SMOOTH AND HOMOGENEOUS PEG-FUNCTIONALIZED POLYSILOXANES FOR PROTEIN REPELLENCY
Date
2015-06-12
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Abstract
Polydimethylsiloxanes (PDMS) are important organosilicone compounds that offer a wide range of biological and biomedical applications due to their unique structural properties. However, their inherently hydrophobic surface renders them incompatible with biological systems. Hydrophobic surfaces typically adsorb proteins, which leads to undesirable consequences such as biofilm formation and consequent microbial contamination.
The goal of this study was to create a biocompatible platform by modifying the surfaces of PDMS based substrates. Thiol-functionalized substrates were fabricated by reacting silicon wafers with thiol-functionalized PDMS. Unfortunately, the thiol layers as prepared were rough and non-uniform due to disulfide bond formation between reagent molecules. Reducing agents, such as dithiothreitol, applied during the modification reaction, were necessary to generate smooth and uniform thiol layers. The thiol-functionalized substrates were subsequently evaluated as platforms for conjugations of molecules of biological interest. Vinyl-terminated poly(ethylene glycol) of varying molecular weights were “clicked” to the substrates via thiol-ene photochemistry to hydrophilize the surfaces and hence minimize non-specific protein adsorption. The substrates were characterized using ellipsometry, contact angle goniometry, and atomic force microscopy before and after each reaction.
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PDMS, hydrophobicity, hydrophilicity, biocompatible, reducing agent, PEG, surface modification, DTT