(206g) Vapor-Based Synthesis to Prepare Tri-Functional Coatings

One of the major challenges in current biomimetic modification technology is the control of multiple types of biomolecules on a surface. This study reports a novel tri-functional coating comprising distinguished anchoring sites of acetylene, maleimide, and ketone. The synthetic approach involves the chemical vapor deposition (CVD) copolymerization of 4-ethynyl-[2,2]paracyclophane, 4-N-maleimidomethyl-[2,2]paracyclophane, and trifluoroacetyl-[2.2]paracyclophane, and can be applied to various substrate materials. A surface analysis using X-ray photoelectron spectroscopy and infrared reflection absorption spectroscopy confirms that the chemical structure of the tri-functional coating is consistent with that of poly[(4-ethynyl-p-xylylene)-co-(4-N-maleimidomethyl-p-xylylene)-co-(trifluoroacetyl-p-xylylene)-co-(p-xylylene)]. The appropriate reactivity of the acetylene, maleimide, and ketone side groups is confirmed using the azide–alkyne click reaction, thiol-maleimide coupling, and hydrazide-ketone reaction with fluorescence-labeling molecules and biomolecules including azide-terminated polyethylene glycol (azide-PEG), sulfosuccinimidyl 6-(3'-[2-pyridyldithio]-propionamido) hexanoate (Sulfo-LC-SPDP), and biotinylated hydrazide. In addition, these tri-functional coatings can be fabricated in a microstructured fashion through a photolithographic process on non-conventional surfaces, such as a stent, giving a surface topologically defined and multifunctional sites for sophisticated biointerface engineering.