Analysis of albumin deposits on hydroxylated siloxane films. Implications for surface treatment of medical devices.
The authors have developed methods to enhance albumin binding to modified silicone rubber (SR) films. An intermediate bifunctional coupling agent, polyvinylmethyl siloxane-comethyl-1-ethanol siloxane (PVMS-CO-MES), is prepared from a cyclic tetramer, vinyl-methyl siloxane, by an oxymercuration-demercuration reaction, and cross-linked to silicone rubber under mild peroxide catalytic conditions. Free mercury on the surface was obtained under many reaction conditions and is shown to materially enhance 125I-labeled albumin binding. The mechanism most likely occurs via disulfide bond breakage, protein denaturation, and aggregation. The possible role of iodine-mercury bonds, an artefactual source, is ruled out with the aid of total internal reflectance-fluorescence measurements of the albumin adsorption rate constant. Although in situ albumin aggregation via disulfide bond breakage is a potentially attractive method for biocompatible protein gel formation, the toxicity of mercury makes the current method unfit for clinical practice.
Nelson
K D
KD
Biomedical Engineering Program, University of Texas Southwestern Medical Center at Dallas 75235-9031.
Tsai
C C
CC
Kulik
E A
EA
Sevastianov
V I
VI
Constantinescu
A
A
Eberhart
R C
RC
D000327:Adsorption; D004864:Equipment and Supplies; D006801:Humans; D012709:Serum Albumin; D012711:Serum Albumin, Radio-Iodinated; D012833:Siloxanes; D013499:Surface Properties
D012709:Serum Albumin; D012711:Serum Albumin, Radio-Iodinated; D012833:Siloxanes