title: Interaction of photosensitive surfactant with DNA and poly acrylic acid.
abstract: In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes' properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate - for the first time - complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules.
authors: Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors: Yuriy
authors: Y
authors: Zakrevskyy
authors: Physical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors: Piotr
authors: P
authors: Cywinski
authors: Physical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors: Magdalena
authors: M
authors: Cywinska
authors: Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors: Jens
authors: J
authors: Paasche
authors: Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors: Nino
authors: N
authors: Lomadze
authors: Physical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors: Oliver
authors: O
authors: Reich
authors: Physical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors: Hans-Gerd
authors: HG
authors: Löhmannsröben
authors: Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
authors: Svetlana
authors: S
authors: Santer
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D001391:Azo Compounds / Q000737:chemistry; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D057446:Hydrodynamics; D057927:Hydrophobic and Hydrophilic Interactions; D007536:Isomerism; D008956:Models, Chemical; D013501:Surface-Active Agents / Q000737:chemistry*; D013950:Thymus Gland; D014466:Ultraviolet Rays
chemical_list: D000180:Acrylic Resins; D001391:Azo Compounds; D013501:Surface-Active Agents; C006903:carbopol 940; D004247:DNA; C009850:azobenzene