Development and In Vitro Characterization of Hyaluronic Acid-Based Coatings for Implant-Associated Local Drug Delivery Systems

Figure 1

Reaction scheme for chemical attachment of a HA base layer to PA12 surfaces via (a) O₂-plasma treatment, silanization with (b) APTES or (c) GPTMS, and covalent binding of HA via (d) activation of the carboxylic acid of HA with EDC/NHS and subsequent reaction with terminal amine groups on the APTES-modified PA12 surface or via (e) direct reaction of terminal epoxy groups at the GPTMS-modified PA12 surface and hydroxyl groups of HA.