Journal of Polymer Science Part A: Polymer Chemistry, Vol.55, No.10, 1742-1749, 2017
Stimuli-responsive antifouling polyisobutylene-based biomaterials via modular surface functionalization
This article demonstrates a new, modular approach to surface functionalization that harnesses chain entanglement. A layer of functionalized polyisobutylene, (PIB)-omega, where omega=-OH, -thymine (T), -hexaethylene glycol (HEG), poly(ethylene glycol) (-PEG-OH), methoxy-functionalized poly(ethylene glycol) (-PEG-OCH3), and -tetraethylene glycol-alpha-lipoate (TEG-alpha L) was adhered to PIB-based thermoplastic elastomer (TPE) surfaces. X-ray photoelectron spectroscopy (XPS) at angles ranging from 20 degrees to 75 degrees showed decreasing polar group concentration with increasing penetration depth, confirming segregation of polar groups toward the surface. Water contact angle (WCA) of the PIB-based TPE dropped from 95 degrees to 79 degrees-83 degrees upon coating, and soaking in water for 24 h further decreased the WCA. Dynamic WCA measurements showed 40-30 degrees receding angles, showing that stimulus from an aqueous environment elicits enrichment of polar groups on the surface. Fibrinogen (Fg) adsorption on the various surfaces was quantified using surface plasmon resonance (SPR). Static and dynamic WCA did not vary significantly among TPE+PIB-omega surfaces, but there were dramatic differences in Fg adsorption: 256 ng/cm(2) was measured on the native TPE, which dropped to 40 and 22 ng/cm(2) on PIB-PEG-OCH3 and PIB-PEG-OH-coated surfaces. PIB-TEG-L-coated surfaces presented the lowest Fg adsorption with 14 ng/cm(2). (C) 2017 Wiley Periodicals, Inc.