As far back as 4000 B.C. with the Egyptians, and later through the Greeks, Romans, Chinese, and Japanese, cosmetics have always been used to alter appearance and have frequently been marketed as luxury goods. Throughout the evolution of cosmetics, research has been aggressively pursued, leading us to the modern era with the introduction of nanotechnology.
Why is nanotechnology important in cosmetics?
Cosmetics can be defined as items used for cleansing or altering the perception of an individual’s physical appearance, leading to an enhanced state of beauty—even though this parameter is extremely subjective.
For these purposes, nanotechnology plays a vital role by intervening in factors such as:
- Ingredient dispersion;
- Optical properties of pigments and dyes;
- Distribution of hydrophobic substances;
- Preservation of photosensitive and chemically unstable ingredients;
- Controlled release of active ingredients;
- Hydration;
- UV protection for the skin.
For instance, a cream may be presented as a soft emulsion that amplifies a fragrance, while the active ingredients are better preserved and absorbed by the skin to ensure prolonged action, anti-aging effects, and optimal skin hydration. Everything is aimed at enhancing the perception of beauty. In products like deodorants, toothpastes, shampoos, lotions, and nail polishes, nanoparticles are used to alter properties such as color, transparency, solubility, and chemical reactivity. Generally, the nanomaterials used can be either organic or inorganic.
Which types of nanoparticles are used in cosmetics?
For each of the two classes mentioned above, different nanoparticles are used based on the specific need. For the organic group, liposomes and natural polymeric nanoparticles are typically used. For the inorganic group, we find fullerenes, micro- and nano-oxides of zinc and titanium, and silica microparticles. In both cases, their size and chemical-physical characteristics make nanomaterials different from other cosmetic ingredients in terms of quality, efficacy, and, above all, safety.
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Liposomes
Liposomes are lipid nanovesicles that protect the active ingredient from degradation and release it in a controlled manner due to their high compatibility with the dermis. Vitamins and antioxidants are the ingredients most commonly encapsulated for use in body sprays, deodorants, lipsticks, anti-aging creams, and hair loss lotions.
Niosomes
Niosomes are nanovesicles capable of encapsulating both hydrophobic and hydrophilic molecules. They have a high dermal penetration capacity, ensuring the stability of the encapsulated principle. Developed by L’Oréal in the 1970s and patented in 1987, they are used in products like the Lancôme line’s creams, shampoos, and skin whiteners.
Lipid Nanostructures
These are an evolution of lipid nanoparticles. They guarantee a higher encapsulation capacity and better preservation of active ingredients combined with very low toxicity. The commercial name for this category is NanoRepair Q10, present in over thirty commercial products.
Nanoemulsions
Nanoemulsions are dispersions of oil in water stabilized by surfactants. They are translucent, have low viscosity, and can solubilize chemically challenging active ingredients very well. Their rapid dermal penetration makes them ideal for moisturizing and anti-aging products.
Dendrimers
Dendrimers are unique nanoparticles with branched “arms” on the surface, allowing for the precise and selective targeting of active ingredients. L’Oréal, Wella, and Dow are just a few of the brands using this technology.
Polymeric Nanoparticles
These utilize polymers that self-assemble around a core. They are highly customizable and suitable for both hydrophilic and hydrophobic molecules. Their stability and flexibility make them suitable for restoring skin elasticity.
Titanium Dioxide and Zinc Oxide
The famous nanoparticles of titanium dioxide and zinc oxide are the primary ingredients in almost all sunscreens. They are insoluble and measure only a few nanometers in size—a characteristic that has brought them to the center of toxicity debates.
Are nanoparticles safe?
Relatively little is still known about the short- and long-term effects of nanoparticles on human health due to a lack of specific longitudinal studies. This is why toxicity is tested by analyzing parameters such as absorption, bioavailability, accumulation, and physiological elimination. Generally, it is assumed that—given the same material—nanoparticles are more toxic than microparticles due to their higher biological reactivity. However, many other factors are involved, such as surface properties, structure, diameter, and the tendency to aggregate.
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It is important to know that certain particles can have undesirable effects on the body:
- Inhalation: Nanoparticles in perfumes, powders, and aerosols can be inhaled and persist in the throat, lungs, and other tissues for up to six months, sometimes entering the bloodstream.
- Ingestion: If ingested via products like face or lip creams, nanoparticles can accumulate in the kidneys, heart, liver, and bones, causing acute toxicity.
- Dermal Penetration: When present in skin products, they can penetrate deep layers, potentially causing allergies, dermatitis, and UV sensitization.
This is a scenario that requires careful attention. However, an alternative to this potentially harmful accumulation is already a reality. At Nanomnia, we choose natural and biocompatible polymers even in the cosmetic field. Our synthesized particles and those within our nanoemulsions are always larger than 100 nm to ensure maximum safety combined with maximum efficacy.