Not just a pretty face

Materials World magazine
,
3 Jun 2014
Full section of a tissue construct with cartilage at the top and bone substrate underneath. © Sarindr Bhumiratana/Columbia Engineering

Rachel Lawler looks at the materials science behind the cosmetics industry.

Searching for the perfect colour match across hundreds of beauty products is a perpetual quest for many make-up enthusiasts. Thanks to 3D printing, the search could finally be over. Mink, a 3D printer developed by Harvard researcher Grace Choi, is capable of printing tablets of make-up on demand. Users can select the HEX colour code for their chosen shade and create an eyeshadow, lipstick or foundation in the same hue, at the press of a button. The US$300 printer creates a small cake of makeup that can be pressed into a compact.

But when it comes to cosmetics, colour isn’t the only consideration. In an industry worth more than €67bln in retail sales across Europe, pigments are one of many concerns and 3D printers are not the only technology shaking things up. According to Ernst and Young, in 2013 the value of the industry in Europe reached a high of €180bln, a growth of 4.6% on the previous year, making it well placed to invest in scientific development. And it seems the industry is busy making headway in several areas.

Nanotechnology

The labels of cosmetic products often boast about the use of nanoparticles, but how many of these products actually make use of this technology? The biggest breakthrough has been in sunscreens. Paul Crawford, Head of Regulatory and Environmental Services at The Cosmetic, Toiletry and Perfumery Association (CTPA) says, ‘The most commonly used nanomaterial in cosmetic products is titanium dioxide (TiO2). As a mineral, TiO2 nanoparticles act as tiny mirrors that reflect and scatter UV light. Not only does this form of TiO2 protect the skin from UV extremely well, but it has the added benefit of being easy to apply and appears transparent.’ But there is some debate about the safety of nanoparticles. Dr Mojgan Moddaresi, Technical Manager at Cosmetics Innovations and Technologies Ltd, says, ‘The safety of TiO2 is an ongoing topic. Based on the European Commission’s Scientific Committee on Consumer Safety, application of this material is safe in cosmetic products up to 25% concentration. But there are still doubts about the safety of inhalation through sprayon products containing nanoparticles.’

A collaborative group of Australian scientists from departments including CSIRO and the Royal Melbourne Institute of Technology has recently conducted a study into nanoparticles in sunscreen. Their work concluded that the body’s immune system is able to absorb excess zinc oxide particles that penetrate the skin and discard them before they reach the bloodstream. While this sounds promising, the team warned that the results were only conducted in a laboratory and were, therefore, limited.

Aside from sunscreen, uptake of nanotechnology in cosmetics is slower. Dr Peter Taylor, Principal Lecturer in Pharmaceutics at De Montfort University, says, ‘I’m not aware of much nanotechnology being applied outside of sunscreen, but many products still use the term ‘nano’ in their names.’ The reasons behind this are complex, but the EU’s Cosmetic Regulation currently urges caution on the introduction of these nanoparticles, which could deter cosmetic companies as well as users.

Alternative testing methods

Technology is not the only factor that drives change. Consumer opinion has an effect. After growing pressure, the European Cosmetic Regulation finally came into force in July 2013. Taylor explains, ‘This means that no cosmetic product can be made or marketed within the EU that has been tested on animals, or contains ingredients that have been tested on animals’.

But cosmetic products are still subjected to strict controls. Crawford says, ‘Cosmetic products are controlled by strict safety legislation – the European Cosmetics Regulation EC No 1223/2009. The primary purpose of this is to protect human safety and make the manufacturer or supplier of the cosmetic product responsible for ensuring it is safe and complies with the legislation.’

Since this legislation came into place, work on alternative testing methods has intensified, with some promising results. One example is an international team of researchers working at King’s College London, UK, and the San Francisco Veteran Affairs Medical Centre, USA, that has developed a lab-grown epidermis. The material was grown using human stem cells and could offer a cost-effective alternative to animal testing for cosmetics and drugs. The team also hopes the research could provide potential therapies for skin disorders.

There are currently more than 20 alternative testing methods in development. Crawford adds, ‘Not only do products have to be safe, but any claim made by a product must also be robustly substantiated,’ so research into the properties of skin is also underway

Surgical options
Cosmetic surgery is another area benefiting from increased spending on aesthetic concerns, with the development of new materials to replace damaged or diseased cartilage. Researchers at Columbia Engineering in the USA have recently announced the successful growth of fully functional human cartilage in-vitro from stem cells. The cells were derived from fat tissue and could be used to repair cartilage defects or be used in combination with bone as part of lab-grown grafts for more complex tissue reconstruction. By putting the cells through a condensation stage, as usually seen in the body, before attempting to grow the cartilage, the team created a much better match to human tissue.

Next step?
With progress moving so quickly, it is difficult to predict where the industry will go next. Moddaresi suggests, ‘Recent progress in biological science and stem cell research has provided new hope for personalised cosmetics’. But in the more immediate future, Taylor sees some simpler advances such as the replacement of polyethylene beads in exfoliating scrubs with more environmentally friendly materials.

Plastic beads used in these products can be absorbed or eaten by fish and other sealife, causing them to be passed along the marine food chain. Desert Whale Jojoba Company is offering a natural alternative created from a castor oil and jojoba wax composite. The particles work just as well as polyethylene beads, but prevent the build-up of plastic particles in the ocean.

With investment in R&D remaining high across the sector, the cosmetic industry is worth keeping an eye on – and not just for the latest products.  

What’s in your make-up bag? 

Some of the ingredients commonly used in cosmetic products


Mascara
Paul Crawford, from the CTPA, says, ‘Polymers are used in mascaras to help with the wear of the product. Typically a dual polymer system would be used to help the film resist flaking and smudging throughout the day’. Silicones are used to improve water resistance, and waxes to thicken the lashes.  

Eye shadow
‘The basics of a pressed eye shadow is talc or mica, as they can achieve excellent smoothness,’ says Crawford. Nano particles of TiO2 may be used to provide better coverage, as well as powdered kaolin – a smooth, powdered clay added to improve the texture.  

Lipstick
A blend of oils and waxes gives this product its smooth texture. Beeswax or carnuba wax are usually used, along with oils such as olive oil, cocoa butter, lanolin and petrolatum. A higher percentage of oils gives a glossier, more liquid product while extra wax adds staying power.  

Is this nano?
Want to verify that your nano-powered face cream is really all it claims? Check the ingredients listed on the packet. Crawford says, ‘An ingredient that conforms to the definition of a nanomaterial will be labelled with the word ‘nano’ in brackets after the ingredient name’.

 

In numbers

4,000 companies in the EU cosmetic industry
17,000 scientists employed in the sector
10% of all EU patents relate to cosmetics  


For more information, visit www.ctpa.org.uk or www.personalcareregulatory.eu