Formation and properties of a network gel formed from mixtures of diacetylenic and short-chain phosphocholine lipids.

A polymerizable gel superaggregate has been formed from low concentrations (6 mM) of phospholipid mixtures of polymerizable 1,2-bis(tricosa-10,12-diynoyl)-sn-glycero-3-phosphocholine and 1,2-bis(dinonoyl)-sn-glycero-3-phosphocholine. Transmission electron microscopy (TEM) revealed that the superaggregate structure consisted of a network of twisted, braided fibers and that the pore size of the gel ranged from 0.1 to 1.0 micron. TEM of gel plated with Ni revealed that the width of the fibers was 280 A. Optical microscopy demonstrated that the onset of the gel phase occurred at mole fraction 0.43 DNPC in the absence of salt and 0.36 in the presence of 0.25 M NaCl. Polymerization did not affect the morphology of the gel but did increase its temperature stability.