AVS 46th International Symposium
    Biomaterial Interfaces Group Tuesday Sessions
       Session BI-TuP

Paper BI-TuP7
Thin Films of Functionalized Poly(Ethylene Gylcol) for the Specific Attachment of Proteins

Tuesday, October 26, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: S.N. Xia, University of Washington
Authors: S.N. Xia, University of Washington
H.B. Lu, University of Washington
C.T. Campbell, University of Washington
D.G. Castner, University of Washington
Correspondent: Click to Email
The formation of ultrathin monolayers (10-30 angstroms thickness) of functionalized poly(ethylene gylcol) (PEG) oligomers and PEG-grafted siloxane polymers on gold surfaces has been investigated using x-ray photelectron spectrsocopy (XPS), static time of flight secondary ion mass spectromety (ToF SIMS), and surface plasmon resonance (SPR). PEG chains (MW 2000 to 5000) with an orthopyridyl-disulfide (OPSS) terminal group could be directly attached to a gold surface via formation of a gold-thiolate bond. By varying the type of terminal group at the other end of the PEG chain, the PEG monolayer can inhibit protein adsorption (OCH3), selectively attach proteins with surface cysteines (OPSS) through the formation of disulfide bonds, or selectively attach proteins with surface lysines (N-hydroxysunccinimide, NHS) through the formation of amide bonds. PEG monolayers that inhibit protein adsorption can also be formed from adsorption of siloxane polymer chains grafted with both methoxy-terminated ethylene gylcol and dialkyl disulfide side chains onto gold surfaces. The ability of the polymeric monolayers to specifically attach proteins with suface lysines was accomplished by replacing some of the methoxy-terminated PEG side chains with NHS-terminated PEG side chains.