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Nanotechnology in Skin Care

The year was 2000. They told us that nanotechnology is great and that it is the “decade of nanotechnology”. Then they tried to sell us stuff by using the word “nano”.

Ten years later, Robin Cook wrote a medical thriller titled “Nano”.

Soon after, some people began to say that nanotechnology is bad. They ask for money to fund “non-profits” to put pressure on Congress so that everything nano can be banned.

What is nano? You probably learned about this term in high school, when studying the metric system. The nanometer is one thousandth of a micrometer, which is one thousandth of a millimeter, etc.

How small is a nanometer?  Below is a (logarithmic) scale showing where the atom is compared to a giant sequoia.



Where will you encounter the terms nanotechnology or nanoparticles in skin care? In marketing. These are used as scientific-sounding terms to convey extra penetration of ingredients into the skin. In these cases, just ignore the words completely. It was introduced into the advertising world by marketing departments. You need to check the ingredient list, or ask about the ingredients in the SAS forum.


Remember Myth #1? “The skin is impermeable”? It is NOT.

The skin is not an impenetrable film of plastic, it is a biological system with plenty of entry points, especially in aging skin.

If the skin were impermeable, you clearly would need that delivery system consisting of those nanoparticles designed by that famous scientist in Switzerland. Unfortunately, that famous scientist in Switzerland does not exist, or never published anything in a reputable scientific journal. More important, he is lying about skin properties: the skin is not impermeable and you don’t need any delivery system to get an active ingredient into your skin. Whatever you apply to the skin will be absorbed, for better or for worse.

The outermost layer of the skin, the stratum corneum, limits water loss from the body to the environment. It allows human organisms that depend totally on water, to walk around in the Arizona desert and still be able to live. The stratum corneum also limits penetration of water and chemicals into the skin, slowing absorption of nutrients (and noxious chemicals) applied topically. “Limits” does not mean that this layer is impermeable, as shown by trans-epidermal water loss. Trans-epidermal water loss can be measured easily with a laboratory instrument, and it increases with age and skin damage. In photo-aged skin the absorption of external nutrients will be higher than in young skin, just like trans-epidermal water loss is higher.

The absorption of water-soluble nutrients through the skin will increase with skin humidity, so it is a good idea to take advantage of the skin’s higher permeability after a shower or bath. Even a low uptake of nutrients, such as amino acids, applied topically should substantially improve the health of skin deprived of nutrients by the decrease of blood supply to the dermis that occurs to all of us when we age. This is valid for all useful actives applied topically. You don’t need to absorb 100% of them, so forget about “delivery systems” because you don’t need them.

The Real Nanoparticles

Effective products that contained physical sunscreens used to be white and were not particularly flattering. At the end of the last century, new technology devised ways to make the particles “invisible” by decreasing their size.This is not a problem with zinc oxide, because zinc is an element required by the human body and the body is great at maintaining the concentration of zinc at an optimum value. This way we get a nice sunscreen, like the one we sell at Skin Actives, and it does not even show!So, what is the problem? What matters is the chemical composition. Humans do not need titanium and are not very good at dealing with it. So, whose idea was it to make nanoparticles of titanium oxide and apply them to the skin? And whose idea was it to make nanoparticles containing silver and copper? Silver and copper are bad ideas at any particle size. True, copper is required by the body, but at such low concentrations that it is silly to apply it to the skin unless we are discussing the very particular case of healing wounds.Conversely, nanoparticles of a particular chemical composition may be useful to kill bacteria and cancer cells if they are directed properly. As with everything else, these particles may be dangerous to humans and the risk/benefit will have to be taken into account.


The Latest Silliness: Nanoparticles as Endocrine Disruptors

The inference that nanoparticles are endocrine disruptors came from badly done experiments. This provided fodder for a grant application for those obscure non-profits that try scaring people with fake data. It is possible to disrupt any living system if you add enough of anything, the “anything” does not have to be in the form of nanoparticles.


In Short: The Facts

First, whatever is applied to the skin will penetrate. The skin is not plastic, it is a permeable membrane.Second, zinc oxide is safe. Particle size is unlikely to change that. We need it, we use it, we manage it pretty well. This is the physical sunscreen present in Skin Actives’ sunscreen. Apply away and it will protect you from skin damage, skin aging, and skin cancer.As for the other metal nanoparticles, that is not necessarily the case. Titanium is not needed by the human body. Titanium oxide is insoluble and zinc oxide should be used in sunscreens instead.Copper, as we all know by now, is required by the body but we get enough from the environment. Adding more copper to the skin is bad unless you are looking to heal a wound.Silver is not necessary, in any size, shape or form, unless you want to wear it as earrings.


-Dr. Hannah Sivak