Structural Changes of DPPC Bilayers Induced by Gemini Surfactant

The phospholipid-gemini surfactant systems are promising agents for construction of lipoplexes for DNA delivery systems in gene therapy. In this work the influence of a gemini surfactant - 1,1'-(1,6-hexan)bis3-octyloxymethylimidazolium di-chloride) (IMI_Cl_C6_C8) on the structure and phase behaviour of aqueous suspensions of the fully hydrated phospholipid - 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) were characterised using small angle scattering of synchrotron radiation (SAXS), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The surfactant studied caused a destabilisation of the lamellar phase typical of DPPC. Addition of the surfactant also shifted to lower temperatures and extended the range of the main phase transition