All About Nanotechnology And Skincare

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Many skincare products, including ones you may use, contain nanotechnology, or nanotech. But there seems to be a divide in our perception of nanotech. On one side, it is easy to find opinion pieces, blog posts, and articles that treat nanotech as a scary four-letter-word that should be avoided at all costs. However, from a research perspective, nanotechnology is all the rage and if you believe the news, it is set to revolutionise our lives from the sciences and engineering, to pharmaceuticals and medicine.

So, as a skincare enthusiast, where does this leave me? Should I avoid nanotech or embrace it? Having asked myself this, I delved into the scientific literature to try and understand what the deal with nanotech really is (hint: there’s good news and bad news).

What is Nanotechnology?

In its most basic definition, nanotech is the manipulation of matter at a “nano”-size, or between 1 and 999 nanometres (nm) across at least one of its dimensions, although some definitions require the size to be from 1–100 nm. For context, one nanometre is one billionth of a meter (1×10-9). If you are as mind-boggled as I am by the smallness of this, check out this fun graphic to put this into perspective.

When I think of nanotechnology, I usually picture nanoparticles, nano-sized balls of a compound, often metals like silver or titanium, but also silicon and solid fats. But while nanoparticles are a major form of nanotech found in skincare, there are others, including nano-emulsions and even carbon-based structures like fullerenes. As the name suggests, nano-emulsions are mixtures of two non-mixable liquids, such as oil and water, where the emulsified droplets are nano-sized. Fullerenes are especially interesting, they are spherical molecules made of carbon that look something like a skeletal soccer ball.

Why are they in my skincare products?

Skincare products are formulated with nanotech for several reasons, to improve their appearance, to add or increase the benefits of active ingredients, and even as antibacterial agents2.

One common use of nanoparticles is in physical sunscreens, where it is used to reduce the white cast caused by titanium dioxide and zinc oxide. Nanoparticles of titanium dioxide and zinc oxide retain their ability as physical sunscreens, but the re-formulation renders them more transparent, making the product more visually appealing2.

Nano-emulsions are also appealing for their transparency. If you picture most emulsions, such as milk or mayonnaise, they tend to be opaque white; however, due to the small size of the emulsified droplets, light is unable to interact in the same way and passes through, rendering the mixture much more clear3.

Nano-emulsions are also appealing for their transparency. If you picture most emulsions, such as milk or mayonnaise, they tend to be opaque white; however, due to the small size of the emulsified droplets, light is unable to interact in the same way and passes through, rendering the mixture much more clear3.

The other major use is to increase the effectiveness of the active ingredients2. As our bodies’ front-line defence against the outside world, our skin is a very effective barrier. Part of this is due to the layered nature of skin, with dead cells on top forming the stratum corneum and living cells underneath. Because of this, skincare products may just sit at the surface of the skin.

In some cases, like physical sunscreen, this is preferable. But for active ingredients in skincare products to be effective, they must be able to reach the living cells. This is especially true for many anti-aging products that otherwise would not otherwise be absorbed into the skin. By formulating these active ingredients as nanoparticles, they can take advantage of different routes to absorb into the skin, allowing them to reach their target and exert their beneficial effects2.

In the case of fullerenes, the carbon they are made of is not especially interesting on its own, but due to the unique shape, fullerenes act as powerful antioxidants. They attract oxidative molecules like a sponge and prevent them from causing damage, which can benefit skin4. For example, they can decrease inflammation, have been shown to improve acne.

Finally, nanoparticles and nano-emulsions can be formulated as solid fats, oils, and carriers of fat-soluble active ingredients. This can improve the efficacy of these active ingredients. These formulations  can also reduce greasiness and heaviness of creams that contain fats and oils, which are typically unwanted in skincare products2.

Many nanoparticles are strongly antimicrobial and are used to prevent contamination and infections. One of the main forms that is used for this property is silver nanoparticles. This property can be used in several ways that benefits skincare products. Most obviously, they can be added to make antibacterial soaps. As well, they can be applied to packaging surfaces to extend product shelf life without adding extra preservatives to the product itself2

But what about

While I was unable to find evidence of nano-emulsion toxicity, nanoparticle toxicity is well documented. In the same way that their small size allows them to travel more effectively to the dermal layer of the skin, this also allows them to more easily enter into cells, where they can cause oxidative stress, which can damage cells and even cause cell death1. Furthermore, once past the skin, nanoparticles can potentially distribute throughout the body. Depending on their formulation, they can accumulate in specific tissues and organs, potentially causing damage.

Unfortunately, the subject is too complex to issue a blanket statement that all nanoparticles are toxic. Toxicity of nanoparticles is influenced by their chemical composition, size, shape, special coatings they may have, and even the formula that they are immersed in2. Using sunscreen as an example, nano-titanium dioxide and nano-zinc oxide are unable to be absorbed substantially in the skin. Unable to reach living cells, there is little concern of toxic effects. However, a recent European Union report suggested that sprayable forms of sunscreen containing nano-titanium dioxide should be avoided to prevent effects on lungs and that some forms of uncoated nano-titanium dioxide are also not recommended due to potential reactivity6.

As another example, fullerene toxicity has been shown to differ vastly based on slight changes in their specific shape and size, so while one formulation may be safe, this cannot be assumed for all fullerenes.

This leads me to my final point and my personal biggest concern. For many nano-formulations in skincare, there simply is not enough scientific research available and even less information for the consumer to conclusively state its safety. Based on what is known on nanotech, it is difficult to make overarching conclusions on safety, since slight variations in formulations can alter toxicity. Because of this, there should be extensive research conducted to determine if products are safe to use.

Luckily, it seems that governments are beginning to respond to this lack of information. For example, the EU put forward a regulation to require product ingredients to specify nano formulations. And in the USA, the FDA is developing a “Significant New Use Rule” that will help to ensure that nano-materials are appropriately reviewed. In a FAQ, Health Canada has stated that, while they do “help protect and promote health by using existing legislative regulatory frameworks” in use of nano-materials, there are no legislation specific to nano-materials. While this better than nothing, there is clearly a need for our governments catch up to the current state of use.

Take-away message

So, what is my final impression on nanotech in skin care products? I wish I could give you a conclusive answer, but we need more research to determine when the benefits outweigh any costs, and vice versa. Nanotechnology has a great potential to revolutionise skincare and in some cases, such as sunscreens, there is strong evidence supporting benefits. Conversely, toxicity can vary hugely between different types of nanotech and even different formulations and to create safe, effective consumer products, toxic forms must be carefully defined so that they are avoided. Finally, to help support research and inform consumers, more stringent guidelines for consumer products should be created.

Personally, I am not going to outright shun products that I suspect contain nanotech, but I do plan on keeping an eye on research and regulation to help me decide if I am comfortable with using a product.

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