Mucosal Vaccine Development Based on Liposome Technology

Figure 2

Generation of customized liposomes. Lipids are polar molecules consisting of a hydrophilic headgroup and hydrophobic fatty acid tails. Examples of positively charged headgroups are trimethylammonium propane (TAP) and dioctadecyl ammonium bromide (DA), while negatively charged headgroups are phosphatidylserine (PS), phosphatidylinositol (PI), phosphatidylglycerol (PG), or phosphatidic acid (PA), and finally neutral headgroups are phosphatidylcholine (PC) or phosphatidylethanolamine (PE). A headgroup can be combined with tails of different nature to create lipids with the desired properties; the examples shown are the lipid 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and the phospholipids dimyristoylphosphatidylglycerol (DMPG) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Different lipids can then be combined into liposomes with different functional features, which provide the basis for this highly diverse and versatile technology that is so excellently suited for vaccine development.