title: Physicochemical and blood compatibility characterization of polypyrrole surface functionalized with heparin.
abstract: A surface modification technique was developed for the covalent immobilization of heparin onto electrically conductive polypyrrole (PPY) film. The PPY film was first graft copolymerized with poly(ethylene glycol) methacrylate (PEGMA) and then activated with cyanuric chloride (CC). Heparin was then immobilized onto the film through the reaction between the chloride groups of CC and the amine and/or hydroxyl groups of heparin. X-ray photoelectron spectroscopy (XPS) was used to characterize the surface-modified film after each stage. The biocompatibility of the surface-modified PPY was evaluated using plasma recalcification time (PRT) and platelet adhesion. After surface modification, the film had improved wettability while retaining significant electrical conductivity. With immobilized heparin, platelet adhesion and platelet activation on PPY film was significantly suppressed, and the PRT was significantly prolonged. Electrical stimulation also plays a positive role in decreasing platelet adhesion and increasing PRT on pristine and surface-modified PPY films.
authors.affiliation: Department of Chemical and Environmental Engineering, National University of Singapore, Kent Ridge, Singapore 119260, Republic of Singapore.
authors.forename: Yali
authors.initials: Y
authors.lastname: Li
authors.forename: Koon Gee
authors.initials: KG
authors.lastname: Neoh
authors.forename: Lian
authors.initials: L
authors.lastname: Cen
authors.forename: En-Tong
authors.initials: ET
authors.lastname: Kang
mesh_terms: D000327:Adsorption; D000818:Animals; D001792:Blood Platelets / Q000502:physiology / Q000648:ultrastructure*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006493:Heparin / Q000097:blood / Q000737:chemistry*; D008422:Materials Testing; D008567:Membranes, Artificial; D015539:Platelet Activation / Q000502:physiology*; D010973:Platelet Adhesiveness / Q000502:physiology*; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D011817:Rabbits; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D008567:Membranes, Artificial; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D006493:Heparin