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Controlled release of heparin from polypyrrole‐poly(vinyl alcohol) assembly by electrical stimulation
Author(s) -
Li Yali,
Neoh K. G.,
Kang E. T.
Publication year - 2005
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.30286
Subject(s) - materials science , polypyrrole , vinyl alcohol , polymer chemistry , ethylene glycol , copolymer , substrate (aquarium) , dimethyl sulfoxide , covalent bond , scanning electron microscope , polyvinyl alcohol , chemical engineering , polymerization , polymer , organic chemistry , composite material , chemistry , oceanography , engineering , geology
A surface modification technique was developed for the covalent immobilization of poly(vinyl alcohol) (PVA)‐heparin hydrogel onto electrically conductive polypyrrole (PPY) film with the objective of achieving controlled release of heparin. First, aldehyde groups were introduced onto PPY film through poly(ethylene glycol) monomethacrylate graft copolymerization and subsequent oxidation in acetic anhydride and dimethyl sulfoxide mixture. Then, the prepared PVA‐heparin hydrogel was cast onto the PPY film and covalently immobilized to the film through the reaction between the aldehyde groups on the PPY film and the hydroxyl groups of PVA. X‐ray photoelectron spectroscopy was used to characterize the surface‐modified film after each stage. The strong attachment of the PVA‐heparin layer on the PPY film was confirmed by peel test and scanning electron microscopy. The release behavior of heparin from the substrate with and without electrical stimulation was studied and the experimental results showed that the heparin release rate from the prepared substrate using an electric current of 3.5 mA is twofold higher than that without current. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 73A: 171–181, 2005