title: Small-Angle Neutron Scattering Studies on the Multilamellae Formed by Mixing Lamella-Forming Cationic Diblock Copolymers with Lipids and Their Interaction with DNA.
abstract: We demonstrate that the lamella-forming polystyrene-block-poly(N-methyl-4-vinylpyridinium iodine) (PS-b-P4VPQ), with similar sizes of the PS and P4VPQ blocks, can be dispersed in the aqueous solutions by forming lipid/PS-b-P4VPQ multilamellae. Using small-angle neutron scattering (SANS) and 1,2-dipalmitoyl-d62-sn-glycero-3-phosphocholine (d62-DPPC) in D2O, a broad correlation peak is found in the scattering profile that signifies the formation of the loosely ordered d62-DPPC/PS-b-P4VPQ multilamellae. The thicknesses of the hydrophobic and hydrophilic layers of the d62-DPPC/PS-b-P4VPQ multilamellae are close to the PS layer and the condensed brush layer thicknesses as determined from previous neutron reflectometry studies on the PS-b-P4VPQ monolayer at the air-water interface. Such well-dispersed d62-DPPC/PS-b-P4VPQ multilamellae are capable of forming multilamellae with DNA in aqueous solution. It is found that the encapsulation of DNA in the hydrophilic layer of the d62-DPPC/PS-b-P4VPQ multilamellae slightly increases the thickness of the hydrophilic layer. Adding CaCl2 can enhance the DNA adsorption in the hydrophilic brush layer, and it is similar to that observed in the neutron reflectometry study of the DNA adsorption by the PS-b-P4VPQ monolayer.
authors.affiliation: Department of Engineering and System Science, National Tsing Hua University , Hsinchu 300, Taiwan, Republic of China.
authors.forename: Po-Wei
authors.initials: PW
authors.lastname: Yang
authors.affiliation: Department of Engineering and System Science, National Tsing Hua University , Hsinchu 300, Taiwan, Republic of China.
authors.forename: Tsang-Lang
authors.initials: TL
authors.lastname: Lin
authors.affiliation: Department of Engineering and System Science, National Tsing Hua University , Hsinchu 300, Taiwan, Republic of China.
authors.forename: I-Ting
authors.initials: IT
authors.lastname: Liu
authors.affiliation: Department of Engineering and System Science, National Tsing Hua University , Hsinchu 300, Taiwan, Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Hu
authors.affiliation: National Synchrotron Radiation Research Center (NSRRC) , Hsinchu, 300, Taiwan, Republic of China.
authors.forename: U-Ser
authors.initials: US
authors.lastname: Jeng
authors.affiliation: Bragg Institute, Australian Nuclear Science and Technology Organisation (ANSTO) , Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia.
authors.forename: Elliot Paul
authors.initials: EP
authors.lastname: Gilbert
mesh_terms: D004247:DNA / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D033363:Neutron Diffraction; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry*; D053838:Scattering, Small Angle
chemical_list: D008055:Lipids; D011108:Polymers; D011137:Polystyrenes; D011726:Pyridinium Compounds; C000612156:polystyrene-block-poly(N-methyl-4-vinylpyridinium); D004247:DNA