is an independent complex and wise body. At the very bottom is the hypodermis, which consists of adipose tissue. It is this fabric that retains moisture. A little higher and closer to the surface is the dermis, which has special cells to absorb moisture from adipose tissue. Moisture goes freely up to the stratum corneum. This is the last layer before moisture comes out. In other words, the lipid layer of the skin is a barrier to the release of moisture.
It is clear that if something happens and it becomes thinner, then moisture freely leaves the skin and evaporates from the surface. Accordingly, very soon we will find a lack of moisture on our face. In violation of the lipid layer, the skin becomes dull and looks unkempt. The first wrinkles appear regardless of age, but due to a violation of the lipid layer.
- flabbiness,
- skin dehydration,
- saggy,
- dryness,
- peeling,
- fine network of wrinkles.
Do not forget that a broken lipid barrier can become a channel for the penetration of various bacteria into the skin. It causes skin irritation, as well as dermatitis, eczema, acne.
The lipid layer of the skin can be destroyed for a number of reasons:
- Washing the face with low quality soap and hot water.
- Uncontrolled adoption of ultraviolet baths.
- Frequent sudden changes in temperature.
- Physical stress, psychological experiences.
- Mechanical damage to the skin, for example, strong friction of the skin with a towel.
- Incorrectly selected cosmetics for the face.
The lipid barrier of the skin can be restored, and this is done easily and quickly with the help of a well-designed program of cosmetics. A damaged lipid mantle leads to dehydration of the skin, and an increase in its sensitivity to negative factors. It is simply necessary to restore the broken lipid layer. For this, various fatty products including some oils.
This is due to the fact that the main components of the lipid layer are: oil, phospholipids, fatty acids, ceramides and cholesterol. Thus, if you correctly select an oil of a similar composition, it is possible to quickly restore the lipid layer. Natural oils are rich in phospholipids and fatty acids. Phytosterols in the composition of natural oils can replace the natural cholesterol of the lipid layer. Moreover, natural oils contain antioxidants.
The most suitable oils for restoring the lipid layer are burdock, grape seed oil, and flaxseed. These tools are perfect even for owners oily skin.
Ideally, the oil should be applied to the skin before going to bed, and after 5-10 minutes, the skin should be blotted. paper napkin. If in the morning you find that your skin is very oily, then it is permissible to rinse your face with water at room temperature. Remember not to use hot water on your face. Oil should be applied to the skin daily for a month. Already after two weeks, you will notice how the skin of the face has become more elastic and elastic. Dryness and dehydration disappeared, they were replaced by a blush and a healthy glow.
In addition to natural oils, you can use ready-made creams and serums to restore the lipid layer of the skin of modern well-known manufacturers. Many of them deserve the closest attention. When choosing a tool, pay attention to the ruler. It is important that this remedy is from the line you are currently using. Be aware that these products may contain natural oils. Carefully study the composition to prevent the possibility of an allergic reaction to a rather expensive cosmetic product.
How to clean skin with oil
Oils do not need to be washed off before using. decorative cosmetics. Oil perfectly removes makeup. The whole procedure will take no more than 15 minutes. To do this, you will need oil, a towel or a cloth napkin.
Oil cleaning goes through several stages.
The oil is perfectly absorbed, nourishes the skin, so additional creams are not required after cleansing with oil. If you do not apply oil to the area of the eyes and lips, then add a couple of essential oils to it. It is very useful to add tea tree oil or lavender oil. For aging and dry skin, neroli and rose oils are suitable.
With regular cleansing of the skin with oil, you will see how inflammation, peeling disappear, the skin becomes fresh and smooth. The only downside to using oils is that it takes a little longer than usual. You will also need to change your towel often, and you should pay attention to the quality of the oils. good oil is not cheap.
You will notice the result of the restoration of the lipid layer very quickly by a clear improvement in the condition of your skin.
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The structural and functional health of the skin is largely related to the content and distribution of water in it. Dryness of the skin entails its easy permeability to toxic and sensitizing substances, contributes to the development of immune disorders and the formation of allergic inflammation. Violation of hydration of the stratum corneum of the epidermis is the main cause of pathological desquamation of the epithelium and xerosis. Since corneocytes are cells without a nucleus, dermatologists have not treated the stratum corneum with due attention until recently. But it turned out that by acting on the stratum corneum, one can not only achieve cosmetic effects, but also alleviate the symptoms of a skin disease, improve the result of drug treatment and improve the patient's quality of life.
The basis of skin care for skin diseases is “corneotherapy”, a system for restoring the functioning and integrity of the stratum corneum. In modern conditions, the line between cosmetics and medicines is gradually blurring due to the complication of the formulation of cosmetic preparations. Modern cosmetics can affect the physiological processes in the skin in the same way as a pharmaceutical drug does. The skill of a dermatologist is based on his ability to use various active and indifferent means of external therapy in therapy, achieving maximum success.
Numerous structures are involved in maintaining the water balance, which regulate the rate of transepidermal water loss and carry out the flow of water from the dermis to the epidermis. Obviously, for the full functioning of the skin, the supporting structure of corneocytes is necessary, and when it is disturbed, trans-epidermal water loss increases, which leads to epidermal hyperplasia and hyperkeratosis. The stratum corneum serves as a sensor for the underlying layers. In the epidermis, the water balance is controlled by the stratum corneum and the components of the stratum corneum of the epidermis (natural moisturizing factor, skin lipids, sebum and keratin).
The skin begins to dehydrate from the epidermis. This happens due to the fact that the epidermis is devoid of blood vessels that could replenish its moisture reserves, so the epidermis receives most of the fluid from the dermis. Until recently, it was believed that water seeps into the upper layers of the skin according to the law of perfusion. Free amino acids, formed during the destruction of the filaggrin protein, maintain a high osmotic pressure in corneocytes, which causes an influx of water, which is retained even at low humidity. environment. However, in last years It has been established that in maintaining a normal level of hydration of the epidermis, the mechanism of facilitated diffusion, i.e., the ingress of water molecules through water channels called aquaporins, is also important. Aquaporins are membrane proteins that form through pores on the surface of cells through which water passes, as well as small water-soluble compounds such as glycerol and urea. For the discovery of these proteins in 2003, a group of American scientists led by Peter Egre was awarded the Nobel Prize in Chemistry.
Having reached the surface of the skin, water tends to evaporate, but this is prevented by the stratum corneum. Despite the low water content in the stratum corneum - 15-20%, moisture retention is one of its main functions. The impermeability of the stratum corneum is due to the barrier properties of keratin, acylceramides and sebum. The epidermis is rather well permeable towards its surface and almost impermeable in the opposite direction. At the same time, water and water-soluble substances penetrate the epidermis with great difficulty, while fat-soluble substances are much easier. To appreciate the important role of the stratum corneum of the epidermis in maintaining moisture in the skin, it is necessary to clearly know its structure.
The stratum corneum is the end product of epidermal keratinocyte differentiation. V thin skin it consists of 15-20 layers of horny scales, with hundreds of layers thick. The scales are arranged in columns one above the other, and each scale in the projection covers 9-10 cells of the basal layer. The corneocyte has a 6-angled shape and each of the six sides is in contact with neighboring corneocytes, such a structure can be compared to a "quilt" . The horny layer of the epidermis has a unique structure, which is called “brick and mortar” (“brick and cement”), where the role of “bricks” is played by horny cells, and “cement” is played by intercellular lipids. On a transverse section, the stratum corneum appears loose, porous, but this is only an appearance. This impression is created due to the intercellular spaces, which make up a significant part of the stratum corneum. However, they are all filled with a special substance that sticks them together into an insurmountable barrier with acylceramide lipids, which belong to the class of sphingolipids, or ceramides. For the first time, sphingolipids were isolated from brain tissue, so they got their second name - ceramides - from the Latin word cerebrum (brain). Later it was found that ceramides are involved in the construction of the epidermal barrier, forming a lipid layer between the horny scales. Ceramide and phospholipid molecules have hydrophilic heads (water-loving fragments) and lipophilic tails (fat-loving fragments). In the aquatic environment, polar lipid molecules are independently grouped in such a way that the hydrophobic tails are hidden from the water, while the hydrophilic heads, on the contrary, are turned into the aquatic environment. If there are few such lipids (and if the mixture of lipids and water is shaken well), then balls (liposomes) are formed. This property of polar lipids is used in the cosmetic industry in the production of liposomes.
Ceramides are composed of the fatty alcohol sphingosine (forming the “head”) and one fatty acid (“tail”). If a fatty acid has double bonds, then it is called unsaturated, if there are no double bonds, then the acid is said to be saturated. Depending on which fatty acid is attached to the head of the ceramide, the lipid layers built from them are more or less liquid. The hardest (crystalline) lipid layers are formed by ceramides with saturated tails. How longer tail ceramide and the more double bonds it contains, the more liquid the lipid structures are. In addition to the intercellular lipid layers discussed above, lipids covalently associated with corneocytes were found in the stratum corneum. These are special long-chain ceramides, the tails of which are fatty acids with more than 20 carbon atoms in their chain. Long-chain ceramides act as rivets, holding adjacent lipid layers together. Thanks to them, the multilayer lipid layer does not exfoliate and is an integral structure. Ceramides have recently become very popular ingredients in cosmetics. The popularity of ceramides is due to the role they play in maintaining the integrity of the epidermal barrier.
Due to the presence of a multilayer lipid layer between the stratum corneum, the stratum corneum is able to effectively protect the skin not only from the penetration of foreign substances from the outside, but also from dehydration. Diffusion of water through dry semi-solid keratin plates glued into a continuous mass with ceramides is sharply reduced compared to liquid-filled living cells.
The main producers of intercellular cement are Orland's granules of cells of the granular layer. It is they who, by exocytosis, release their contents into the intercellular space, where it turns into lipid-rich intercellular cement with a lamellar structure. Thus, during keratinization, a hydrophobic epidermal barrier is formed, which not only prevents the penetration of harmful substances into the skin, but also participates in the regulation of water homeostasis in the dermis.
In addition to the mechanism of biomechanical impermeability of the stratum corneum, moisture-retaining structures maintain skin moisture.
epidermal water-retaining structures of the skin
1. Natural moisturizing factor (NMF)- this is a whole complex of organic molecules on the surface of corneocytes, which has the ability to bind water. It includes free amino acids (40%); sodium pyroglutamate (12%); urea (7%); ammonia, creatinine and other organic compounds (17%); magnesium (1.5%); potassium (4%); calcium (1.5%); sodium (5%); dairy and citric acid, chloride and phosphate ions (12%). Disruption of their balance entails a change in the composition of NMF and, as a result, the inability of the skin to retain moisture. The elasticity of the stratum corneum also depends on the amount of moisture associated with NMF. It has been proven that oily and normal skin has more NMF than dry skin.
The decrease in filaggrin synthesis, which is observed, in particular, in ichthyosis and atopic dermatitis, leads to a decrease in the content of amino acids in the composition of NMF and a decrease in the water-retaining capacity of the skin. Since a sufficient amount of moisture is required for the work of the enzymes involved in the hydrolysis of filaggrin, with the development of dryness of the stratum corneum, the formation of NMF amino acids also decreases. The result is vicious circle leading to chronic dryness of the skin.
The mineral composition of the natural moisturizing factor changes with the seasons, and it is these changes that cause the moisture content of the stratum corneum to decrease in winter. In particular, in winter, the level of potassium, sodium, chlorides and lactic acid salts significantly decreases in the stratum corneum.
With frequent washing with hot water and soap, amino acids and minerals can be washed out of NMF, which also leads to the development of xerosis. The most dangerous combination of "soaking", such as a long stay in a hot bath, and exposure to solvents and aggressive surfactants (surfactants). The danger of surfactants lies in the fact that they are able to interact with lipid films, since they, like polar lipids, have two sections - hydrophobic and hydrophilic, so they can be embedded in the lipid layer, turning to them with their hydrophobic "tails". In this case, the heads of surfactant molecules are grouped together so that hydrophilic, water-permeable areas appear in the lipid layer. Thus, the first consequence of the action of surfactants on the stratum corneum is the dehydration of lipid membranes, the so-called "Wash-Out-Effect" - the effect of washing out one's own lipids.
Prolonged exposure to anionic surfactants contributes to their deeper penetration up to the granular layer of the epidermis, which leads to the destruction of cell membranes of granulocytes - Orland granules, which are the main factory of intercellular lipids. As a result, the synthesis of lipids necessary for the adhesion of corneocytes is reduced.
That is why any cosmetic procedures, accompanied by "soaking" the skin, followed by cleansing, should be completed with the use of moisturizers based on NMF.
2. Epidermal intercellular lipids (lipid barrier)- consist of cholesterol, ceramides and unsaturated fatty acids (omega-3, omega-6), the amount of which is in a strictly defined proportion in relation to each other. If the corneocyte contains only 3% lipids, then the intercellular cement - 80%. According to biochemical data, the extracellular matrix contains: ceramides - ~40%, free fatty acids - ~20%, cholesterol and its esters - ~10%, cholesterol - ~15%, phospholipids - ~5%, squalene - ~10%. Cholesterol prevents excessive rigidity and fragility of the ceramide layer. Free fatty acids are located around ceramides in the lipid layer and help maintain the water-repellent function of the skin, protect the water-soluble components of the stratum corneum from leaching due to the formation of a water-oil emulsion. If this proportion changes, the lipid layer between the horny scales is broken and, as a result, the barrier function is broken, moisture evaporates more intensively. In an attempt to prevent excess moisture loss, the skin slows down the process of physiological desquamation, and cells begin to accumulate on the surface. Outwardly, this is manifested by excessive peeling, thickening of the stratum corneum, and a grayish tint. A striking example of such a process is seborrhea. With seborrhea, the concentration of linoleic acid in sebum decreases, which also leads to a violation of the integrity of the skin barrier and the emergence of an adaptive reaction in the form of an increase in the number of horny cells.
Among the lipids of the skin surface, epidermal lipids and lipids of the sebaceous glands are detected. Epidermal lipids make up the smaller part. The main components of epidermal lipids - free cholesterol and its esters - are formed during the breakdown of cell membranes of the stratum corneum. The epidermal lipids of the skin surface have been proven to have little effect on skin hydration, but represent a limiting membrane for water exchange.
Interestingly, the lipid composition of the stratum corneum is heterogeneous. The concentration of phospholipids decreases towards the surface, while the content of neutral lipids and ceramides, on the contrary, increases.
Changes in the composition of epidermal lipids occur in many diseases: atopic dermatitis, psoriasis, contact dermatitis, seborrhea, as well as in some physiological processes. For example, in atopic dermatitis, fatty acid metabolism is disturbed in the skin, and in ichthyosis, their decrease is observed (table). As a result, an inadequate protective hydrolipidic layer is formed, which also leads to transcutaneous water loss and facilitates the penetration of allergens and irritants.
3. Sebum. The functional significance of sebum is very high, standing out from the secretory part of the sebaceous glands, filling their excretory ducts and the mouths of the hair follicles, the secret is distributed along the grooves of the skin and unevenly covers almost its entire surface with a layer of 7-10 microns. In one week, a healthy person secretes 100-200 g of sebum secretion, and with seborrhea 300 g or more. On the surface of the skin, sebum mixes with the secretion of the sweat glands and emulsifies. Thus, a thin water-lipid emulsion film (sebum) is formed. The water-lipid mantle, like a wax coating, protects against excessive solar radiation, waterlogging, harmful environmental influences, infections, prevents the evaporation of water and releases glycerin, which binds water from the atmospheric air and keeps it close to the skin surface.
4. Keratin- the end product of the vital activity of the epidermis, characterized by resistance to mechanical, physical and chemical factors. According to some authors, keratin, like all proteins, is a colloid - it swells in water and binds water molecules.
If one or more water-retaining structures are violated (deficiency of components, structural changes, etc.), the water level in the stratum corneum drops. There is a violation of its structure, which entails a violation of the barrier properties. This means that the stratum corneum ceases to be an impenetrable barrier to water and its evaporation increases. Microorganisms, chemical factors of aggression, which further support irritation and inflammation of the skin, can more easily penetrate through the broken barrier. Dry skin is an invariable symptom of various skin diseases, such as atopic dermatitis, psoriasis, eczema, etc. In recent years, an unreasonable position among practitioners regarding the neglect of such an important aspect as skin care and restoration of its barrier function in patients has begun to be overcome. dermatoses. Therefore, in the second part of the article, we will talk not only about the auxiliary therapy of cosmeceuticals during an exacerbation, but also about a very important issue - fixing remission by actively restoring the integrity of the skin and its normal function with the help of medical and cosmetic products.
Literature
- Lomakina E. A. The role of the barrier function of the skin in the pathogenesis of some dermatoses // Contemporary Issues dermatovenereology, immunology and medical cosmetology. 2009, No. 2. S. 87-90.
- Kalyuzhnaya L. D. Atopic dermatitis and dry skin // Clinical Immunology. Allergology. Infectology. 2009, No. 1. S. 27-18.
- Tkachenko S., Hernandez E. Aquaporins in the regulation of skin water balance // Cosmetics and medicine. 2011, No. 2. S. 26-33.
- Myadlets O. D., Adaskevich V. P. Morphofunctional dermatology. M.: Medlit, 2006. 752 p.
- Margolina A. A., Hernandez E. I., Zaykina O. E. New cosmetology. M., 2002. 208 p.
- Koshevenko Yu. N. Human skin. T. 2. M.: Medicine, 2008. 754 p.
- Koshevenko Yu. N. Human skin. T. 1. M.: Medicine, 2006, 360 p.
- Modern external therapy of dermatoses (with elements of physiotherapy) / Pod. edited by N. G. Short. Tver: Provincial Medicine, 2001. 528 p.
- Cork M. J., Robinson D. A., Vasilopoulos Y. et al. New perspectives on epidermal barrier dysfunction in atopic dermatitis: gene-environment interactions // J Allergy Clin Immunol. 2006; 118(1):3-21.
- Dobrev H. Scientific Researches of the Union of Scientists // Series D. Medicine, Pharmacy and Dentistry. 2002; 1:107-10. Plovdiv.
- Norlen L., Nicander I., Lundh Rozell B. et al. Inter- and intra-individual differences in human stratum corneum lipid content related to physical parameters of skin barrier function in vivo // J Invest Dermatol. 1999; 112(1): 72-77.
- Roh M., Han M., Kim D., Chung K. Sebum Output as a Factor Contributing to the Size of Facial Pores // Br J Dermatol. 2006; 155(5): 890-894.
- Arabian E. R., Sokolovsky E. V. Dry skin. Causes of occurrence. Principles of correction // Journal of dermatovenereology and cosmetology. 2002, No. 1. S. 23-25.
- Hernandez E.I. Moisturizing the skin. Moscow: Firma Clavel LLC, School of Cosmetic Chemists LLC, 2007. 32 p.
Yu. A. Galliamova,doctor of medical sciences, professor
O. A. Barinova
RMAPO, Moscow
What is a lipid layer and why is it needed?
The outermost layer of the epidermis (skin) is called the stratum corneum. He got this name due to the shape of his cells - they are with spikes that look like horns. There are no nuclei in these cells, but there is a protein called keratin and nothing else. The stratum corneum protects our skin from the effects of the external environment and does not allow the water of our body to evaporate freely into space, that is, it saves us from dehydration. The surface of the stratum corneum is covered with a water-lipid mantle or lipid layer (barrier). Violation of this barrier by cosmetics and the environment leads to hypersensitivity, dryness and tightness, itching, allergies and flaking of the skin.
The lipid layer is a mixture of sebum, sweat and exfoliating particles of the stratum corneum. It may seem that this is a terribly unhygienic muck, but in fact, this is a very necessary thing for the health of our skin, and indeed the whole organism.
The lipid composition of the stratum corneum has nothing to do with sebum - neither in origin, nor in composition, nor in structure. Sebum is produced in the cells of the sebaceous glands. The stratum corneum lipids are synthesized in keratinocytes as they mature.
The lipids (fats) of the protective layer are organized into stacked bilayers. These bilayers do not allow substances from the outside to penetrate into the skin, but allow oxygen to pass through.
Now for a bit of biology history.
Our ancestors, well, sooooo distant, lived in the water. Their skin separated the outer water from the inner. When they crawled out (or were they thrown out by a wave?) On land, a mechanism was needed to separate the internal water and the gaseous environment of the air. This role was taken over by the lipid layer of the skin. The composition of the lipid layer is unique to the human body - it exists only on the skin. The pH of our lipid layer is in the range of 4.5-5.5. This is important indicator, because a change in Ph to a lower or higher side destroys the lipid layer. Any cosmetics, or rather the emulsifiers included in their composition, also partially destroy the lipid layer.
It turns out, washing, using creams and cosmetics, we harm our skin?
Yes and no. Yes, because any interference with natural processes affects our body in an unpredictable way. No, because we do not live in a natural environment and must adapt to its conditions. Our task in the process of skin care is to make sure that there are more pluses from care than minuses.
To begin with, let's deal with cleansers and their effect on the lipid layer.
Cleansing agents.
Solid soap.
The worst possible choice. Its Ph is shifted to the alkaline side, that is, more than 7. It actively removes not only dirt, but also the lipid layer itself, from which the skin becomes dry and defenseless against the attack of bacteria and viruses. The natural protection of the skin from sunlight decreases, the likelihood of age spots increases.
Liquid soap , it is also a hydrophilic cleaner or hydrophilic emulsion. Synthetic detergent, which includes petroleum products, oils, fats. Due to the presence of free fatty acids in it and the absence of alkali, it has less irritant effect on the skin. Hydrophilic cleaners consist of an aqueous and oily phase, to dissolve and remove various kinds pollution. The pH of such a product is 5.5, and corresponds to the Ph of the skin. Almost all hydrophilic cleaners contain SLS (sodium laurel sulfate), which acts quite aggressively on the skin, removing fats. Only expensive cosmetic companies produce cleansing emulsions without SLS.
Sometimes SLES (sodium loret sulfate) is used, this is when another ester chain is added to the SLS. Products containing SLES lather well and are less aggressive on the skin.
Hydrophilic emulsions with the addition of free fatty acids, this is what is sold with the inscription "Moisture - 25%". The problem is that moisturizing is actually out of the question. Such products simply leave a protective film on the skin, instead of a washed off lipid layer, to prevent water from evaporating.
What to do? Don't wash?
You will have to wash your face, because in the conditions of the city, the “periodic table” that settles on our skin in a day destroys the lipid barrier faster than any soap.
However, I do not get tired of repeating, washing - washing - strife. The most thorough washing for oily skin requires the use of soap with salicylic acid - it has an antiseptic effect, exfoliates dead cells of the stratum corneum and dries inflamed areas. Morning wash for oily skin without significant problems, includes the use of lotion for oily skin and water. Or just lotion.
For normal skin, the washing emulsion is used only in the most thorough washing. In the morning and just before going to bed, it is enough to wipe the skin with an alcohol-free lotion.
For dry skin - when thoroughly washing, use milk, and in the morning and before bedtime lotions that do not contain alcohol.
What else is on the shelves besides soap?
Soapy foaming cream
- Designed to take care of problematic skin. Just like shaving foam, it is based on stearin soap. Usually there are added substances that have an anti-inflammatory effect.
Foams for washing.
Remember, the more transparent the consistency of the foam, the more aggressive it is. Foam for dry skin cannot be transparent!
Gel without soap.
As a rule, its base is glycerin, and it is intended for dry and sensitive skin.
Cleansing milk, cream, cream.
Use only for normal to dry skin. There is no "milk for oily skin" no matter what the manufacturers write there. Cosmetic milk, cream, etc. include mineral oil. Don't let yourself be fooled. There are no minerals in this oil. This is an oil product that leaves the same film on the skin that remains on the surface of the ocean after a tanker accident. It kills all living things because it cuts off access to oxygen.
Don't be scared. Mineral oil perfectly removes any dirt. But it must be washed off very carefully. Not completely washed off milk on oily skin will interfere with normal excretory processes and will quickly lead to the formation of comedones and blackheads.
But for dry skin, this is an excellent cleanser, without aggressive components that destroy the lipid layer, but you still need to wash off the milk thoroughly.
Lotions.
The higher the alcohol content of the lotion, the more oily skin it is intended for. Lotion for dry skin should not contain alcohol at all. And if you have normal skin try to use a lotion that does not contain alcohol.
Many lotions are based on propylene glycol and glycerin. Glycerin has one unpleasant property, when the air humidity is above 65%, it draws water from the skin. Therefore, at high humidity, we replace lotions with glycerin ... with ordinary milk, diluted with mineral water. All sorts of horrors are also told about propylene glycol, but I will not dwell on them in detail, because. cosmetics without the content of this solvent are very expensive. If you are strongly against propylene glycol, then it is better to use home remedies for washing.
Tonics and toilet water.
They are not cleansers. Their task is to restore the pH of the skin and/or have some specific effect. For oily skin - antiseptic and anti-inflammatory, for normal and dry skin - soothing or tonic.
Very good for maintaining the lipid layer if your remedies include:
- instead of propylene glycol - silicones - cyclomethicone, simethicone and dimethicone.
- instead of mineral oil - vegetable oils(jojoba, avocado, mikademii) and vegetable wax.
- instead of SLS and SLES - proteins of milk, soy, algae and the latest achievement - phospholipids, which are related to skin lipids.
We will be careful in choosing the means to cleanse the skin and preserve the lipid layer.
Recommend to people with dry, sensitive skin from the Swiss brand Method Cholley, it contains all the components that restore the lipid barrier of the skin and eliminate the feeling of tightness and skin sensitivity!
Sometimes, when our skin experiences problems, it seems to us that we need some special and very expensive cream to restore normal condition. But this article is about how, knowing the elementary laws of nature and human physiology, you can create a simple, inexpensive and unique recipe that can completely restore the skin and give it a moisturized, smooth and healthy look.
We always expect a miracle from each new brand-name cream announced, and this expectation boils down to one thing - we need smooth, fresh and healthy skin. But even those people who do not have obvious skin diseases can hardly say that their skin condition is always perfect. We are “tormented” by either dryness, or peeling, or redness, or obvious dullness - “fatigue” of the skin.
At the root of all these problems is skin lipid barrier damage , and, accordingly, the solution to all these problems will be the restoration of the lipid barrier of the skin.))) Let's figure it out.
What is a lipid barrier?
In a very simple way, this is the uppermost part of our skin, which we observe every day, and which consists of flat scales (bricks, "dead" keratinocytes that have completely gone through their entire life cycle from the basal skin layer to the uppermost - stratum corneum), glued together by fat cells (lipids). You can imagine this for yourself in the form of bricks glued together with cement, and forming a strong, waterproof wall.
Why does the stratum corneum need to be waterproof and why are lipids needed?
Our skin is a fairly complex and “wise” organ. At its very "bottom" is the hypodermis, consisting of adipose tissue, which accumulates and retains moisture contained in body tissues. Slightly higher and closer to the surface, the dermis begins, which has special cells that absorb moisture from the hypodermis, like sponges, and this moisture goes unhindered further up, into the epidermis, right up to the stratum corneum. And just the stratum corneum (corneocytes glued together with fatty lipids) is the last layer and at the same time a barrier for further moisture to come out already, i.e. its evaporation.
Accordingly, if something happens to the lipid "cement" and it becomes thinner or even destroyed (for example, due to exposure of the skin to alkali in the form of soap), water, which is an integral part of healthy, dense and radiant skin, evaporates through loose, loose scales. stratum corneum, and we have the following visible problems on the face:
obvious dehydration of the skin
laxity
decreased skin elasticity (sagging)
peeling
dryness
fine network of wrinkles
And also, through the broken lipid barrier, various substances (bacteria, toxins, etc.) can penetrate the skin, which can cause irritation, such as:
eczema
dermatitis
acne
The lipid layer (“cement”) consists of free fatty acids (mainly oleic and linoleic), ceramides (up to 50% in the skin) and cholesterol.
How can the barrier function of the skin be broken?
Yes, very easy.
For example, washing your face frequently with hot water and soap or by special means for washing, with the addition of surfactants.
Or with the help of various aggressive environmental factors that cause peroxidation of these same skin lipids (summer insolation, solarium use, immune reactions).
Or because of the disturbed production of lipids by the body as a result of the transferred physical stress.
What is important for us to know.
lipid barrier easy and very fast restored from the outside, through well-composed cosmetics.
Free fatty acids can be replaced with vegetable triglycerides (scientifically proven) , which is extremely important for restoring the broken lipid barrier in oily and inflamed skin.
And now, we offer you to prepare the following simple and inexpensive cream to restore a healthy and blooming skin after summer holidays, hard and nervous working days, and simply - to restore the beauty of the skin after various inflammations. Has no age restrictions.
We have prepared two recipes: for oily skin (and with acne) and for normal and dry skin.
The sources of fatty acids are vegetable triglycerides and vegetable oils rich in oleic and linoleic acids, the sources of ceramides are "Ceramide Complex", and the source of cholesterol is natural lanolin. Plus, each recipe is sure to add ingredients from the Natural Moisturizing Factor in order to restore transepidermal moisture loss in the skin.
Revitalizing cream-serum for oily skin and skin with acne (50 ml).
Phase 1 (oily)
Phase 2 (water)
Phase 3 (active)
- 3 ml
- 2.5 ml
- 30 drops
Cooking.
In a water bath, heat Phase 1 and Phase 2 in separate refractory cups until the components of Phase 1 (oils and emulsifiers) are completely melted and become a single homogeneous oily liquid.
Mix both phases together and start beating with a mixer until an emulsion is formed, and continue beating for a short time (5-10 minutes).
When the emulsion has cooled slightly, add the Phase 3 components (assets) to it one by one and continue to beat for a few more minutes. Transfer the emulsion to a cosmetic jar and chill the cream in the refrigerator.
With the help of this cream, you can easily restore the broken lipid barrier of the skin and make up for the loss of moisture that was caused by insufficient skin care during the summer holidays. Literally in a few days it will already become noticeable how the skin will become smooth, elastic, perfectly hydrated, and therefore blooming and healthy.
Advice! In the cream, if desired, you can add. It will be an additional moisturizing and soothing asset for the skin, and a pleasant subtle and soothing fragrance for your sense of smell and comfort, because essential oils- this is the main healing agent in aromatherapy, and we combine aromatherapy and natural cosmetology in their recipes for beautiful and youthful skin.
The molecules of phospholipids and glycolipids are amphiphilic, that is, the hydrocarbon radicals of fatty acids and sphingosine are hydrophobic, and the other part of the molecule, formed from carbohydrates, a phosphoric acid residue with choline, serine, ethanolamine attached to it, is hydrophilic. As a result, in the aquatic environment, the hydrophobic regions of the phospholipid molecule are displaced from the aquatic environment and interact with each other, and the hydrophilic regions are in contact with water, resulting in the formation of a double lipid layer of cell membranes (Fig. 9.1.). This double layer of the membrane is permeated with protein molecules - microtubules. Oligosaccharides are attached to the outer side of the membrane. The amount of protein and carbohydrates in different membranes is not the same. Membrane proteins can perform structural functions, can be enzymes, carry out transmembrane transfer of nutrients, and can perform various regulatory functions. Membranes always exist as closed structures (see Figure 9.1). The lipid bilayer has the ability to self-assemble. This ability of membranes is used to create artificial lipid vesicles - liposomes.
Liposomes are widely used as capsules for the delivery of various drugs, antigens, enzymes to various organs and tissues, since lipid capsules are able to penetrate cell membranes. This allows you to direct medicinal substances exactly to the address in the affected organ.
Fig.9.1. Diagram of a cell membrane made from a lipid bilayer. Hydrophobic regions of the lipid molecule are attracted to each other; hydrophilic regions of the molecule are located on the outside. Protein molecules permeate the lipid bilayer.
lipid metabolism
In the body, neutral fats are in 2 forms: storage fat and protoplasmic fat.
The composition of protoplasmic fat includes phospholipids and lipoproteins. They are involved in the formation of the structural components of cells. The membranes of cells, mitochondria and microsomes consist of lipoproteins and regulate the permeability of individual substances. The amount of protoplasmic fat is stable, and does not change depending on starvation or obesity.
Spare (reserve) fat - it consists of triacylglycerols of fatty acids - is located in the subcutaneous adipose tissue and in the fat depots of internal organs.
The functions of reserve fat are that it is a reserve source of energy available for use during the fasting period; it is an insulating material from the cold, from mechanical injuries.
It is also important that lipids, decomposing, release not only energy, but also a significant amount of water:
During oxidation of 1 gram of protein, 0.4 g is released; carbohydrates - 0.5 g; lipids - 1 g of water. This property of lipids is of great importance for animals living in desert conditions (camels).
Digestion of lipids in the gastrointestinal tract
In the oral cavity, lipids are only mechanically processed. The stomach contains a small amount of lipase, which hydrolyzes fats. The low activity of gastric juice lipase is associated with an acidic reaction of the contents of the stomach. In addition, lipase can only affect emulsified fats; there are no conditions in the stomach for the formation of a fat emulsion. Only in children and monogastric animals does gastric lipase play an important role in lipid digestion.
The intestine is the main site of lipid digestion. In the duodenum, lipids are affected by liver bile and pancreatic juice, while intestinal contents (chyme) are neutralized. Fats are emulsified by bile acids. The composition of bile includes: cholic acid, deoxycholic (3,12 dihydroxycholanic), chenodeoxycholic (3,7 dihydroxycholanic) acids, sodium salts of paired bile acids: glycocholic, glycodeoxycholic, taurocholic, taurodeoxycholic. They consist of two components: cholic and deoxycholic acids, as well as glycine and taurine.
deoxycholic acid chenodeoxycholic acid
glycocholic acid
taurocholic acid
Bile salts emulsify fats well. This increases the area of contact of enzymes with fats and increases the action of the enzyme. Inadequate synthesis of bile acids or delayed intake impairs the effectiveness of the enzymes. Fats are usually absorbed after hydrolysis, but some of the finely emulsified fats are absorbed through the intestinal wall and pass into the lymph without hydrolysis.
Esterases break the ester bond between the alcohol group and the carboxyl group of carboxylic acids and inorganic acids (lipase, phosphatases) in fats.
Under the action of lipase, fats are hydrolyzed into glycerol and higher fatty acids. Lipase activity increases under the influence of bile, i.e. bile directly activates lipase. In addition, Ca ++ ions increase lipase activity due to the fact that Ca ++ ions form insoluble salts (soaps) with released fatty acids and prevent their overwhelming effect on lipase activity.
Under the action of lipase, at the beginning, ester bonds are hydrolyzed at α and α 1 (side) carbon atoms of glycerol, then at the β-carbon atom:
Under the action of lipase, up to 40% of triacylglycerides are cleaved to glycerol and fatty acids, 50-55% is hydrolyzed to 2-monoacylglycerols, and 3-10% is not hydrolyzed and absorbed as triacylglycerols.
Feed sterides are broken down by the enzyme cholesterol esterase to cholesterol and higher fatty acids. Phosphatides are hydrolyzed under the influence of phospholipases A, A 2 , C and D. Each enzyme acts on a specific lipid ester bond. The points of application of phospholipases are shown in the diagram:
Phospholipases of the pancreas, tissue phospholipases are produced in the form of proenzymes and are activated by trypsin. Phospholipase A 2 of snake venom catalyzes the cleavage of the unsaturated fatty acid at position 2 of phosphoglycerides. In this case, lysolecithins with hemolytic action are formed.
phosphatidylcholine lysolecithin
Therefore, when this poison enters the bloodstream, severe hemolysis occurs. In the intestine, this danger is eliminated by the action of phospholipase A 1, which quickly inactivates lysophosphatide as a result of the cleavage of a saturated fatty acid residue from it, turning it into inactive glycerophosphocholine.
Lysolecithins in low concentrations stimulate the differentiation of lymphoid cells, the activity of protein kinase C, and increase cell proliferation.
Colamine phosphatides and serine phosphatides are cleaved by phospholipase A to lysocolamine phosphatides, lysoserine phosphatides, which are further cleaved by phospholipase A 2 . Phospholipases C and D hydrolyze choline bonds; colamine and serine with phosphoric acid and a phosphoric acid residue with glycerol.
Lipid absorption occurs in the small intestine. Fatty acids with a chain length of less than 10 carbon atoms are absorbed in non-esterified form. Absorption requires the presence of emulsifying substances - bile acids and bile.
Resynthesis of fat, characteristic of a given organism, occurs in the intestinal wall. The concentration of lipids in the blood within 3-5 hours after ingestion of food is high. Chylomicrons- small particles of fat, formed after absorption in the intestinal wall, are lipoproteins surrounded by phospholipids and a protein coat, inside they contain molecules of fat and bile acids. They enter the liver, where lipids undergo intermediate metabolism, and bile acids pass to the gallbladder and then back to the intestines (see Figure 9.3 on page 192). As a result of this circulation, a small amount of bile acids is lost. It is believed that the bile acid molecule makes 4 circuits per day.
