Biomimetic Boosters

Peptides are nowadays known to be one of the miracle skincare ingredients and the key to a successful cosmetic product. According to Mintel, up to 2,000 new skincare products containing peptides are launched every year around the world. Several popular brands rely on peptides in their formula and dermatologists vouch for them. Their touted spectrum of effects ranges from anti-wrinkle via anti-dark circles to the restoration of the original hair pigmentation. 

Understanding peptides

Peptides, like proteins, are composed of amino acids (AA), but fewer of them: Proteins can consist of hundreds of AA, whereas peptides are made of 2 up to 40 AA¹. Peptides in cosmetic applications often comprise of a maximum of 20 AA, with many peptides being only 2 up to 6 AA long².

How can these short AA sequences have an effect and make a difference? The devil lies in the details. Only very few selected peptide sequences can turn on the body’s own machinery and trigger skin cells to activate cellular metabolism. The challenge for scientists is to identify these few peptides through sophisticated screenings. It is not uncommon for hundreds of AA sequences to be analysed and tested to obtain only one peptide that emerges as a suitable active candidate³. 

The starting point in the search for an active peptide is in many cases the AA sequence of a skin matrix protein itself. This can be explained by the neosynthesis being closely linked to the degradation processes of the same structures through feedback mechanisms. Selected peptides resulting from the degradation of matrix proteins can, in turn, initiate the natural reconstruction of the skin tissue by binding to specific cell receptors.

To illustrate, it resembles a lock-and-key model: it requires a peptide with a specific ‘AA code sequence’ to bind to key cell structures. This ‘docking’ activates corresponding pathways that lead to the production of proteins such as collagen, elastin, or hyaluronic acid.

Skin’s natural messengers

The peptides derived from the extracellular matrix that regulate cellular activities are also known as matrikines. In 1999, the term was coined by Professor Maquart and his team who published an article on this concept⁴. It is a blend of the words ‘matrix’ and ‘kinein’ (Greek: to move, to change) which describes their role very well: they are molecular messengers that initiate changes in the matrix. 

Another term used in connection with peptides is biomimetic (Greek: bios = life; mimetic = imitative). The rationale behind this is that peptides in cosmetics ‘mimic’ the peptides naturally present in the human body and thus potentially also imitate their natural mechanisms of action. To a certain extent, biomimetic peptides can therefore be considered ‘natural’ active ingredients.

The bioavailability of pure peptides is low; the watersoluble molecules hardly penetrate the stratum corneum. To optimise the bioavailability of peptides for topical applications, they are coupled to a long chain fatty acid. Modifications are declared in the INCI by a preceding ‘Palmitoyl-’ or ‘Biotinyl-’. The lipophilic group ensures that the peptides diffuse into the stratum corneum and the epidermal and dermal skin layers⁵.

Peptide pioneer

Launched in 2000 after seven years of research, Palmitoyl Pentapeptide-46 was the first peptide to be used in personal care applications. It is considered a breakthrough in the cosmetics industry and in 2015 has been awarded by over a thousand show visitors and a panel of industry experts as the product with the greatest impact on the personal care ingredients market in the last quarter century. Not surprising, as the peptide was shown to be more effective than vitamin C and as effective as retinol in wrinkle reduction. 

Its iconic status also becomes evident when you search for it in Google or look at market examples. According to Mintel, over 1,500 products across the globe trust this peptide pioneer in their skincare formulas and claim the tradename on their packaging⁷. Since 2000, its range has been expanded with three products that are also very successful⁸. A research paper showed that the peptides Palmitoyl Tetrapeptide-7 and Palmitoyl Tripeptide-19 along with two other peptides were among the most used peptides in anti-ageing cosmetics in 2018².

Two more types, launched in 2010 and 2017, were developed by thinking beyond and considering the complexity of natural peptides. The first¹⁰ is based on a dioxygenated natural peptide, meaning it has a side chain modification which can also be naturally present and has been proven more effective than the unmodified peptide. Convincingly, it was demonstrated to stimulate the synthesis of six major constituents of the skin matrix and dermal-epidermal junction (collagen I, III, IV, fibronectin, hyaluronic acid, and laminin 5). The second¹¹ on the other hand, is the first peptide to feature a cyclic AA side chain expansion inspired by the crosslink structure of various collagens found in the human body. It has been shown to support the reduction of vertical lines after just six weeks of use (figure 1).

Benefits

The most important advantages for the consumers are, of course, the skin benefits. Peptides are effective and, in some cases, already show first visible results after only two weeks of use. And after 2-6 months, truly amazing results can be achieved.

In addition to cosmetic efficacy, however, a major requirement for active ingredients is that they are safe to use. Accordingly, all peptide ingredients from our company go through rigorous testing on skin cells in the lab and in clinical studies before being launched. The safety of peptides used in cosmetics is substantiated by a review in 2012 that found no data on toxicity, carcinogenicity, skin irritation and sensitisation of palmitoyl peptides in the published literature¹³. Furthermore, in a safety assessment of 18 protein hydrolysates containing bioactive peptides, a panel concluded that all were safe to use in cosmetics at the described practices and concentrations¹⁴. Overall, peptides can therefore be considered perfectly safe for use in cosmetics.

An additional benefit for formulators is that peptides are easy to work with and add to a pre existing formula. However, the pH value should be considered, as it can have a considerable influence on peptide stability. The spectrum in which incorporation is possible is usually favourable at pH values between 4 and 9.

Next steps

Peptides show a broad spectrum of activity and are recognised safe for use in cosmetics. They are relatively new to the cosmetic market when compared, for example, to well-known ingredients such as retinol, which was first used in dermatology as early as 1943 for the treatment of acne vulgaris¹⁵.

But unlike the example of retinol, peptides are not just ‘one ingredient’. There are now a variety of different peptides available that offer different beauty benefits. The forward thinking in the development of new types has shown that even a decade on, the potential for innovation in this field has not yet been fully exploited, which is why one can look forward with excitement to the future, as it can be expected that perhaps even more effective peptides will be launched in the coming years.

References

¹ Office of the Federal Register, National Archives and Records Administration. 85 FR 10057 - Definition of the Term “Biological Product”. Office of the Federal Register, National Archives and Records Administration, 21 Feb 2020, https://www.govinfo.gov/app/details/FR-2020-02-21/2020-03505
² Ferreira MS, Magalhães MC, Sousa-Lobo JM, Almeida IF. Trending Anti-Aging Peptides. Cosmetics. 2020; 7(4):91. doi:10.3390/cosmetics7040091
³ Leroux R, Ringenbach C, Marchand T, Peschard O, Mondon P, Criton P. A new matrikine-derived peptide up-regulates longevity genes for improving extracellular matrix architecture and connections of dermal cell with its matrix. Int J Cosmet Sci. 2020;42(1):53-59. doi:10.1111/ics.12584
⁴ Maquart FX, Siméon A, Pasco S, Monboisse JC. Régulation de l’activité cellulaire par la matrice extracelulaire: le concept de matrikines [Regulation of cell activity by the extracellular matrix: the concept of matrikines]. J Soc Biol. 1999;193(4-5):423-428.
⁵ Lintner K, Peschard O. Biologically active peptides: from a laboratory bench curiosity to a functional skin care product. Int J Cosmet Sci. 2000;22(3):207-218. doi:10.1046/j.1467-2494.2000.00010.x
⁶ Matrixyl
⁷ Mintel GNPD; Status October 2021.
⁸ Matrixyl 3000 (Palmitoyl Tetrapeptide-7 and Palmitoyl Tripeptide-1), Matrixyl Snthe’6 and Matrixyl Morphomics
⁹ Matrixyl 3000
¹⁰ Matrixyl Synthe’
¹¹ Matrixyl Morphomics
¹² BB-Biont
¹³ Klaassen CD. Safety Assessment of Palmitoyl Oligopeptides as Used in Cosmetics Status : Scientific Literature Review Release 2012.
¹⁴ Burnett CL, Boyer IJ, Bergfeld WF, et al. Safety Assessment of Plant-Derived Proteins and Peptides as Used in Cosmetics. International Journal of Toxicology. May 2022. doi:10.1177/10915818221100700
¹⁵ Straumfjord, JV. Vitamin A: its effect on acne. Northwest Med 1943; 42: 219-225.