Nanostructures and Activity of Polyelectrolyte/Surfactant Complexes

9984102Chu聚电解质凝胶与相反电荷的表面活性剂形成络合物的主要原因是静电和疏水相互作用。测定了聚电解质凝胶/表面活性剂络合物(PSCs)非常丰富的纳米结构。其中包括Pm3n空间群立方体、面心立方(FCC)、Ia3d空间群立方体、六方柱密堆积(HCPC)和六方球紧密堆积(HCPS)以及层状纳米结构，其中有几种是我们首次报道的。然而，关于自组装行为的微妙细节仍然缺乏。我们建议对pH、离子强度、共离子和反离子的性质以及聚电解质链长对络合物形成的影响进行选择性研究。更重要的是，PSC的形成动力学可以使我们创建半冻结结构。建议通过控制混合过程对PSC的形成动力学进行更定量的研究。阳离子表面活性剂将被用于与单链(和双链)DNA相互作用。单链DNA(或RNA)与相反电荷的生物表面活性剂(如脂质体、脂类或类脂)之间形成的络合物是将DNA(或RNA)运送到细胞的高效载体。这个想法是如何将遗传物质“包装”成一种非常紧凑的形式，以便跨细胞膜运输。这种复合体的形成可以将DNA体积减少约一千倍，从而克服了材料跨膜转移的障碍。我们知道，络合物的生物活性和由络合物形成的纳米结构可以关联。因此，我们的目标是确定能够控制DNA/表面活性物质复合体的大小和纳米结构的因素，然后将这些信息与用于基因传递目的的生物活性相关联。

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.