Matrixyl

What is Matrixyl?

KTTKS is a pentapeptide subfragment of the propeptide of type I collagen. More specifically, it is the minimum sequence of this propeptide necessary to potently stimulate the production of collagen and fibronectin by human fibroblasts (R). The addition of palmitic acid to KTTKS forms palmitoyl-KTTKS, or pal-KTTKS (R).

Matrixyl, an active ingredient found in many anti-aging products, is a commercial solution containing 100 ppm of pal-KTTKS (R).

Is Matrixyl stable?

In an analysis of 6 commercial antiwrinkle products containing pal-KTTKS, over 90% of the expected concentration was found in 2, over 80% of the expected concentration was found in 3, but severe degradation of was observed in the last product, where only 24% of the expected concentration was detected. This indicates that the stability of the pal-KTTKS in Matrixyl is strongly influenced by the cosmetic formulation (R).

Does Matrixyl get absorbed?

KTTKS is hydrophilic and has a relatively high molecular weight, making it a poor candidate for topical delivery. The attachment of a lipophilic group in palmitic acid therefore serves to improve the delivery of KTTKS across the epidermis by enabling it to penetrate the stratum corneum barrier. Indeed, the calculated permeability coefficient of pal-KTTKS is 17 times higher than the predicted value for KTTKS, as the effect of the increased lipophilicity dominates over that of the increase in molecular weight (R).

1 study has claimed to have confirmed the penetration of KTTKS into full-thickness human skin ex vivo, but no data were presented (R). Typical concentrations used in cosmetic products are very low, purportedly between 2-8 ppm, as pal-KTTKS is extremely potent. This makes detection difficult, and may explain the paucity of published permeation data (R).

What happens after Matrixyl is absorbed?

Upon delivery into the skin, it is thought that pal-KTTKS may act as a prodrug, releasing the peptide KTTKS by enzymatic cleavage (R).