Written by Paul Fister, 2009.
As the global cosmetic industry is progressively moving towards pharma-like behaviour, the issue of safety and not just efficacy is becoming a growing concern. This concern is driven by public demand and is currently researched in greater depth by manufacturers.
One example is nanotechnology, that can deliver both synthetic and natural ingredients to deeper layers of the skin, targeting and stimulating skin components that will minimise the impact of ageing and contribute to more robust skin integrity, resulting in a younger-looking appearance. Anti-ageing, skin-barrier function and in particular ingredients that have the ability to harness and reverse the ageing process appear to be the land of opportunity for skincare technology. But how safe are these ingredients and their delivery systems through long-term use? Even though small quantities are considered safe, how will their cumulative effect impact the health of the body? These are pressing questions that are currently being investigated.
Meanwhile, biomimetics has a long-standing novel approach to achieving optimal skin vitality through a less invasive, yet effective manner. A recent report on global trends presented by CosmeticDesign-Europe brought to light how biomimetic peptides and other natural ingredients are achieving great results, drawing renewed focus on the effectiveness of the biomimetic concept in skincare formulations and how they can meet with current consumer expectations.
As with every industry, skincare is also driven by product innovations that often determine trends. The pathways to younger-looking skin can be achieved through various means — chemical peels, photodynamic therapy, microdermabrasion, microcurrents, ultrasound and radiofrequency, just to name a few. While many of these methods utilise controlled trauma and induced inflammation, others offer results through a less-aggressive pathway. Each have their rationale and often we are inclined to embrace those that offer the greatest commercial appeal. As professionals, however, it is our responsibility to investigate the various options available to us and determine our choices based on independent scientific studies and our convictions on what we believe can offer us the best possible results.
A Biomimetic Approach to Skincare
The term ‘biomimetic’ has in recent years come to the attention of the cosmetic industry. It is a combination of the words bios, meaning life, and mimesis, which means to imitate. In other words, biomimetics refers to science that focuses on imitating nature’s methods, designs and processes.
Why would we want to copy nature? Scientists have discovered that, through millions of years of evolution, nature has created a vast range of highly effective solutions. Processes developed through evolution invariably achieve the highest possible output for minimal input. A well-known example is Velcro, an idea that came to Swiss inventor George de Mestral after he got curious about the reason why cockleburs clung so stubbornly to his dog’s fur.
For a successful biomimetic solution we need to first study and develop a deep understanding of the natural processes we wish to imitate. Deviations from the natural model will lead to less than optimal outcomes. This rule also applies to cosmetic products.
What is not Biomimetics
A superficial approach to biomimetics in skincare is to select some ingredients known to form part of the skin’s acid mantle, add them to a skincare cream and then call the cream ‘biomimetic’. That’s like adding a petrol tank to your bicycle and then calling it a motorbike. A true biomimetic approach goes deeper than that.
Our skin’s acid mantle has been studied in great detail. Within the epidermis we find lipid bilayers that bind water. Our sebaceous glands supply lipids to the skin’s surface, which forms part of the acid mantle. These lipids include squalane, ceramides, sterols, cholesterol and EFAs (essential fatty acids). Chemical components of the acid mantle called NMFs (Natural Moisturising Factors) include Sodium PCA, Urea, Amino Acids, Lactates and more. A formulator adding any of these ingredients to their skincare cream may decide to call the final product ‘biomimetic’, but is the end product a true biomimetic skincare?
This approach misses a large step to a truly biomimetic solution. It focuses on ingredients and doesn’t take into account the structure of the skin’s natural acid mantle. Our epidermis must contain a minimum of 10% water to be and to appear healthy. It is the oil content of the acid mantle that ensures that these levels of moisture are maintained.
Clarifying the Definition and What It Means for the Skin
Expert formulators like Dr. Horst Spiller have recognised that for a product to be truly biomimetic it needs to emulate the type of emulsion produced naturally on our skin. Our natural acid mantle in fact takes the form of a water-in-oil emulsion. Cosmetic chemist and author Florence Barrett-Hill refers to this phenomenon as ‘oil sitting on top of water’. This makes sense, since water sitting on the surface and therefore exposed to the air will quickly evaporate. This suggests that a truly biomimetic skincare cream must be classified as a ‘water-in-oil’ formulation, or, an oil-based formulation.
True to the theory that nature’s processes achieve the highest possible result for minimum effort, such a biomimetic emulsion shows several distinct advantages over the more common water-based creams or oil-in-water formulations. These advantages centre around potentially damaging ingredients as well as overall performance of the cream.
Oil and water can only be combined into a cream with the use of emulsifiers. These emulsifiers are known to be potentially damaging as they can emulsify the skin’s barrier lipids and strip or disturb its natural protection against dehydration. Water-in-oil, or oil-based, cream can be formulated with significantly less potent emulsifiers that do not strip the skin’s acid mantle of its oils. Emulsifiers are classified according to their HLB-value (hydro-lipid balance value). Emulsifiers used in oil-based creams typically have a value around 3-6. Those used in water-based creams often have values from 8 up to 15 and higher. These values are in the same category as soap.
Preservatives
A three-year shelf life, as required by law, can only be achieved with the use of preservatives. These, like emulsifiers, are foreign to the skin and can be a source of skin irritations. Preservatives are designed to control contamination of the product. Bacteria thrive in a water-based environment, and therefore water-based creams require significant levels of preservation. An oil-based environment is not conducive to bacterial proliferation. Biomimetics therefore dictate that an oil-based cream can be formulated with significantly lower levels of preservation ingredients.
Another proven advantage is the delivery of active ingredients. A study conducted by T. Foerster of Henkel KgA shows that significantly greater penetration of the important antioxidant Vitamin E is achieved with oil-based creams compared to a water-based one. Oil-based creams readily mix with the sebum in the skin’s acid mantle and are therefore a superior delivery mechanism for a large range of actives.
And finally, oil-based creams offer superior hydration properties to the skin. Being biomimetically similar to the skin’s natural acid mantle they quickly replenish and re-establish the skin’s natural protection, reducing TEWL (transepidermal water loss) to a normal, healthy level and therefore ensuring hydration of the skin over several hours. This is a significant advancement on the hydration capabilities of most water-based creams, as demonstrated by German dermatologist Christel Bienstein and her colleagues.
A biomimetic approach offers significant advancements in the care of the skin. Further study of structure and functions of the skin, combined with improvements in emulsion and formulation technology, will undoubtedly lead to even better solutions in biomimetic skin care.
