Novel fluorescent cationic phospholipid, O-4-napthylimido-1-butyl-DOPC, exhibits unusual foam morphology, forms hexagonal and cubic phases in mixtures, and transfects DNA

Rumiana Koynova, Howard S. Rosenzweig, Li Wang, Michael Wasielewski, Robert C. MacDonald

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7 Citations (Scopus)


The novel cationic triester of phosphatidylcholine, O-4-napthylimido-1- butyl-dioleoylphosphatidylcholine (NB-DOPC), has been synthesized: 1-amino-4-butanol was reacted with napthylic anhydride to form 4-hydroxybutyl-1-napthylamide, which was then reacted with triflic anhydride; the resultant triflate was reacted with dioleoylphosphatidylcholine so as to transfer the napthylimido-butyl group to the unsubstituted phosphate oxygen. The resultant compound is thus not only positively charged, but also has a bulky hydrophobic moiety attached to the headgroup. This novel cationic phospholipid exhibits a peculiar long-living foam-like morphology upon hydration, which could have applications in encapsulation and delivery. It is characterized by high adhesiveness to hydrophobic surfaces. X-ray diffraction showed that it forms a lamellar structure of rather short repeat period, indicative of an unusually small interlamellar separation and low hydration level. It readily incorporates DNA and organizes into lamellar lipoplexes. These DNA-lipid complexes effectively transfect DNA into cells. In an equimolar mixture of this lipid with the anionic dioleoylphosphatidylglycerol lamellar arrays coexist with disordered uncorrelated structures, however, these transform into a bicontinuous cubic phase, Pn3m, upon addition of DNA. When mixed with another anionic lipid, cardiolipin, at a NB-DOPC/ cardiolipin 2:1 molar ratio, it forms the inverted hexagonal phase which is of potential interest for nanotechnology applications.

Original languageEnglish
Pages (from-to)183-194
Number of pages12
JournalChemistry and Physics of Lipids
Issue number2
Publication statusPublished - May 1 2004



  • Cationic liposome
  • Cubic phase
  • Inverted hexagonal phase
  • Lipoplex
  • Transfection

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Organic Chemistry
  • Cell Biology

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