Surface modification of PET films using pulsed AC plasma polymerisation aimed at preventing protein adsorption

We utilise pulsed AC plasma polymerisation to create thin films that either contain reactive acid functional groups (by deposition of maleic anhydride (MAH) followed by hydrolysis) or are poly (ethylene glycol) (PEG)-like in nature (by using diethylene glycol vinyl ether (DEGVE) as monometer). The MAH films were further modified with PEG chains using a two-step wet chemical method. For the DEGVE films the plasma power was varied in order to change the degree of monomer fragmentation and thus retention of PEG-like character. The chemistry of the surfaces was determined using Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectroscopy (ToF SIMS). Significant reduction (up to 90%) in protein adsorption was achieved by the plasma polymer surfaces as determined using ¹²⁵I-radiolabelled fibrinogen adsorption experiments.