Mussel-inspired self-coating at macro-interface with improved biocompatibility and bioactivity via dopamine grafted heparin-like polymers and heparin

In this study, multifunctional mussel-inspired self-coated membranes with remarkable blood and cell compatibilities are prepared by a facile and green approach. A highly sulfonated linear heparin-like polymer (HepLP, poly(sodium 4-vinylbenzenesulfonate)-co-poly(sodium methacrylate)) and heparin are chosen for the mussel-inspired heparin-mimicking coating, respectively. Firstly, DA is grafted onto the backbone of HepLP or heparin to obtain DA grafted HepLP (DA-g-HepLP) or DA grafted heparin (DA-g-Hep) by means of the carbodiimide chemistry method. Then, the DA-g-HepLP and DA-g-Hep are used to prepare surface coated heparin-mimicking substrates; the polyethersulfone (PES) dialysis membrane is chosen as the model substrate. The coated surface composition, surface morphology, water contact angle, surface zeta-potential, blood compatibility and cell compatibility are systematically investigated. The results of surface spectra, scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicated that the DA-g-HepLP and DA-g-Hep were successfully coated onto the membranes. The coated membranes showed increased hydrophilicity and electronegativity, decreased plasma protein adsorption, and suppressed platelet adhesion compared to the pristine membrane. The cell morphology observation and cytotoxicity assays demonstrated that the surface coated heparin-mimicking membranes showed superior performance in endothelial cell proliferation and morphology differentiation. In addition, the excellent anticoagulant bioactivities indicated that the adhered DA-g-HepLP (or DA-g-Hep) could function or maintain its biological activity after the immobilization. In general, the mussel-inspired protocol of surface self-coating conferred the modified membranes with integrated blood compatibility, cell proliferation and biological activity for multi-biomedical applications, like hemodialysis, blood purification, organ implantation, and cell and tissue cultures.