Oligonucleotide On The Micelle To Vesicle Transformation Role In Promoting Research

The formation and influence factor of oligonucleotide/sodium dodecyl sulfate (SDS)/dodecyl triethyl ammonium bromide (DEAB) vesicles are studied by dynamic light scattering, negative staining-TEM, CD, fluorescent microscopy, Zeta potential, UV-vis spectroscopy, 1H NMR and turbidity measurements. The results show that oligonucleotide could induce SDS/DEAB mixed micelles to transform to vesicles at lower temperature, and there are more SDS molecules than DEAB molecules in the vesicles, so the vesicles are negatively charged. The hydrophobic interaction between oligonucleotide and SDS/DEAB mixed micelles is the main driving force for the formation of oligonucleotide/SDS/DEAB vesicles. The facilitation efficiency of oligonucleotide which is composed of the same base on vesicle formation is closely dependent on its size and base structure. However, the oligonucleotide with a hairpin structure plays a different role in promoting the transformation from SDS/DEAB mixed micelles to vesicles; the facilitation efficiency for oligo d(AnCTn) is independent on the base number, whereas the facilitation efficiency for oligo d(AT)nACT(AT)n is reduced with the increase of the base number.According to the experimental results of dynamic light scattering, negative staining-TEM, CD, fluorescent microscopy, Zeta potential and turbidity measurements, the formation of oligonucleotide/SDS/DEAB vesicles is also affected by the pH value. Hydroxide is beneficial to the formation of hairpin-like oligonucleotide /SDS/DEAB vesicles. However, it has negative effect on the formation of oligonucleotide (composed of the same base)/SDS/DEAB vesicles.A further investigation indicates that oligonucleotide could induce single-chained cationic surfactant molecules to aggregate into vesicles. It is easier to form oligonucleotide/cationic surfactant vesicles when the oligonucleotide chain is longer or the electron deficiency of base is stronger. The hydrophobic chain length of cationic surfactant also affects vesicle formation; longer the hydrophobic chain, more difficult for vesicle to form. The hydrophobic and electrostatic interaction between oligonucleotide and cationic surfactant are the driving forces for vesicle formation.