Ionically cross-linked hyaluronic acid: wetting, lubrication, and viscoelasticity of a modified adhesion barrier gel

Katherine Vorvolakos¹, Irada S Isayeva¹, Hoan-My Do Luu¹, Dinesh V Patwardhan¹, Steven K Pollack^2
1Division of Chemistry and Material Science, ²Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD, USA

Abstract: Hyaluronic acid (HA), in linear or cross-linked form, is a common component of cosmetics, personal care products, combination medical products, and medical devices. In all cases, the ability of the HA solution or gel to wet surfaces and/or disrupt and lubricate interfaces is a limiting feature of its mechanism of action. We synthesized ferric ion–cross-linked networks of HA based on an adhesion barrier, varied the degree of cross-linking, and performed wetting goniometry, viscometry, and dynamic mechanical analysis. As cross-linking increases, so do contact angle, viscosity, storage modulus, and loss modulus; thus, wetting and lubrication are compromised. These findings have implications in medical device materials, such as adhesion barriers and mucosal drug delivery vehicles.

Keywords: hyaluron, adhesion barrier, wetting, contact angle, viscosity, lubrication, elasticity, viscoelastic, hydrogel, ferric