dust, and fibers. Allergens include: pollen, insect wing powder, dust mites, as well as various external stimuli such as ultraviolet rays, bacteria and viruses.

The fundamental core of skin care concepts such as “prevention is better than cure” and “sun protection is anti-aging” is often said to be “protection”, which means to reduce the occurrence of skin diseases and allow the skin to be less exposed to…”isolation” function to reduce direct contact with irritants.

A damaged barrier will inevitably be accompanied by the problem of too thin stratum corneum and reduced defense. The use of occlusive ingredients is a key point in the defense architecture of many barrier repair products. It provides the most basic sealing property to the skin with damaged barrier. On the one hand, it can prevent the skin from losing moisture. On the other hand, it can also replace the function of the stratum corneum, which is equivalent to isolating external irritants and preventing the skin from being damaged by the outside world.

There are many types of such ingredients. Here are some common examples:

Oils and oils: mineral oil, petrolatum, squalane, shea butter, isohexadecane, olive oil, cetyl alcohol ethylhexanoate, cetyl alcohol, caprylic acid capric triglyceride, etc. .

Silicon oil: cyclopentasiloxane, polydimethylsiloxane, etc.

Polymer gum: xanthan gum, biosaccharide gum, Sclerotinia gum, sodium polyglutamate, sodium hyaluronate, etc.

Waxes: beeswax, ozokerite, candelilla wax, etc.

For the skin, the protection of the stratum corneum is necessary; for skin care products that repair the barrier, occlusive protection is necessary. Therefore, when we choose barrier repair products, we should choose products with better moisturizing and sealing capabilities. Products that are especially refreshing and non-sensory will generally have weaker protective power.

However, some particularly oily skin types, acne-prone skin, especially patients with seborrheic dermatitis are not suitable for using products that are too moisturizing. You can choose a slightly lighter lotion/cream according to your actual situation. Don’t skip using moisturizing products at all just because you have a lot of oil.

3. Add physiological intercellular lipids such as ceramide/unsaturated fatty acids/cholesterol to consolidate the fragile stratum corneum and accelerate the recovery of physical barriers.

Physiological lipids such as ceramide/free fatty acid/cholesterol are different from the previously mentioned oils. Physiological lipids themselves are secreted by cell lamellar bodies and are highly compatible with the skin and have better penetration. ; These ingredients can penetrate deep into the bottom of the stratum corneum/surface of the granular layer, adhering to the stratum corneum, providing hydrophobic protection against chemical stimulation, defense against bacterial invasion, and certain anti-inflammatory capabilities.

To put it simply, without the presence of physiological lipids, the keratin cells in the stratum corneum will be looser and easier to fall off, which will more easily lead to barrier damage.

Although the skin itself can also secrete physiological lipids, the synthesis of lamellar bodies is insufficient when the barrier is damaged. At this time, exogenous supplementation of physiological lipids can maintain the normal function of lamellar bodies; achieve rapid The effect of direct barrier consolidation is equivalent to accelerating the barrier recovery cycle.

Ceramide: There are currently 12 types of ceramides discovered. But what is important for the skin is type 1/3/6 ceramides, which are also common ingredients in skin care products. In addition, phytosphingosine is also considered a ceramide, and it is the precursor of ceramide.

Cholesterol: Cholesterol, plant sterols.

Unsaturated fatty acids: linoleic acid, sublinoleic acid, and vegetable oils rich in linoleic acid and sublinoleic acid