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Abstract: This work described the graft polymerization of a sulfonic acid terminated monomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), onto the surface of polypropylene non-woven (NWF PP) membrane by O2 plasma pretreatment and UV-induced photografting method. The chemical structure and composition of the modified surfaces were analyzed by FTIR-ATR and XPS, respectively. The wettability was investigated by water contact angle and equilibrium water adsorption. And the biocompatibility of the modified NWF PP membranes was evaluated by protein adsorption and platelet adhesion. It was found that the graft density increased with prolonging UV irradiation time and increasing AMPS concentration; the water contact angles of the membranes decreased from 124° to 26° with the increasing grafting density of poly(AMPS) from 0 to 884.2μgcm−2, while the equilibrium water adsorption raised from 5wt% to 75wt%; the protein absorption was effectively suppressed with the introduction of poly(AMPS) even at the low grafting density (132.4μgcm−2); the number of platelets adhering to the modified membrane was dramatically reduced when compared with that on its virgin surface. These results indicated that surface modification of NWF PP membrane with AMPS was a facile approach to construct biocompatible surface. [Copyright &y& Elsevier]

Abstract: Polypropylene (PP) was modified with 2-hydroxyethyl acrylate (HEA) by solution radical grafting to introduce active hydroxyl groups on polypropylene backbone (PP-g-HEA). Then the biomimic monomer, 2-methacryloyloxyethyl phosphorycholine (MPC), was grafted onto the surface of PP-g-HEA film (PP-g-HEA-g-MPC) by redox graft polymerizations with ceric(IV) ammonium nitrate as an initiator. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) showed that the HEA and MPC were introduced onto PP molecular chains and the copolymer, PP-g-HEA-g-MPC were formed. The water contact angle measurements demonstrated that the final modified PP film exhibited a better hydrophilic surface compared to the neat PP film. The platelets adhesion on the neat PP, PP-g-HEA and PP-g-HEA-g-MPC film was examined by scanning electron microscopy (SEM). It was found that a large number of platelets were adhered and activated on the surface of neat PP and PP-g-HEA films, while the number of platelets on PP-g-HEA-g-MPC surface was decreased remarkably. The result revealed that the introduction of poly(MPC) onto the PP surface improved the hemocompatibility of PP substantially. [Copyright &y& Elsevier]

Abstract: We described a two-step process to fabricate the heparinized polypropylene (PP) film using cyanuric chloride (CC) as a trifunctional reagent and poly (ethylene glycol) methacrylate (PEGMA) as a spacer. The modified PP films were characterized by attenuated total reflectance FT-IR and X-ray photoelectron spectroscopy; the content of PEGMA and heparin were determined by gravimetric method and a toluidine blue assay, respectively. For the PP-g-PEGMA films, it was found that small size protein BSA tended to adsorb on the surface of low molecular weight monomer grafted PP, whereas big spindle-shaped fibrinogen tended to adsorb on the surface of high molecular weight monomer grafted PP. We gave a definition of anti-protein adsorptive factor r with two model proteins, albumin and fibrinogen. The results by platelet adhesion and plasma recalcification time (PRT) experiments indicated that the factor r could be used to quantitatively evaluate the anticoagulant tendency of PP-g-PEGMA modified films. For the PP-g-PEGMA-g-heparin modified films, the surface was proved to have a high bioactivity by the adsorption of AT III assay and very low platelet adhesion. It indicated that immobilization of heparin on the PP film with PEGMA as a spacer was an effective way to improve the hemocompatibility of PP. [Copyright &y& Elsevier]