Incorporation of Natural Lipids into Polymerizable Membranes

1 Incorporation of Natural Lipids into Polymerizable Membranes 

What reasons are there for mixing polymerizable lipids with natural ones Polymerized membrane systems, especially those based on diacetylenic lipids, have proven to be excessively rigid and to show no phase transition. Addition of natural lipids could help to retain a certain membrane mobility even in the polymerized state, with almost unaffected stability. Furthermore, natural lipids can provide a suitable environment for the incorporation of membrane proteins into polymerizable membranes (see 4.2.3). Besides this, enzymatic hydrolysis of the natural membrane component can be used for selectively opening up a vesicle in order to release entrapped substances in a defined manner (see 4.2.2). Therefore, it is interesting to learn about the miscibility of polymerizable and natural lipids and also about the polymerization behavior of these mixtures. Investigations on this subject have thus far focused on mixtures of natural lipids with polymerizable lipids carrying diacetylene moieties. 

Their phase and polymerization behavior were characterized in monolayers and vesicles 62). 

In general, the miscibility of two lipid components is influenced by different factors  

The cationic lipid (20, n = 12), the natural lipid (23) and the zwitterionic diacetylenic lecithin (18, n = 12) were mixed with naturally occurring lecithins, cephalins, and cholesterol. 

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