Electroactive Hydrophilic Polylactide Surface by Covalent Modification with Tetraaniline

Covalent surface functionalization is presented as a versatile tool to increase the hydrophilicity and to introduce the electroactivity of polyester films. Acrylic acid and maleic anhydride were photografted onto a polylactide (PLA) surface with a "grafting from" method to increase the surface wettability, and the subsequent coupling of conductive aniline oligomer was used to introduce electroactivity to the PLA surface. The photopolymerization of maleic anhydride and acrylic acid and the coupling, of aniline tetramer (AT) were characterized by FT-IR, UV, and TGA. The surface morphology of the PLA surface before and after modification was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). A medium hydrophilic surface of PLA was achieved by surface modification with maleic anhydride, acrylic acid, and AT. An electrically conductive surface was obtained after grafting with AT, and the conductivity increased with increasing AT content on the surface. The hydrophilic and electroactive surface of polyesters while retaining their bulk properties offers new possibilities in biomedical applications, such as bone, cartilage, neural, and cardiovascular tissue engineering.