Modular Surface Functionalization Of Polyisobutylene-Based Thermoplastic Elastomers

The Puskas group proposed to modify the surface properties of polyisobutylene (PIB)-based thermoplastic elastomers (TPEs) using a modular approach. PIB-based TPEs are emerging biomaterials; the first generation is used as the drug-eluting coating on coronary stents.  The surface chemistry of PIB-based TPEs can be modified using this modular approach by “gluing” low molecular weight functionalized PIBs (PIB-X) to the surface of the TPEs. PIB-OH was made by living carbocationic polymerization using propylene oxide as initiator and titanium tetrachloride (TiCl₄) as coinitiator. PIB-PEG was then synthesized from PIB-OH using Candida Antartica Lipase B (CALB) as catalyst and spin coated onto the surface of a TPE. Protein adsorption studies using Surface Plasmon Resonance (SPR) demonstrated decreased fibrinogen adsorption to the modified surface. This modular approach is much simpler than attaching functional groups covalently to surfaces, therefore it holds great promise in practical applications.