Redness, itching, rashes, have you ever had these skin problems? At a microscopic level, skin barrier function has become disordered along with skin problems. What does a normal skin barrier look like? What happens to an abnormal skin barrier? Let's take a look.
The outermost barrier of the skin is the stratum corneum, which is involved in multiple defensive functions of the skin, but the most important one is the prevention of fluid and electrolyte loss, i.e. the osmotic barrier function. The osmotic barrier function is a function achieved by the multilayer bilayer structure of intercellular lipids arranged in the stratum corneum, which combines both the osmotic barrier and protective effects. The protective effects of the stratum corneum are as follows.
- Permeability barrier
- Induction of inflammation
- Adhesion
- Antimicrobial barrier
- Mechanical protection (impact, crush)
- Protection against harmful chemicals
- Hydration
- UV barrier
- Neurosensory
When the skin is excessively attacked by the above-related factors, the feedback action made by the skin barrier is unable to meet the energy component consumed to defend against it and the transcutaneous water loss increases leading to dryness and consequently damage.
In fighting against external aggressions, the epidermis forms a coordinated compensatory mechanism to rapidly restore normal barrier function through high lipid synthesis and accelerated lipid secretion, a process that consumes replenishment of lipids in the stratum corneum.
This structure is referred to as the "brick wall structure", which is the skin structure we are most familiar with. The brick wall structure is composed of "bricks" (apoptotic keratinocytes) tightly bonded to "cement" (physiological lipids).
The lipid composition of the lamellar membrane is derived from the degradation of the intercellular matrix in the stratum corneum mostly by components secreted by the lamellar vesicles in the epidermis. Ceramides, phospholipids, free fatty acids, and cholesterol.
These components will form the lamellar membrane required for the permeability barrier, a unique bioactive membrane with the following typical characteristics.
- Extreme hydrophobicity.
- The weight percentage of lipids in the stratum corneum is equal to the number of layers of the lamellar membrane in the intercellular stroma
- The molar ratio of ceramide: cholesterol: free fatty acids is 1 Ceramides, i.e. acetyl ceramides, together with linoleic acid, hold the two layers of the lamellar membrane tightly together.
Conditions for lipid synthesis with physiological and non-physiological lipids, i.e. endogenous and exogenous lipids.
Non-physiological lipids are not products of the lipid secretion pathway of the granulosa cells and cannot penetrate below the stratum corneum, but penetrate the keratinocytes, forming hydrophobic non-lamellar structures that replace the endogenous lamellar bilayer.
These typical non-physiological lipids, which include not only petrolatum but also other substances such as lanolin, squalene, caprylic/capric triglycerides, and some other hydrocarbons, mainly act as a water diffusion barrier, capable and reducing water dispersion, but not completely preventing it.
Physiological lipids prevent water diffusion, on the other hand, have a lag because physiological lipids need time for cytokinesis, secretion, and then the formation of lamellar structural membranes that can increase or supplement the biosynthesis of endogenous paper.
The advantage of non-physiological lipids is that they do not distinguish between types of barrier damage, but can obtain similar repair effects and, although not a component of lamellar membranes has some other benefits in some cases, such as relief of inflammation, moisturization, water repellency, and barrier.
Therefore, depending on the variability of the mechanism of action, physiological and non-physiological lipids are complementary and can be used in combination with formulations.
When the skin barrier is lost, what are the ways to repair it?
1. reducing the use of cleansing and efficacious skin care products to reduce irritants.
2. supplementation of non-physiological lipids: use or multiple non-physiological lipids to temporarily restore barrier function, but not to correct specific skin function abnormalities; e.g. single component products such as petroleum jelly.
3. dressings: such as thick cream products, collagen dressings, etc.
NEUTRIHERBS COLLAGEN CREAM is mild in composition and rich in collagen, panthenol, and other repairing ingredients.
There are various factors for skin barrier damage, and frequent use of highly concentrated or potent products in the skincare process can also cause skin barrier damage and lead to uncoordinated physiological lipid secretion in the skin.
Therefore, skin care products should be selected in conjunction with your skin condition, with priority given to moisturizing effects.