Tripeptide-Loaded Liposomes as Multifunctional Components in Topical Formulations

Modern dermocosmetics combine the effectiveness of active substances with the benefits of percutaneous penetration enhancers to address skin issues such as hyperpigmentation. In this study, three bioactive tripeptides (with amino acid sequences CSF, CVL, and CSN) with previously confirmed tyrosinase inhibition activity were synthesized using the solid-phase synthesis method. The structures of the obtained peptides were determined. In addition, elastase in silico and in vitro inhibition assays were carried out. The tripeptides were subsequently encapsulated into liposomes, for which key physicochemical parameters were determined, including size, zeta potential, and encapsulation efficiency. The average diameter of the prepared liposomes was approximately 100 nm across all samples. The prepared carriers were found to be stable and exhibited no cytotoxicity toward reconstructed human epidermis cells. The peptides achieved an encapsulation efficiency of approximately 20-30%, with no significant differences observed between the cationic and anionic vesicles. Liposomes containing the CSF tripeptide, which showed the strongest tyrosinase-inhibiting effect, did not transport the peptide through the human skin in an ex vivo assay to permit quantification in the receptor solution, but facilitated penetration and retention of the tripeptide within the epidermis (4.65 ± 1.81 μg/cm²). These findings suggest that the prepared liposomes may serve as valuable carriers of bioactive tripeptides in anti-aging cosmetics.