Abstract
BACKGROUND: Hyaluronate (HA) is widely utilized in skin rejuvenation treatments, yet mono-component injectable sodium hyaluronate solution (ISHA) is limited by its modest moisturizing performance and frequent dosing requirements. The combination of HA with active ingredients such as amino acids represent a promising strategy to improve hydration efficacy. AIMS: This study aimed to develop a novel injectable sodium hyaluronate composite solution (Co-ISHA) incorporating three amino acids-glycine, alanine, and proline-and to systematically evaluate its moisturizing effects through phenomenological and mechanistic analyses at cellular and tissue levels. METHODS: This study developed a novel Co-ISHA containing glycine, alanine, and proline, and evaluated its moisturizing performance through a comprehensive in vitro assessment system. The reparative and protective effects of Co-HA on cells and tissues under dry conditions were examined, along with the expression of moisturizing-related genes and natural moisturizing factors (NMF). This system integrated both cellular and tissue-level models to elucidate the underlying mechanisms. RESULTS: The results indicated that the addition of these three amino acids significantly enhanced the moisturizing efficacy of hyaluronic acid (HA). Both cellular and tissue-level evidence confirmed that, compared to single-component HA, Co-ISHA more effectively protected and repaired cells damaged by dryness and promoted the production of moisturizing-related genes and NMF. CONCLUSION: This study successfully developed a Co-ISHA formulation with superior moisturizing properties and established a robust in vitro evaluation system for assessing hydration efficacy. The findings provide a strategic framework for advancing the development of "Cruelty-Free" cosmetic products.