Methylcobalamin-loaded ultra-flexible liposomes: a nanocarrier approach for modulating melanocyte homeostasis and addressing pigmentation imbalances.

Although various therapeutic approaches have been developed for hyperpigmentation, the reliability and efficacy of these treatments remain controversial. This study investigates the effect of methylcobalamin encapsulated in ultra-flexible liposomes on melanocyte homeostasis and evaluates its antioxidant potential for treating pigmentation disorders. Ultra-flexible liposomes with a final lipid concentration of 10 mM were prepared using soy phosphatidylcholine and sodium cholate via the thin-film hydration method. The particle sizes of blank and methylcobalamin-loaded liposomes were 118 ± 9 nm and 124 ± 3 nm, respectively, demonstrating their suitability for in vitro drug release, permeability studies and biomedical applications. Dynamic Light Scattering analysis confirmed the formation of ultra-flexible liposomes with a negative surface charge, similar to cell membranes. Stability studies showed that both particle size and zeta potential remained stable for up to 4 weeks, indicating the structural integrity of the formulation. Approximately 70 % of the encapsulated methylcobalamin was released within 24 h, with an encapsulation efficiency of around 42 %. These liposomes, with a deformability index close to 1, penetrated deeper into the epidermis and dermis of porcine ear skin compared to the free drug. Cell culture studies demonstrated the biocompatibility of the liposomes, with no cytotoxic effects on human dermal fibroblasts and a high uptake rate by human dermal melanocytes. In vitro experiments on melanocyte cells showed a reduction in melanin content, tyrosinase activity, and reactive oxygen species levels, indicating the antioxidant potential of methylcobalamin. In conclusion, methylcobalamin-loaded ultra-flexible liposomes appear to be promising nanocarriers for the targeted treatment of pigmentation disorders.