Phospholipid polymers

This review compiles the literature on phospholipid polymers from 1974 to 1997. A variety of approaches for phospholipid analogous polymers such as polymeric vinyl phosphatidylcholine and phosphatidylethanolamine analogues, the polymers with cholesterol moieties and polymeric glycolipid analogues have been described. As the predominant phospholipids are phosphatidylcholine, attention in this review is mainly focused on the development of phosphatidylcholine analogous polymers. Synthesis of vinyl phospholipid polymers, phospholipid modified polypeptides, phospholipid organosiloxanes, and phospholipid polyurethanes are described. Several ring-opening reagents such as trimethylamine, 2-dimethylaminoethyl methacrylate, and 6-dimethylaminohexylmethacrylate for side chain types of vinyl phospholipid polymers, and some ring-opening reagents such as N, N, N', N'-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl)stearylamine, aza-crown ether, and thermal polymerization for main chain types of phospholipid polymers, are discussed. A general reaction route to synthesize phospholipid polymers and a reaction scheme to prepare phospholipid diols are summarized. Characterization techniques for phospholipid polymers are also described. These include infrared spectroscopy, viscosity, and gel permeation chromatography measurements for bulk property; X-ray diffraction methods fur structure, dynamic viscoelasticity and tensile measurements fur mechanical properties. Moreover, the pi-A isotherms and LB multilayers, electron microscopy with diffraction and dark-field techniques, attenuated total reflectance-Fourier transform infrared spectroscopy, electron spectroscopy for chemical analysis, and contact angle measurements for surface properties; platelet-rich plasma contact studies and scanning electron microscopy observation for blood compatibilities, are all described. Properties such as liquid crystalline behavior, polyelectrolyte viscosity behavior, hygroscopic characteristic, and blood compatibility and their potential applications are discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.