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Analysis of immobilized L ‐cysteine on polymers
Author(s) -
GappaFahlenkamp H.,
Duan X.,
Lewis R. S.
Publication year - 2004
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.30180
Subject(s) - cysteine , chemiluminescence , thiol , polymer , materials science , x ray photoelectron spectroscopy , detection limit , combinatorial chemistry , chemical engineering , nuclear chemistry , polymer chemistry , chemistry , chromatography , biochemistry , enzyme , engineering , composite material
Recently, we reported that L ‐cysteine attached to polymeric biomaterials, without prior nitrosation, enhances the hemocompatibility of biomaterials via exploiting endogenous nitric oxide (NO). As part of the polymer optimization process to further enhance platelet inhibition, a kinetic model is being developed to predict the release rate of NO. A key model parameter is the immobilized concentration of L ‐cysteine. This article demonstrates how several chemiluminescence‐based assays, previously utilized for measuring thiols in solution, were successfully adapted to quantify immobilized L ‐cysteine. The assays showed that the immobilized L ‐cysteine on the modified PET sample is within the range of 4.1 to 6.5 nmol/cm 2 . An advantage of using the more successful chemiluminescence‐based assay is that it can accurately measure molar concentrations of any thiol‐containing compound with a detection limit in the pmol range. The major disadvantage is that L ‐cysteine must first be broken off of the polymer and released into solution prior to measurement, therefore leaving the sample unable to be reused. Other thiol‐measuring techniques, such as fluorescence microscopy and X‐ray photoelectron spectroscopy (XPS), were used to provide qualitative and semiquantitative analysis to substantiate the polymer development. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 519–527, 2004