L-Ascorbic acid and phosphatidylcholine complex vesicles: formation and elucidation of their biological activities, and their molecular interactions.

The aim is to prepare, characterise, and evaluate the biological activities and key molecular interactions of L-ascorbic acid and phosphatidylcholine (PC-AA) complex vesicles. PC-AA complexes were prepared and characterised using DLS, TEM, FTIR, UV-Vis, in-vitro release, bioactivities, and cytotoxicity. The key interactions of the AA with the PC were studied with MD simulations. PC-AA complex provides improved stability towards the degradation of AA in aqueous solutions while also slowing its release profile. The PC-AA complexes with an optimal molar ratio of PC: AA = 2.5:1 was shown to have a hydrodynamic diameter of 368.67 ± 4.65 nm and an EE of 68.16 ± 0.23%. At low concentration, the PC-AA complexes have no toxicity towards human dermal fibroblast cells over 48 h. Importantly, MD suggests that AA only forms the PC-AA complex when in its neutral form which is the desired active form. PC-AA complex could be a potential active to use in medicinal and cosmeceutical applications.

Development of Tea Seed Oil Nanostructured Lipid Carriers and In Vitro Studies on Their Applications in Inducing Human Hair Growth.

Synthetic drugs used to treat hair loss cause many side-effects. Natural tea seed oil possesses many activities that can suppress hair loss. However, it is oily and sticky in direct application. In this study, tea seed oil loaded nanostructured lipid carriers (NLC) using Tween 80 (NLC-T), Varisoft 442 (NLC-V), and a combination of both surfactants (NLC-C) was developed. The obtained nanoformulations showed spherical particles in the size range 130-430 nm. Particle size and size distribution of NLC-C and NLC-T after storage at 4, 25, and 40 °C for 90 days were unchanged, indicating their excellent stability. The pH of NLC-T, NLC-V, and NLC-C throughout 90 days remained at 3, 4, and 3.7, respectively. NLC-C showed significantly greater nontoxicity and growth-stimulating effect on human follicle dermal papilla (HFDP) cells than the intact oil. NLC-T and NLC-V could not stimulate cell growth and showed high cytotoxicity. NLC-C showed melting point at 52 ± 0.02 °C and its entrapment efficiency was 96.26 ± 2.26%. The prepared hair serum containing NLC-C showed better spreading throughout the formulation than that containing the intact oil. Using 5% NLC-C showed a 78.8% reduction in firmness of the hair serum while enhancing diffusion efficiency by reducing shear forces up to 81.4%. In conclusion, the developed NLC-C of tea seed oil is an effective alternative in stimulating hair growth. Hair serum containing NLC-C obviously reduces sticky, oily, and greasy feeling after use.