Surface-modified PET for cardiovascular applications: preliminary biocompatibility studies

Half of the annual human deaths worldwide are due to cardiovascular diseases [1]. Currently, synthetic grafts play a vital role in medicine, as implant demands exceed natural available sources and thus alternative solutions are needed. Poly(ethylene terephthalate) or PET is extensively used as a synthetic graft material on account of its excellent bulk properties (high mechanical and thermal properties) and chemical inertness. A major drawback is its poor surface properties that directly influence biological performance. Herein, we present a nature-inspired surface modification strategy suitable for fine-tuning surface properties of PET grafts. Materials & Methods. A two-step surface modification strategy was applied to PET (see Fig 1.). A dopamine-based coating procedure was used to facilitate the subsequent covalent immobilization of gelatin. In parallel, physisorbed surfaces were obtained by dip-coating. A surface characterization was performed using SCA, AFM and XPS, coupled with radiolabelling. Also, preliminary haemocompatibility and in vitro assays were applied. Fig. 1: Schematic representation of the general surface modification strategy. Results & Discussion. Current surface modification strategies consist either of complex multi-step and time-consuming steps or the use of compounds (e.g. glutaraldehyde) that can raise toxicity issues [3]. Therefore, most synthetic grafts are generally modified by a physical means, neglecting coating stability issues. To circumvent these problems, we have developed an easy aqueous-based Ti oxidation cleaning Ti OH OH OH OH Ti X X X X polymer immobilisation Ti functionalisation