SYNTHESIS AND HEMOCOMPATIBILITY EVALUATION OF NOVEL SEGMENTED POLYURETHANES WITH PHOSPHATIDYLCHOLINE POLAR HEADGROUPS

A new diol with a phosphatidylcholine polar headgroup, 2-hydroxymethyl )]propane-2-(trimethylammonio)ethyl phosphate (BTEP), was synthesized and characterized. The BTEP, together with 1,4-butanediol (BD) as a ch ain extender, was used to synthesize segmented polyurethanes (SPUs) ba sed on diphenylmethane diisocyanate (MDI) and various types of soft se gments such as polycarbonate, polyether, polyester, and hydrocarbon di ols. The bulk characteristics of the resulting SPUs were investigated by infrared (IR) spectroscopy, viscosity, and gel-permeation chromatog raphy (GPC) measurements. Good mechanical properties of the typical SP U containing poly(butadiene) glycol (PBD) were indicated by dynamic vi scoelasticity and tensile measurements, The phosphatidylcholine polar groups were oriented on the surface of these materials as revealed by attenuated total reflectance-Fourier transform infrared spectroscopy ( ATR-FTIR), electron spectroscopy for chemical analysis (ESCA), and con tact angle measurements. The hemocompatibilities of the new polymers w ere evaluated by platelet-rich plasma (PRP) contact studies and viewed by scanning electron microscopy (SEM) using medical BioSpan as a refe rence. The new materials have good surfaces in terms of platelet adhes ion, and the morphology of adhered platelets undergoes a relatively lo w degree of variation. Suitably increasing percentages of phosphatidyl choline polar groups in the polymers and higher molecular weights of t he soft segments of the polymers may further improve hemocompatibility .