Nanostructures and Activity of Polyelectrolyte/Surfactant Complexes

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9984102ChuThe complex formation of polyelectrolyte gels with oppositely charge surfactants is driven mainly by electrostatic and hydrophobic interactions. Very rich nanostructures of the polyelectrolyte gel/surfactant complexes (PSCs) have been determined. These include Pm3n space group cubic, face-centered cubic (FCC), Ia3d space group cubic, hexagonal close packing of cylinders (HCPC) and hexagonal close packing of spheres (HCPS) as well as lamella nanostructures, with several of them being reported by us for the first time. The subtle details on the self-assembly behavior are, however, lacking. We propose to make selected studies on the effects of pH, ionic strength, nature of co-ion and of counter ion, and the polyelectrolyte chain length on complex formation. More importantly, the kinetics of PSC formation could permit us to create semi-frozen structures. It is proposed to undertake a more quantitative investigation on the kinetics of PSC formation by controlling the mixing process.Cationic surfactants will be used to interact with single-stranded (and double-stranded) DNAs. Complexes formed between ssDNA (or RNA) and oppositely charged biological surfactants, such as liposomes, lipids or lipitoids, represent a highly efficient vehicle for deliver of DNAS (or RNAs) to cells. The idea is how the genetic material can be "packaged" into a very compact form for transport across cell membranes. The complex formation can reduce the DNA volume by about a thousand fold and thereby overcome the barrier for a transfer of the material across membranes. We know that the biological activity of the complex and the nanostructures formed by the complexes can be correlated. Therefore, our objective is to determine the factors that can control the size and the nanostructures of DNA/surfactant complexes and then to correlate this information wit biological activity for gene delivery purposes.