Compactness of Plasmid DNA in complexation with Urethane Cationic Gemini Surfactants

Gemini surfactants are a series of surfactants composed of two hydrophobic chains and two polar head groups linked by a spacer. They have lower CMC and krafft point values, higher solubilization power, better wetting and foaming abilities compared with conventional surfactants. Gemini surfactants can be categorized into different sub-classes depending on the variation of three structural elements i.e. hydrocarbon chains, head groups and the spacer . These surfactants have different applications in industries, such as synthesis of mesoporous materials, electrode surface modification in electrochemistry and so on. In addition, some research has been conducted on the use of these gemini surfactants as gene and/or drug carriers .In this research, nanoparticles are synthesized from cationic gemini surfactants having 6 methylene group (C6) as a spacer. The binding of these surfactants with plasmid DNA (pDNA) is studied in various surfactant to pDNA molar ratios. Gel retardation assay is used to confirm the formation of pDNA-gemini surfactant complexes. Results indicate that gemini surfactants neutralize the negative charge of pDNA even at low concentrations. Furthermore, stable complexes are formed at higher concentrations of surfactants which cause complete retardation in gel electrophoresis. In other words, these gemini surfactants are able to compact the pDNA and then can be considered as effective pDNA nano-carriers.

Keywords:

Gemini surfactant , DNA binding , pDNA nano-carrier , Charge neutralization