Branched Hyaluronic Acid for Reduced Viscosity and Enhanced Moisturization

Despite its remarkable moisturizing properties, the inherently high viscosity of high-molecular-weight hyaluronic acid (HA) restricts its practical application in skincare products, cosmetic formulations, and skin-contact medical devices. To overcome this limitation, we propose the incorporation of branched structures into HA to create a branched HA hybrid (bHH) by chemically coupling low-molecular-weight HA (200 kDa) with high-molecular-weight HA (700–2500 kDa). The introduction of branched structures into the HA backbone alters the viscosity of high-molecular-weight HA while preserving its moisturizing potential. Branching reduces the solution viscosity of linear HA, particularly at higher polymer concentrations. In this study, the moisturizing efficacies of branched and linear HAs were extensively evaluated. Branched HA demonstrated equivalent or superior moisturizing effectiveness compared with linear HA and even significantly enhanced the water-binding capacity over simple mixtures of linear HAs. These findings suggest that introducing branched structures can effectively reduce the solution viscosity of linear HA without compromising its moisturizing properties, thereby improving the usability and hydration performance of skincare products and skin-contact devices.