Vesicle transition of catanionic redox-switchable surfactants controlled by DNA with different chain lengths.

ABSTRACT

HYPOTHESIS: Electrostatic self-assembly is used as a facile and convenient method to fabricate soft materials with synergetic novel properties. The structural transition of building blocks could easily lead to the formation of assembly structures with various morphologies. Hence, the self-assembly behavior of DNA/surfactant vesicles could be driven by DNA base pair (bp) variation and the stimulated responsiveness of vesicles. EXPERIMENTS We report the bilayer transition of catanionic redox-switchable surfactant vesicles controlled by adding DNA with different chain lengths. Cryogenic transmission electron microscopy (cryo-TEM) was used to characterize the aggregation behavior of DNA and vesicles. FINDINGS: Cryo-TEM images revealed that short-chain inflexible DNA with 50 bp can act as anionic glue in the construction of catanionic bilayer vesicles to form tubular vesicles. Medium-long DNA of 250 bp adsorbs onto bilayer vesicles via electrostatic interactions to produce slightly thickened bilayer vesicles. Long-chain DNA with 2000 bp can be used as a building block to fabricate super-wall thickened (SWT) redox-responsive DNA bilayer vesicles with an average wall-thickness of 14.0 nm. The greater number of charges and more flexible of long-chain DNA may account for the construction of these SWT bilayer vesicles with high stability. In addition, the SWT DNA vesicles can even undergo structural rearrangement to generate over-sized bilayer vesicles by redox stimulation.