Interaction of heparin with polyallylamine-immobilized surfaces

✍ Scribed by Ma, Xinghang ;Mohammad, Syed Fazal ;Kim, Sung Wan

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 860 KB
• Volume: 27
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.820270309

✦ Synopsis

A new method to bind ionically and remove heparin from solution and dilute serum is described. Utilizing cellulose diacetate (CA) as the polymer substrate, a cationic polymer chain-poly(ally1amine)-PALA-was immobilized directly onto the CA surface and onto the surface using poly(ethy1ene glycol) (PEG) spacer groups. The ionic interaction between the anionic heparin molecule and the cationic PALA polymer is specific and effective to remove heparin from the bulk solution. The binding properties of heparin onto the PALA and PEG-PALA surfaces were examined. The effects of PEG spacers on heparin binding onto the PALA-immobilized surface were investigated by varying the M, of PEG spacers. PALA (M, 8500)-immobilized surfaces exhibited enhanced heparin binding. The maximum heparin binding was observed in the region of PEG M, 2000-4000. For the high-molecular-weight PALA (M,,, 50,000)-immobilized surfaces, heparin binding was independent of the molecular weight of PEG. PEG spacers were also evaluated for their ability to prevent or decrease protein (albumin) adsorption. It was observed that at high albumin concentrations, the adsorption of proteins decreased with increasing chain length of PEG, up to M, 3400. These observations suggest that low-molecular-weight PALA (M, 8500)-immobilized CA surfaces with PEG spacers (M, 3400) may provide increased heparin binding capacity and decreased protein adsorption.