Preparation of hydrocarbon/fluorocarbon double-chain phospholipid polymer brusheson polyurethane films by ATRP.

To fabricate artificial biomembrane mimicking cell surfaces, hydrocarbon/fluorocarbon double-chain phospholipid macromonomer was grafted on polyurethane (PU) film surfaces by surface-initiated atom transfer radical polymerization (SI-ATRP). The surface structures of modified PU film surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and water contact angle measurement. The results indicate that initiator densities on these polymer film surfaces have a significant impact on graft polymerization of this fluorocarbon phospholipid macromonomer. The phospholipid polymer brushes grafted on PU film surfaces could self-assemble into biomimetic membranes under water environment, as demonstrated by liquid/liquid static contact angle measurement, atomic force spectroscopy (AFM), and attenuated total reflectance Fourier transform infrared (ATR-FTIR). These biomimetic membranes could maintain water within them as the "surrounding" water. Such would be favorable condition for the preservation of native conformational state of proteins and cell membranes. This work provides a new approach to fabricate biomimetic membranes on biomaterials surfaces.