NANOSYSTEM SYNTHESIS BASED ON TETRACHLOROAURIC ACID AND CORNU ASPERSUM SNAIL MUCUS, IT’S INCORPORATION INTO COSMETIC PATCHES AND CLINICAL EVALUATION OF EFFICACY

Abstract

Gold nanosystems have been synthesized via reduction of tetrachloraurate by glycoproteins of the snail Cornu aspersum mucus. The optimal synthesis conditions, including reagents ratio, temperature, pH, time, mixing and settling conditions, were determined. The best results were obtained by using a freshly prepared 0.1 % aqueous solution of lyophilized snail mucus mixed with 0.5 mM/L HAuCl₄ solution in a 1:2 ratio at pH 12 and incubated under natural light for 24 hours. Spectrometric analysis confirmed the nanoparticles creation by recording a band of surface plasmon resonance at 550 nm. The antibacterial activity of the synthesized nanosystems was studied by disk diffusion assay, which revealed a bacteriostatic effect against the Gram-positive bacterium Bacillus subtilis. The three obtained nanosystems were integrated into the developed cosmetic product for skin care around the eyes – liquid patches. The original formulation of the product provides for a tonic, nourishing and moisturizing effect due to the active ingredients, such as caffeine (0.5 %), hyaluronic acid (0.5 %), galactomycetes filtrate (3 %) and fucogel polysaccharide (1 %). Clinical trials of the liquid patches were conducted for 21 days with 12 female volunteers. The skin condition was assessed using visual analysis and a portable skin analyzer CF-685 equipped by the camera that recorded changes in moisture, elasticity, pigmentation, and oiliness. It was found that the use of patches with gold nanosystems helps to increase skin moisture by 15–20 % and improve its elasticity by 10–12 %, which confirms their effectiveness as a care cosmetic product.