Construction of antithrombogenic polyelectrolyte multilayer on thermoplastic polyurethane via layer‐by‐layer self‐assembly technique

Abstract The improvement of hydrophilicity and hemocompatibility of thermoplastic polyurethane (TPU) film was developed using surface modification of polyelectrolyte multilayers (PEMs) deposition. The polysaccharide PEMs included chitosan (CS, as a positive‐charged agent) and dextran sulfate (DS, as a negative‐charged and an antiadhesive agent) that were successfully prepared on the aminolyzed TPU film in a layer‐by‐layer (LBL) self‐assembly manner. X‐ray photoelectron spectroscopy (XPS), field‐emission scanning electronic microscopy (FE‐SEM), and atomic force microscopy (AFM) data will verify the progressive buildup of the PEMs film. The obtained results showed that the contact angle and Zeta‐potential reached the steady value after four bilayers of coating, hence proving that the full coverage of coating with PEM layers was achieved. It could be found that the PEMs‐deposited TPU films with DS as the outmost layer could resist the platelet adhesion and human plasma fibrinogen (HPF) adsorption, thereby prolonging effectively the blood coagulation times. Besides, the results of growth inhibition index (GI) of L929 fibroblast proliferation suggested that the as‐fabricated TPU films were noncytotoxic. Overall results demonstrated that such an easy, valid, shape‐independent, and noncytotoxic processing should be potential for the ion of TPU substrate in the application of hemodialysis or cardiovascular devices. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007