Many skin care 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 1. 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 2. 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 3. Fullerenes are especially interesting, they are spherical molecules made of carbon that look something like a skeletal soccer ball 4.
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 the 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’ frontline 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 skin care products to be effective, they must be able to reach the living cells. This is especially true for many anti-ageing 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 5. 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 products.