Keratin-based particles for protection and restoration of hair properties

Abstract

Objective Human hair is an element with unquestionable relevance in society both for women and men. Therefore, it is of great importance to develop new cosmetic products for hair care capable to restore and improve hair's characteristics. Here we explore the potential of keratinbased particles in the protection and recovery of hair mechanical properties and thermal stability. Methods Keratinbased particles were obtained by high pressure homogenization (HPH) using keratin and silk fibroin. The particles were characterized regarding size, superficial charge and polydispersity index. Their safety to cells was assessed using human skin keratinocytes. Virgin and overbleached Asian hair were treated with eight keratinbased formulations. The effect of particles on hair's mechanical properties was evaluated in terms of stiffness and tensile strength. The impact of treatments in hair thermal performance was studied using differential scanning calorimetry (DSC). Results Keratinbased particles were capable to recover and/or improve the mechanical properties of virgin and overbleached hair. Virgin hair treated with K80SF20P particles presented an improvement of the mechanical properties around 40%. An increase in keratin helix denaturation enthalpy and in surface smoothness for both types of hair was also verified after treatment. These particles demonstrated stability over time and proved to be safe when tested in human keratinocytes. Conclusion The keratinbased particles here presented have the potential to be incorporated in the development of new and effective hair care cosmetic formulations.