Examining polyquaternium polymers deposition on human excised hair fibers

Surface Activity of Surfactant–Polyelectrolyte Mixtures through Nanoplasmonic Sensing Technology

Deposition plays an important role in the active delivery and efficiency of hair and skin formulations since it allows active compounds to interact with surfaces in order to achieve the product’s desired performance characteristics. Therefore, it is essential to study the surface activity and behavior of certain compounds that are frequently used in cosmetic and pharmaceutical formulations in order to understand how they interact with relevant biological surfaces, such as hair and skin. We chose to study the surfactants and conditioning agents utilized in the formulation of conditioning shampoos, which are usually designed to be able to achieve the deposition of these substances on the hair and scalp to provide lubrication and better conditioning for hair fibers, facilitating detangling and providing a better feel. In this study, cationic polymer and salt fractions were varied to obtain eighteen different conditioning shampoo formulations in which the deposition was measured by utilizing a nanoplasmonic sensing technology instrument. Moreover, a wet combing test was performed for each of the formulations to investigate if there was any correlation between the combing force and the surface deposition. The complete study was performed using a sustainable anionic surfactant in order to compare the results with those obtained from the traditional formulations.

Argan oil as a pretreatment of human hair before exposure to oxidative damage: Attenuated total reflectance and protein loss studies

INTRODUCTION

In recent years, argan oil has gained increasing interest in hair care products. In this study, attenuated total reflectance technique was utilized as a fast method and the results were compared to protein loss measurements in order to show the preventive effect of argan oil pre-treatment on excised human hair after oxidative hair damage.

METHODS

Hair tresses were divided into three groups: in group-1; they were damaged using oxidant agent solely, in group-2 and 3; hair were pre-treated with argan oil before undergoing the oxidative damage. In group-2, the oil was removed by physical cleaning but in group-3 the oil was removed with a washing procedure. ATR (attenuated total reflectance) spectrum was recorded for different samples. Quantitative studies of protein loss in hair samples were performed by Lowry method. The antioxidant properties of argan oil were also measured in vitro using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) protocol, which determined the ability of the oil to scavenge the DPPH free radicals.

RESULTS

The amount of protein loss with oil pre-treated groups was reduced significantly. The ATR spectrum showed oil deposition on hair even after washing. Four distinctive ATR peaks were changed during oxidation. The changes in peak height values were linear. The antioxidant property measured with DPPH method led to a IC50 value of 59 µg/ml.

CONCLUSION

Argan oil pre-treatment was effective in protecting hair against oxidative damage. ATR outcomes were in accordance with protein loss results. In this study, the ATR testing method as a fast technique was used efficiently in quantification of hair damage.

Polyquaternium enhances the colloidal stability of chitosan-capped platinum nanoparticles and their antibacterial activity

Here, for the first time, we have developed a novel green synthesis method where chitosan acts as a reducing agent and as a colloidal stabilizer, together with polyquaternium for the synthesis of platinum nanoparticles (PtNPs). It was observed that only chitosan-stabilized PtNPs (Ch@PtNPs) were stable up to pH 5, with a diameter of around 89 nm. The diameter of the Ch@PtNPs increased with the increase in pH, indicating the instability of Ch@PtNPs at neutral and alkaline mediums. However, when polyquaternium (PQ) (a cationic polymer) was added as a stabilizer along with chitosan, the diameter of chitosan/polyquaternium stabilized PtNPs (Ch/PQ@PtNPs), i.e. 87 nm, remained almost constant up to pH 9. Similarly, the pH-dependent decrease in the surface charge of Ch@PtNPs was also attenuated with the addition of polyquaternium. This indicates high colloidal stability of Ch/PQ@PtNPs in acidic, neutral, as well as alkaline mediums. It was observed that Ch/PQ@PtNPs exhibited high antibacterial activity againstStaphylococcus aureus, as compared to uncapped PtNPs and Ch@PtNPs. Thus, the addition of PQ increases the antibacterial properties of Ch/PQ@PtNPs againstStaphylococcus aureusby enhancing the stability of PtNPs at neutral pH.