It is widely known that skin´s own hyaluron is a precious molecule keeping our skin hydrated as it is a powerful humectant (attracting and binding water), hence giving the skin a natural plumpness and bounce. What many don´t know is that skin´s own hyaluronic acid content needs to be replenished continuously, as it´s half-life is only several hours up to one day 1. It´s degradation is fastened by 2 different pathways: an external influence via free radical activity or physical degradation and an internal pathway via enzymatic or biological degradation by a family of enzymes called hyaluronidase or abbreviated HYAL.

There are 6 different ones identified and HYAL 1 is the most active one. HYAL 1 “cuts” large size hyaluron molecules (the most capable of binding water) into smaller molecules, which are eliminated even faster. One of the strategies to maintain skin´s own hyaluron content is to inhibit the HYAL enzymes, especially HYAL1. Comparing photo-exposed skin to photoprotected skin showed significant increase in the expression of L-HA (low molecular weight HA) which are smaller or broken hyaluronic acid molecules. An increase of degradated hyaluron was associated with a significant expression of HYAL-1 (2)..UV, ROS or free radical activity leads to the activation of hyaluronidase (3,4).

You may now wonder how it is possible that hyaluron filler injections can have a lasting effect of several months or even longer than a year. This is because in those injectable gels the hyaluron molecules are stabilized to protect them from the impact of free radicals and HYAL enzymes. Often this is done with chemical crosslinks (BDDE). Manufacturers of those hyaluron injectable gels use different stabilizing or crosslink technologies and different number of crosslinks, which impacts the gels consistency and longevity. They aren´t completely resistant to hyaluronidase, as it can be used to dissolve injected hyaluron. As hyaluron is anyway depleted and replenished every day, this dissolving procedure hardly affects skin´s own hyaluronic acid content. This is a common misconception.

In skin care however, the use of crosslinked hyaluron (hence lasting for months or longer) does not make a lot of sense as we usually cleanse our skin twice daily and thus wash it away. It is too large to penetrate. There are some benefits for crosslinked hyaluron, but it does not impact the longevity of skin´s own hyaluronic acid content. One ingredient derived from the roots of Chinese Licorice plant called Enoxolone (also known as Glycyrrhetinic acid) however, has proven to decrease the HYAL1 activity by 54% (in vitro) (5.6). This is a novel and safe topical way to protect skin´s own hyaluronic acid content from fast degradation and elimination.
​
However, as mentioned before free radicals increase HYAL1 activity and as we age our skin becomes less resilient against accumulated oxidative stress. Therefore, the most optimal approach to inhibit increasing break down of hyaluronic acid is to combine HYAL1 inhibition with powerful anti-oxidants. In the illustration, which I created professionally, it is Saponin. Saponin is next to a powerful anti-oxidant, also a potent bio-stimulator of the fibroblast for hyaluron (+256%) and collagen (+49%) (6). Furthermore, Enoxolone stimulates melanin production, supports the skin's own repair mechanism against UV-induced DNA damage and inhibits enzymatic elastin degradation. What a power-couple to have in dermo-cosmetic products to manage the biological degenerative process of ageing skin. 
 
Take care

1. HA: a key molecule in skin aging E. Papakonstantinou
2. Dermatoendocrinol. 2012 Jul 1; 4(3): 253–258. doi: 10.4161/derm.21923 Hyaluronic acid: A key molecule in skin aging Eleni Papakonstantinou, 1 Michael Roth, 2 and George Karakiulakis 1 
3. BMC Complementary and Alternative Medicine December 2013, 13:304| In vitro determination of the anti-aging potential of four southern African medicinal plants Authors Gugulethu NdlovuEmail, Gerda Fouche, Malefa Tselanyane, Werner Cordier, Vanessa Steenkamp
4. Bioorg Chem. 2018 Apr;77:159-167. doi: 10.1016/j.bioorg.2017.12.030. Epub 2018 Jan 4. In-vitro evaluation of antioxidant, anti-elastase, anti-collagenase, anti-hyaluronidase activities of safranal and determination of its sun protection factor in skin photoaging. Madan K1, Nanda S2.
5. EADV Poster 2021 A holistic hyaluron-centric anti-aging concept to improve static and dynamic wrinkles Geloven van A, Harbig S, Stuhr A, Dunckel J, Kuhn A, Dippe R, Warnke K, Beiersdorf AG, Hamburg, Germany 
6. EADV Poster 2021 Multifaceted novel approach to increase skin’s own epidermal & dermal hyaluron content Bussmann T, Warnke K, Krüger A, Möller N, Harbig S, Stuhr A, Dunckel J, Geloven van A, Weise J, Beiersdorf AG, Hamburg, Germany
7. Hong et al. Glycyrrhetinic Acid: A Novel Modulator of Human Skin Pigmentation and DNA-Repair September 2009Journal of Investigative Dermatology Conference: 39th Annual European-Society-for-Dermatological-Research Volume: 129

Polynucleotides (PNs) are a type of biomolecule that have recently gained traction in the field of skin care and aesthetic treatments. PNs are composed of multiple nucleotides, which are the building blocks of DNA and RNA. These biomolecules have shown promise in improving the appearance and health of the skin through their ability to stimulate cell growth (activate growth factors), tissue regeneration incl. collagen production, wound healing, fibroblast proliferation and have anti-inflammatory properties.

Polynucleotides (PN) are linear polymers composed of many nucleotide units and they play a key role in the storage and transmission of genetic information. There are two types of polynucleotides (aka nucleic acid) found in nature: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). As mentioned, PN are composed of nucleotides, which consist of 3 parts: a nitrogenous base, a phosphate group. and a five-carbon sugar (2'-deoxyribose in DNA or ribose in RNA). The five base nucleotides are adenine, guanine, cytosine, thymine, and uracil. A DNA molecule consists of two long polynucleotide chains composed of four types of nucleotide subunits: adenine, thymine, guanine, and cytosine, while RNA uses adenine, guanine, cytosine and uracil. 

REGENERATIVE AESTHETICS

Regenerative aesthetics is an emerging branch of regenerative medicine with therapies or products aimed at recapturing youthful structure and function using the body's own systems. Examples of such treatments are platelet-rich plasma (PRP), the use of exosomes or polynucleotides.
Dr. Kate Goldie explained soft tissue regeneration fundamentals as following: 
1. Regeneration of tissue architecture (structure): tissue composition - component abundance, ratio's, position, density and biomechanics/integrity
2. Regeneration of tissue function: signaling, cell function, cellular components (incl. senescence), gene expression and molecular interaction.
The 3 treatment pillars of regenerative aesthetics are: cells, biocues and bio-stimulatory scaffolds. Key superficial soft quiescent cells are the fibroblasts and adipose derived stem cells. One of the big advantages of regenerative aesthetics is by using the body's own system, the results are natural and focused on "skin health" (function) and "skin quality" (appearance).

POLYNUCLEOTIDES IN REGENERATIVE AESTHETICS

Polynucleotides are most often natural, highly purified DNA molecules extracted for example from trout gonads and activate specialised cells called myofibroblasts and adipocytes. PN containing devices act as short time temporary fillers thanks to the viscoelasticity of the long DNA fragments and improve skin well‐being (cell growth) and steady self‐repair (tissue regeneration). Studies support their dermal reactivating properties or their efficacy as “bioreactivating primers” of skin. The final outcome is more natural and in‐depth tissue regeneration and a healthier look of the skin: a more radiant complexion, even skin tone, reduced appearance of fine lines, wrinkles and sagging, faster wound healing, improved pore size and skin thickness, elasticity and hydration. Furthermore, PNs are generally well-tolerated by the skin and have a low risk of adverse effects. Their effectiveness may vary depending on the individual's skin type, age, and overall health. The long-term effects of PNs on the skin are not yet fully understood, and more research is needed to determine their safety and efficacy. There are various brands available which use polynucleotides in their (meso-) injection gels. For example Mastelli Srl, Italy NEWEST® (Polynucleotide and Hyaluronic Acid) for bio-revitalization, BR Pharm HP Cell Vitaran Skin Healers, NUCLEADYN® or Nucleofill®.

One brand of (synthetic) polynucleotide-based skin care products is Yuva by Dr. Devgan Scientific Beauty. The Yuva line includes a range of products formulated with PNs, such as the Yuva Serum and the Yuva Enhancer. These products are marketed as being able to provide hydrating, anti-aging, and skin-rejuvenating benefits.

THE FUTURE OF POLYNUCLEOTIDES

While polynucleotides have many benefits, they also have some drawbacks. One of the primary limitations is their instability in certain environments. This instability can make it difficult to synthesize and manipulate polynucleotides in the lab. Moreover their are limitations, risks and ethical concerns harvesting or using (human identical) PN's, and long-term safety and efficacy data is not conclusive. However, PNs are a promising area of research in the field of skin care and aesthetic treatments and regeneration. We can expect to see further advancements in the development of PNs-based products and treatments. PNs are already used in combination with other biomolecules, such as hyaluronic acid, growth factors and anti-oxidants and used in combination with other treatments. For a personal recommendation on which aesthetic treatment is most suitable to aesthetically regenerate your skin, please consult an experienced board certified dermatologist, plastic surgeon or cosmetic doctor. 

Take care.

Glycation is one of the basic root causes of endogeneous (intrinsic) skin ageing and a very challenging one or almost impossible one to reverse. Glycation is an ageing reaction which begins in early life, developing clinical symptoms at around 30, and progressively accumulates in tissues and skin due to the glycated collagens that are difficult to be decomposed. Glycation occurs naturally in the body when sugars react with proteins and lipids to form advanced glycation end products (AGEs). AGEs can be exogenously ingested (through food consumption), inhaled via tobacco or endogenously produced and formed both intracellularly and extracellularly. AGE modifications lead to dermal stiffening, diminished contractile capacity of dermal fibroblasts, lack of elasticity in the connective tissues, contribute to hyperpigmentation and a yellowish skin appearance. The formation of AGEs is amplified through exogenous factors, e.g., ultraviolet radiation. 

AGEs cause changes in the skin through 3 processes:

1. AGEs interact with specific cell receptors, altering the levels of soluble signaling molecules, such as cytokines, hormones, and free radicals.
2. In the process of non-enzymatic glycation reaction, a large number of reactive oxygen radicals are released, creating a state of oxidative stress, leading to a significantly reduced level of glutathione, Vitamin C, and Vitamin E in the body. This causes synthetic disorders of collagen in skin tissues. 
3. AGEs alter the physical and biological properties of the original extracellular matrix proteins, such as collagen. 

Many cells have AGEs receptors on the surface, such as macrophages, mesangial cells, fibroblasts, and endothelial cells, through which their function can be affected. They induce oxidative stress and trigger inflammatory pathways by forming crosslinks, altering protein structure, or by binding to AGEs receptors. AGEs cause cellular dysfunction through the modification of intracellular molecules and accumulate in tissues with ageing. This causes the skin and connective tissue to harden and lose their ability to regenerate healthy cells. They cause damage to extracellular proteins like collagen and elastin fibers, which are crucial for maintaining skin structure and firmness. This damage leads to the breakdown of these fibers. AGEs can also affect intracellular proteins like vimentin. AGEs can act as a catalytic site for free radical formation, exacerbate intracellular oxidative stress, and increase ROS production through a variety of mechanisms, reducing glutathione (skin's own anti-oxidant) storage, and activation of protein kinase C, etc., to accelerate the production and accumulation of AGEs. 

One study published in the Journal of Investigative Dermatology found that levels of AGEs were higher in the skin of older individuals compared to younger ones. The study also showed that there was a correlation between the level of AGEs and the severity of skin ageing. This suggests that inhibiting the production or accumulation of AGEs in the skin is a potential target for anti-ageing interventions or skin ageing management.

AGEs are complex and heterogeneous, more than a dozen AGEs have been detected (however not all) in tissues and can be divided into three categories according to their biochemical properties. 
​AGEs are formed through four pathways:

1. the Maillard reaction (non enzymatic reaction between amino groups of proteins and reducing sugars, binding sugars to proteins)
2. sugars auto-oxidation pathway (metal-catalyzed auto-oxidation of glucose or Wolff pathway) 
3. lipid peroxidation pathway (acetyl alcohol pathway)
4. polyols pathway (glucose is converted into fructose via the polyol pathway, which accelerates the production of AGEs)

GLYCATION INHIBITION IS KEY 
AGEs can be crosslinked through side chains to form a substance of very high molecular weight, which is not easily degraded. The consequences from skin glycation are irreversible. This makes prevention or inhibition of the process the best potential strategy to maintain skin health and ageing skin management. One way to do this is by altering the diet to reduce the intake of sugars and carbohydrates, which are known to contribute to glycation. Several studies have found that reducing sugar intake can result in significant improvements in skin health, including reducing wrinkles and improving skin texture. 

AGE inhibitors
Another potential strategy is the use of topical agents that inhibit the formation or accumulation of AGEs in the skin. One study published in the Journal of Cosmetic Science found that a cream containing carnosine, a peptide that inhibits glycation, improved skin elasticity and reduced the appearance of wrinkles in individuals with ageing skin. Skincare containing NAHP or Acetyl Hydroxyproline inhibits the formation of AGEs significantly (in vitro), most likely through a mechanism where NAHP competes with the proteins for the sugar. Finally, NAHP sacrifices itself in place of the proteins and gets (at least partially) glycated. NAHP also prevents loss of cellular contractile forces in a glycated in vitro dermis model and counteracts the diminished cell-matrix interaction that is caused by glyoxal-induced AGE formation.

​Anti-Oxidants
Moreover, I would suggest to combine those ingredients with an ingredient like Licochalcone A. Numerous high ranked publications support that Licochalcone A protects cells from oxidative stress mediated by e.g. UV and HEVIS (blue light) induced reactive oxidative species (ROS). Due to the activation and nuclear translocation of the transcription factor NrF2, the expression of anti-inflammatory, antioxidant and detoxifying enzymes are induced. These enzymes protect the skin cells (like keratinocytes and fibroblasts) from ROS-induced damage, like lipid peroxidation and DNA as well as protein damage. If Licochalcone A is combined with L-Ascorbic Acid, (the most active form of Vitamin C), it supporting skin's own collagen production, provides superior biological cell protection amongst other relevant benefits. My absolute favourite product is Eucerin Hyaluron-Filler Vitamin C Booster which I use daily as a serum in my morning routine.

GLYCATION AND SKIN HEALTH

Acne
In addition to its role in ageing, glycation in the skin has also been linked to a range of skin health problems. One study published in the Journal of Cosmetic Dermatology found that the level of AGEs in the skin was significantly higher in individuals with acne than in those without acne. The study also showed that treating acne with a topical antibiotic significantly reduced the levels of AGEs in the skin.

Atopic Dermatitis
Another study published in the Journal of Investigative Dermatology found that individuals with atopic dermatitis had higher levels of AGEs in their skin than healthy individuals. This suggests that glycation may play a role in the development of inflammatory skin conditions.

Diabetes + Woundhealing
The correlation between high sugar levels and skin ageing can be seen in diabetic patients, where one-third of this population has skin complications. A prominent feature of ageing human skin is the fragmentation of collagen fibers, which severely damages the structural integrity and mechanical properties of the skin. Elevated levels of MMP-1 and MMP-2 and higher crosslinked collagen in the dermis of diabetic skin lead to the accumulation of fragmented and crosslinked collagen, thereby impairing the structural integrity and mechanical properties of dermal collagen in diabetes. Collagen crosslinking makes it impossible for them to easily repair, resulting in reduced skin elasticity and wrinkles. Keratinocytes and fibroblasts are the main cells involved in wound healing, but due to the high glucose (HG) microenvironment in diabetics, the functional state of these cells is impaired, thereby accelerating cellular senescence (programmed cell death).

Conclusion
We can't completely stop the glycation process, therefore it's important that we inhibit it from a young age onwards, hence monitor the sugar intake of our children, use daily SPF and invest in good dermo-cosmetic products containing ingredients like NAHP and powerful anti-oxidants like L-Ascorbid Acid (Vitamin C is needed for the production of collagen) and Licochalcone A (also anti-inflammatory). Preventing signs of ageing, specifically caused by glycation is most effective. If your skin shows (advanced) signs of ageing, you can get visible improvement using skin component (hyaluron, collagen and elastin) bio-stimulating ingredients like Retinol, Bakuchiol, Arctiin, Creatine or Glycine Saponin. Consult your dermatologist if you wish to improve your skin's appearance or skin health issues.

Take care

Special thanks: Ph.D. dr Julia M. Weise Manager Biological Testing & Dorothea Schweiger Lab Manager Facial Skin Biology Beiersdorf HQ Hamburg

Skin boosters using micro-injections with predominantly non-crosslinked hyaluron filler gels like Restylane® Vital, Juvéderm® VOLITE or Belotero® Revive are gaining popularity for very good reasons. Unlike traditional dermal fillers, they are not injected beneath the skin to volumise or shape the face. Instead, they are very fine dermal easily integrated "fillers" that are injected into the skin to hydrate, improve skin quality and give very natural results. They are also gently bio-stimulating, meaning they "stretch" the fibroblasts in the injected area and as a result this cell is producing more collagen. An effective bio-remodeling skin booster using 2 times 5 injection points (bio-aesthetic points - BAP) for a full-face treatment is Profhilo®. However, the recent K-beauty treatment via topical application or micro-injections with bio-remodeling exosomes is gaining popularity.

Exosomes are nano-sized cargos with a lipid bilayer structure carrying diverse biomolecules including lipids, proteins, and nucleic acids. These small extra cellular vesicles are secreted by most types of cells (skin relevant are the keratinocytes and fibroblasts) to communicate with each other. Exosomes circulate through bodily fluids and can transfer information. ​They can be either good or bad, however taken from a healthy young cell they will be sending the best messages. Studies have shown the efficacy of exosomes in skin ageing. They can facilitate skin remodeling (increasing collagen and decreasing senescent cells) leading to skin rejuvenation.

Cells sleep because they don't get enough bio-stimulation: messages. Better messages is better skin architecture. This is why exosomes are so important. At the World Stem Cell Summit it used to be 90% about stem cells (they only life 28 days) and 10% about exosomes, now it is 50/50. The reason is called heterochronic parabiosis. 1. One of the most robust methods of improving the function of ageing tissues is that of heterochronic parabiosis,. The effect was shown in a study with a surgical procedure whereby a young and old mouse are joined together so the share one circulatory system. 2 This study according to dr Kate Goldie AMWC 2023 Monaco is proof that it is not the cells, but the messages they give that is transforming lots of different tissues, which has the ability to profoundly regenerate tissues. That is why people are so interested in exosomes. Exosomes taken from a very young cell give potentially the best messages as they "send the message" of youth. EV (Extra-cellular Vesicle) is the actual correct term as messages come as micro-vesicles and exosomes and form 2 different messages from the cell. 3 We start to understand active ingredients. In exosomes one of the most important ingredients is RNA and is part of the future of regenerative aesthetics. Messenger RNAs up-regulate and Micro-RNAs down-regulate. They physically go into the cell and change how the cells works. So we have to be cautious. In this study "The therapeutic and commercial landscape of stem cell vesicles in regenerative dermatology" dr Kate Goldie et al. assessed all available exosomes in the (UK) market.

Most exosomes used in-office are extracted from human stem cells and frozen to keep them as stable. Unlike actual stem cells, exosomes don't have a nucleus and therefore they are safe to use. Exosome therapy is the application of topical exosomes after in-office treatments which disrupt the skin barrier, like laser resurfacing, chemical peelings or microneedling. Exosomes are also used in micro-injections as a stand-alone skin boosting treatment and in a few skin care products. Be aware that as usual, not all products are alike. The way exosomes are sourced (origin), size, their content (can be growth factors) and function determine largely their efficacy and the price of the product. 

One of the challenges is that we do not really know what is in the exosomes. They are like small packages with a lot of messengers. The use of exosomes looks promising for several indications: regenerative aesthetic medicine, healing, scar treatment, burns and atopic dermatitis, however their safety is not yet fully established and no official registration for their use granted.



​Take care

1. Cell Cycle. 2012 Jun 15; 11(12): 2260–2267. Heterochronic parabiosis for the study of the effects of aging on stem cells and their niches
Irina M. Conboy 
2. Heterochronic parabiosis reprograms the mouse brain transcriptome by shifting aging signatures in multiple cell types Methodios Ximerakis
3. J Cell Biol. 2013 Feb 18; 200(4): 373–383. Extracellular vesicles: Exosomes, microvesicles, and friends Graça Raposo et al

Skin flooding is the latest TikTok trend to counteract dry or dehydrated skin. It is basically layering hydrating mists, serums or creams to boost hydration in the skin. The idea is to start with a humectant-rich, lightweight products first and then add a thicker emollient to seal in the moisture on the skin. This is a trend which is suitable for all genders at all ages if products are chosen wisely.

DRY OR DEHYDRATED SKIN
There is a difference between dry and dehydrated skin. Dehydrated skin is water-lacking skin, considered a skin condition and can be temporary, while dry skin is lipid-lacking skin and seen as a skin-type. All skin types (yes including oily skin) can be dehydrated. Picture yourself in an environment like airplane without any humidity. Our skin will react to this "dehydration condition" by either (over)production of oils and lipids to "protect" itself fro drying out or get very dehydrated. When the skin is producing a fierce amount of oils and lipids as compensation, you do not have lipid-lacking or dry skin, however your skin might be dehydrated. Lipid-lacking or dry skin has less ability to produce those oils or lipids and often has an impaired skin barrier. Lipids are the "mortar" between the bricks and when they are lacking, more water will evaporate from the skin and thus it loses hydration.

FLOODING
Therefore "flooding" without "suffocating" the skin, can be a good approach for dehydrated skin and all skin types at all ages. If you want to start your flooding regimen on damp skin, you start immediately after cleansing and toning or use a light mist containing hyaluronic acid and glycerin. Both ingredients are powerful humectants and attract and bind water to the skin surface. Afterwards you might want to first apply a hyaluronic acid containing serum and then a cream to "seal the deal". The difference between flooding and slugging is that flooding is focusing on maximising skin hydration or moisture, while slugging is focusing on prevention of trans-epidermal water loss by (semi)occlusion. Read more about slugging.

HYALURONIC ACID 
Be aware not all hyaluronans are the same. There are different sizes. A macro-hyaluron (about 2000 kDa or larger) will lay on the surface of the skin and bind water there where the skin is losing the most water. A biologicaly active size hyaluron is the 52 kDa micro-hyaluron. This particular size molecule has proven to penetrate into the metabolic active layer of the epidermis, where is actually stimulates the keratinocytes (a certain skin cell) to produce +209% more hyaluron. This can be enough when you are young as the decline of hyaluron in the skin starts first in the epidermis.

Be aware it is NOT recommended to use a hyalruon size below 30 kDa in skin care. Hyaluronic acid has the ability to bind and attract water up to 10.000 times is molecular weight, are great to plump up the skin, however the smaller sizes have a different function and can actually harm the skin by for example causing inflammation. 

LINES AND WRINKLES
If you get a bit older, also the dermis will lose it's most important filling substance (hyaluron). There is another skin cell type which can be stimulated to produce more called the fibroblast. This cell is a key cell in the junction of the epidermis and dermis and the dermis, so deeper layer. The powerful anti-oxidant and bio-active Glycine Saponin or abbreviated Saponin can bio-stimulate this cell to produce +256% more skin's own hyaluron and +49% more collagen. Moreover, there are products on the market which contain all of the above PLUS Enoxolone. Enoxolone has the ability to inhibit the activity of an enzyme called HYAL1 >50%. HYAL1 is one of 6 different hyaluronidase enzymes which degrate skin's own hyaluron, hence eliminate it from our skin. These enzymes get more active in sun-exposed or mature skin and are partially responsible why our skin will lose hyaluron as we age. Together with the anti-oxidant Saponin, Enoxolone can slow down the elimination of skin's own hyaluron via 2 complimentary pathways: physical and enzymatic degradation. With other words, products containing 2 different sizes of hyaluron, Glycine Saponin and Enoxolone will fill, stimulate and defend skin's own hyaluron in both the epidermis (top layer) and the dermis (middle layer) of the skin. Great for dehydrated and early or visible signs of ageing, like fine lines and (even deepest) wrinkles.

DAY AND NIGHT
For daytime I would highly recommend a cream with protective SPF and for nighttime a product containing regenerative and barrier repairing Dexpanthenol or Pro-Vitamin B5. Anti-oxidants are good in every day and night time routine. If you want to use a refreshing hydrating mist, there is only one product with hyaluronic acid I recommend and it is Eucerin Hyaluron-Filler Mist Spray. The reason for this is that it has a skin friendly pH unlike (thermal) water. Water has a pH of 7-8 which is like a slight "insult" to the skin's healthy pH every time you spray. With the Hyaluron-Filler Mist Spray, you rebalance the skin's healthy pH level and use it as much as you like. pH to me is the foundation of good skin health. I have written a few pH related blog-posts and if you are interested simply click on the "read more" button below.

Take care

We all learned that sleeping in make-up is the ultimate skincare sin. What is bad about it is when you go 24 hours without washing your face and end up going to bed leaving your day-time make-up on. Over the course of the day, our skin accumulates pollutants, dirt and dead skin-cells.

If dirt and pollutants are left on the skin, they may cause micro-inflammation and contribute to premature ageing skin via a process called inflamm-aging and free-radical damage which is a major contributor to skin-ageing. The combination of both micro-inflammation and free-radical damage is called ox-inflammation. We should aim to reduce or preferably avoid it. Pollution, dirt and sebum (oils) can impact the skin's healthy pH balance and thus lead to a weakening of the skin barrier function, more sensitive skin, dehydration, slowed down skin-cell renewal process and thus ageing. Not removing dead skin cells together with dirt increases the risk of clogged pores. 

Make-up itself usually doesn’t contain harming ingredients. Coloured micro-pigments actually provide additional sun-protection. Make-up or foundation itself is thus not the problem, however the fact that we don’t cleanse our skin after a busy day and/or evening is what could make us age faster. Not doing your PM cleanse and care routine is anyway a missed opportunity to support your skin’s night-time recovery with beneficial active ingredients.

If you go out in the evening, take the opportunity to cleanse before getting ready and get rid of debris which was accumulated during day-time.

Don’t worry about falling asleep in your make-up once or twice. Just don’t make it a habit. I would always aim to remove eye make-up. Sleeping in full eye make-up (mascara, liner, eyeshadow) increases the risk of an eye-inflammation, redness and corneal abrasions. Waking up with “panda-eyes” filled with black rheum or goop isn’t pretty either.

Take care

Vitamin C is a "must have" skin care ingredient our skin needs at any age.
 
One of the best researched skin care ingredients and proven to be very beneficial for skin is Vitamin C. Our skin uses Vitamin C as an anti-oxidant and the dermal fibroblasts need Vitamin C for the production of collagen. Two very good reasons to add this ingredients into your daily skincare routine whether you are twenty or eighty. Moreover, our skin depends on us for the needed supply, as our skin is not able to produce Vitamin C itself.
 
We can either include enough Vitamin C in our diet or apply Vitamin C topically there where we need it the most. Usually this is the skin which is exposed to (sunlight) as this increases damaging free radical activity in our skin. An active form of vitamin C can reduce the free radical activity, which we call anti-oxidative effect. 
 
There are 4 things to consider when buying a skincare product containing Vitamin C:

1. Vitamin C needs to be used in an active form. Fresh reconstituted (mixed) L-Ascorbic Acid is the most active form of Vitamin C. A stabilized form of Vitamin C is not active anymore and therewith not as effective or not effective at all.
2. The formula has to have a low or very low pH value in order for the vitamin C to penetrate well into the skin.
3. The percentage of vitamin C needs to be above 8 and not over 20 to be optimal. For a good balance between great efficacy and tolerability, 10% fresh L-Ascorbic Acid is just right. Higher might not add much efficacy, but could create tolerability issues, especially for more sensitive skin.
4. The packaging and application form should protect the formula from light & air as much as possible. A dropper for example will expose the formula to air with every use.

 
Day or night?
Some recommend to use Vitamin C during the night, as the active form of Vitamin C will oxidize in daylight. Hence, your skin can benefit from the Vitamin C longer during the night. I would recommend Vitamin C to be used during daytime (thus added to your morning routine), as we need protection from damaging free radicals the most during daytime and the oxidization of Vitamin C is actually a sign that the ingredient is doing it’s job! It’s even better to add Vitamin C both to your day & night time skincare routine.
 
Is L-Ascorbid Acid enough?
Vitamin C is counteracting free radicals from UV light. However, UV is not the only damaging light form as there is also High Energy Visible Light or abbreviated HEVIS. This penetrates even deeper into the skin where also the dermal fibroblasts reside. The dermal fibroblasts are our collagen and hyaluronic acid producing cells and a key target in an effective anti-ageing skincare strategy. Lichochalcone A (Licorice-root extract) has proven to be the most potent anti-oxidant to protect the dermal fibroblasts and neutralize free radicals from HEVIS. Moreover, Lichocalcone A increases Glutathione, which is a skin’s own anti-oxidant. Licorice-root extract is an anti-ageing hero.

Summary
The combination of Vitamin C and Lichocalcone A will protect our skin and dermal fibroblasts from free radical damage by UV and HEVIS and will provide superior biological cell protection in comparison to Vitamin C only. For me this is a good reason to use a product containing both ingredients as a first step after my cleansing routine in the morning. If you have sensitive eyes, I recommend to use an eye care prior, which will form a barrier to help to prevent the low pH Vitamin C product to migrate into the eye area. Afterwards you can use the other products of your skincare routine. I would like to put emphasis on using a SPF of 30 or higher during the day. This will not only help to protect your skin, but also support he anti-oxidative benefits and make them last longer.
 
Hope this was helpful.
Take care!

After about spending some time in bathtub or in the pool, we can notice that our skin on particularly finger tops and toes start to wrinkle up. This wrinkling effect is believed to have a function.

When wet, things tend to be more slippery and our sophisticated skin is designed to counteract this by wrinkling up in a pattern optimised to provide a drainage network that improves grip, much like the tires on a car according to a study. Link to original publication. However, other studies would contradict that there would be a functional benefit for so called aquatic wrinkles.

The osmosis theory
Water molecules moving trough a semipermeable membrane from a low concentration area to a high concentration area is a process called osmosis. The shrinking and expanding effects of osmosis takes place simultaneously outer layer of the skin, causing wrinkles.

The skin's outermost layer is also known as stratum corner could be responsible for this wrinkly reaction, The top layer of our skin consists of dead corneocytes. The longer these cells are attached to the skin, the bigger they are. The size of the corneocytes we actually use to objectively measure the skin's renewal and desquamation (shedding of cells) process. These dead (keratin containing) skin cells may absorb water and swell. The lower layer with living cells doesn't swell up. As top layer (which is increased in size) is still attached to the layer beneath, a wrinkly pattern is formed. The layer of dead skin cells is thicker at the palms of our hands and soles of our feet, the wrinkling effect is more evident. This response occurs more quickly in freshwater than seawater. Moreover, when we are exposed to water for a longer time, the water-repelling film on top of the outer layer of the skin may get impaired.

The sympathetic nervous system / microcirculation theory
It's known that there is a relationship between the wrinkling-effect and blood vessels constricting (narrowing) below the skin. When hands and feet are soaked in water, the nerve fibres in the skin shrink and the body temperature regulators loses volume. Therewith the top layer of the skin is pulled downward and the wrinkling pattern is formed. It is proven that wrinkling-effect response is impaired, if the nerves and/or blood vessels are damaged. Therewith the wrinkling effect can even be used to determine proper functioning of the sympathetic nervous system and/or skin's microcirculation. There is evidence that the wrinkling effect is impaired in patients suffering from diabetes: link to article. 

Regardless the cause, aquatic wrinkles disappear fast and the skin returns to normal once the water has evaporated.
​
Take care.