Used in medicine and cosmetology, the name of the lipid structures of the stratum corneum of the epidermis, designed to emphasize their barrier (protective) function.
The main task facing the barrier is to ensure the integrity of the skin. Bacteria, viruses and other exogenous substances, as a rule, enter the body through the intercellular spaces of the stratum corneum. These gaps cover the lipids.
The lipids of the stratum corneum has nothing to do with sebum. They differ in composition, structure, and origin. Sebum is produced in the cells of the sebaceous glands. The stratum corneum lipids are synthesized in keratinocytes as they mature. At the level of the transition of the granular layer to the stratum corneum, these lipids (more precisely, their precursors) are released into the intercellular space, where, with the participation of enzymes, the enzymatic assembly of lipid layers (membranes) begins. The lipid barrier of the stratum corneum consists of several such extended and continuous layers superimposed on each other. Between the layers are water molecules that are in constant motion, moving from the lower to the upper layers, and evaporate when they reach the surface of the skin.
The lipid barrier consists of three types of lipids: ceramides, free fatty acids and cholesterol.
Ceramides(sphingolipids) form the basis of the lipid layer between the horny scales. These are complex lipids, consisting of several blocks - fatty alcohol sphingosine or phytosphingosine (forms a hydrophilic "head") and one fatty acid (lipophilic "tail"). Among ceramides, long-chain type 1 ceramides, which include linoleic acid, stand out. These ceramides pierce adjacent lipid layers and bind them into a single structure. With a lack of linolenic acid, the synthesis of ceramides 1 suffers, respectively, the lipid layer of the stratum corneum loses its integrity and disintegrates. The consequence of this is dry skin and other symptoms associated with it (flaking, hypersensitivity, irritation, etc.).
Fatty acid are present in the lipid barrier of the stratum corneum both in the composition of ceramides and in the free state. An important characteristic fatty acids is their saturation, i.e. the presence of double bonds. Fatty acids containing one unsaturated bond are called monounsaturated, two or more - polyunsaturated. The quantity and quality of unsaturated fatty acids (both free and included in complex lipids) determines the viscosity of the fatty medium (the more polyunsaturated fatty acids, the more liquid it is). To maintain the integrity of the lipid layers of the skin and their physical and chemical properties the right balance between saturated and unsaturated fatty acids is needed.
Cholesterol– important component not only the lipid barrier of the stratum corneum, but also the membranes of all living cells. Unlike ceramides, cholesterol does not have a hydrophilic site and is a lipophilic molecule. It is localized between hydrophobic tails and does not come into contact with water. Cholesterol regulates the viscosity of the lipid membrane and helps maintain its integrity and continuity.
Literature:
1. Grabeklis S.A. DMAE and (myo) fibroblasts. Mesotherapy 2009; №6-7
2. Deev AI How to overcome the horny shield of our skin? Mesotherapy 2010; №10 / 02
3. Zorina A., Zorin V., Cherkasov V. Dermal fibroblasts: diversity of phenotypes and physiological functions, role in skin aging. Aesthetic Medicine 2012; volume XI; #1
4. Nino M., Calabro G., Santoniani P. Non-invasive transdermal delivery of active substances: practical use and promising developments. Cosmetics & Medicine 2010; #4
We offer a recipe for a simple and inexpensive cream to restore healthy and blooming skin after summer holidays, hard and nervous working days, and simply - to restore the beauty of the skin after various inflammations.
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. A little 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 further upwards, 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 barriereasy and very fastrestored from the outside, through well-composed cosmetics.
Free fatty acidscan 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 propose to prepare for you the following simple and inexpensive cream to restore a healthy and blooming appearance of the 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.
Sources of fatty acids are plant triglycerides and vegetable oils, rich in oleic and linoleic acids, sources of ceramides - "Ceramide Complex", and a source of cholesterol - 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)
.Plant Triglycerides- 15% (7.5 ml)
.Lanolin - 2% (1 g)
.Cetyl alcohol - 2% (1 g)
.Emulsifier "Basic"- 5% (2.5 g)
Phase 2 (water)
Water - 60% (30 ml)
.vegetable glycerin- 2% (1 ml)
Phase 3 (active)
.Ceramide complex- 6% (3 ml)
.NUV - 5% (2.5 ml)
.Ac.Net - 2% (3 ml)
.Lactic acid-1% (10 drops)
Revitalizing cream-serum for normal and dry skin (50 ml).
Phase 1 (oily)
.Cannabis oil - 4 ml
.Cocoa butter - 2 g
.Lanolin - 2 g
.Emulsifier "Basic"- 2.5 g
.Cetyl alcohol - 1 g
Phase 2 (water)
Water - 30 ml
.vegetable glycerin- 1 ml
Phase 3 (active)
.Ceramide complex- 3 ml
.NUF - 2.5 ml
.GLYCO - REPAIR - 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 Bulgarian lavender essential oil . 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 with pleasure and great benefit in our recipes for beautiful and young skin.
Fats (lipids) and fat-like substances occupy one of the leading places in the compositions of modern cosmetics, both intended for skin and hair care, and in decorative cosmetics. Fats are esters of fatty acids, or otherwise, triglycerides of saturated and unsaturated fatty acids. This chemical composition largely determines the ease of their penetration into the hair follicle (hair root) and into the upper layers of the epidermis - the outer layer of the skin. Fats and fat-like substances have a greater dermatological value and biological activity, which is why they are a good basis for cosmetics. Plant and animal organisms contain mainly neutral fats, the proportion of free fatty acids in natural fats and oils is relatively small. The more free fatty acids in natural fat or oil, the higher its ability to penetrate into the deeper layers, and accordingly, it is more valuable as an active ingredient. Depending on the chemical composition, fat may exhibit certain physical properties: Saturated fatty acids predominate in solid fats, while liquid oils consist of triglycerides of unsaturated fatty acids. According to scientists, the lipid composition of the epidermis has a fundamental impact on the condition of the skin as a whole; dry skin and flaking is clear signs lipid deficiency.
At the same time, the severity of pathological processes directly depends on the magnitude of lipid imbalance. Mild disorders can be eliminated with the help, since the fats and oils contained in the composition of such products very effectively affect the physiological processes in the skin. Lipids, along with proteins and carbohydrates, are the building material for living organisms; V in large numbers they are contained in the membrane (cell wall). The upper layer of the skin, in which there are no blood vessels, quickly dies off without the support of lipids, only the presence of fats can maintain a healthy state upper layer skin and ensure its normal functioning.
Fat softens the skin, increases its elasticity, makes it soft and tender; impregnating the top layer of the skin, it reduces the loss of moisture, while softening the epithelium; lipid intake effective method prevention of wrinkle formation. Lipids protect the body as a whole from the aggressive effects of the external environment; their role in the processes of thermoregulation is extremely great: in case of lipid imbalance, the skin undergoes excessive hypothermia or overheating. In addition, with a lipid imbalance, metabolism is disturbed, there is a narrowing of the glands and blood vessels; The protective properties of fats also extend to nerve endings exposed to aggressive external stimuli. Lipids also have hygienic functions: they dissolve the rest of the secretion of sweat and sebaceous glands that accumulate on the surface of the skin. In order for natural fat to exhibit biological activity, it must be absorbed by the skin, that is, it must be broken down into its constituent parts, from which the substances necessary for the body are then synthesized. Triglycerides entering the skin with cosmetics are sources of fatty acids, from which, for example, ceramides are synthesized - important lipid components of the cell membrane; phospholipids - esters of polyhydric alcohols and higher fatty acids, etc. Thus, the properties cosmetic oils completely determined by the composition of the triglycerides of which they are composed; most often, the skin lacks the so-called essential fatty acids, which are not synthesized by the animal body and the absence of which causes symptoms of fatty acid deficiency, i.e. they are really essential - these are mainly linolenic and linoleic acids.
The skin is the outer covering human body, carrying out its relationship with the environment. The skin is the largest organ of the human body, multifunctional and extremely complex in structure. It performs many functions, and the performance of these diverse functions takes place in constantly changing, often harsh and aggressive conditions under the influence of various factors environment. What is the structure of human skin, and what is the role of the lipid layer?
Skin structure: the life cycle of keratinocytes
The unique structure of the skin provides the above functions. The skin is made up of three layers: epidermis, dermis, and subcutaneous fat. Each of them has a special structure. Only the epidermis is available for direct exposure to cosmetics, and mainly its stratum corneum.
The main cell of the epidermis is the keratinocyte. The lowest layer of the epidermis is called the basal; keratinocytes of this layer are in a state of constant division. As they mature, keratinocytes move up to the surface of the skin, and the cells move in a single layer, which makes it possible to single out separate layers in the epidermis depending on the stage of development, or rather, on the stage of “dying” of keratinocytes.
The main functions of the skin:
- barrier;
- protective;
- thermoregulatory;
- receptor;
- endocrine;
- excretory;
- respiratory;
- immune;
- vitamin-forming;
- social.
What is the lipid barrier of the skin?
The upper layer of the epidermis is called the horny and is represented by corneocytes - cells that are filled with keratin protein and have lost the nucleus, as well as cell organelles. The sheath of corneocytes is called horny envelopes. They have the shape of a hexagon, fit tightly to each other, connecting with special protrusions - corneodesmosomes.
The space between corneocytes is filled with a lipid-protein structure (the so-called lipid barrier of the skin), which “glues” the corneocytes together. This structure of the skin ensures the integrity of the stratum corneum. The lipids of this barrier consist of ceramides, cholesterol and its esters, and free fatty acids.
For healthy skin with good barrier properties, the proportion of ceramide/cholesterol/free fatty acids is 1:1:1. A change in this proportion leads to a violation of the entire structure of the lipid barrier and, as a result, to a weakening of the barrier function of the stratum corneum as a whole.
The lipid barrier is formed by alternating layers of lipids and water.
What are the functions of the layers of the skin
Despite the fact that the stratum corneum consists of dead cells, it is metabolically active due to the work of numerous enzymes. The stratum corneum is a reliable barrier to the path of various substances. The corneocytes themselves are practically impermeable, the passage of substances is possible only through the lipid layer. This layer is impermeable to water-soluble compounds, and the passage of large molecules (for example, proteins or polysaccharides) is also difficult. The structure of the skin, in particular the stratum corneum, provides selective permeability of the skin for various substances.
The epidermis and dermis are permeated with free nerve endings that have special receptors for histamine and are highly sensitive to it.
Histamine is secreted by mast cells with the most minor changes in the extracellular environment. The result is an itching sensation. This structure of the skin provides an immediate reaction skin to an allergenic agent.
By blocking the penetration of water-soluble compounds, the stratum corneum also effectively protects the skin from excessive moisture loss, that is, from dehydration. Fat-soluble compounds not only pass through the epidermal barrier, but can also change its permeability to other substances. To increase the permeability of lipid layers, unsaturated fatty acids are added to the composition of external medicinal and cosmetic products, which are embedded in the lipid layer and reduce its viscosity.
It is important for cosmetologists and dermatologists to know the structure of the skin in order to understand the ways and means of eliminating skin problems without harming its cells.
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 an important indicator, because a change in Ph to a lower or higher side destroys the lipid layer. Any cosmetical tools, 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.
Worst of options. 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, including petroleum products, oils, fats. Due to the presence of free fatty acids in it and the absence of alkali, it has a less irritating 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 cleansing for oily skin requires the use of soap with salicylic acid- it has an antiseptic effect, exfoliates dead cells stratum corneum and dries the 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 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, mikademiya) 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!
