Tuning lipid layer formation on particle surfaces by using DNA-containing recruiter molecules

Abstract

Biofunctional interfaces containing DNA-conjugated molecules have been explored for various bioengineering applications. However, there is still a lack of understanding of the interaction between DNA conjugates and surrounding biomolecules. In this study, we prepare DNA-containing recruiter molecules and incorporate them onto DNA immobilized gold nanoparticles through DNA hybridization. Liposomes composed of different phospholipids are then applied to investigate supported lipid layer formation on these recruiter-containing surfaces. We find that the morphology and the amount of lipid layers formed are determined by both the liposome concentration and the type of recruiter molecule. When liposomes are applied in excess above a critical concentration, surface chemistry determines the lipid layers formed, leading to lipid multilayers on hydrophilic DNA recruiter containing surfaces and lipid monolayers on hydrophobic DNA-lipid recruiter containing surfaces. When the liposome concentration is below the critical value, the surface molecules take on a more direct role and recruit lipids through hydrophobic interaction. The total amount of the lipid layers formed is further modulated by the overall charge and the fluidity of the liposomes applied. These results provide quantitative analysis on the interaction of DNA conjugates with lipid molecules and introduce a new approach to fine-tune lipid layer formation behavior.

Keywords: DNA-lipid conjugates; Gold nanoparticle; Lipid recruitment; Phospholipids; Supported lipid layer.