Simulation of self-assembly behaviour of fluorinated phospholipid molecules in aqueous solution by dissipative particle dynamics method

Abstract

In order to prepare novel biomaterials, it is essential to investigate the self-assembly behaviour of molecules containing both hydrophobic and hydrophilic groups, and to understand their structural change and morphological development. In this paper, we studied the self-assembly behaviour of fluorinated double-chain phospholipid molecules in aqueous solution at various simulation steps, concentrations, temperatures and pH values via the dissipative particle dynamics simulation method. The self-assembly behaviours of hydrogenated analogues and fluorinated single-chain phospholipids at various concentrations were also investigated for comparison. It was found that all molecules could form microsphere at low concentration, and aggregated to form various shapes with the increase of concentration. Fluorinated double-chain phospholipids were apt to form bilayer membrane more easily than hydrogenated/fluorinated single-chain phospholipids. Besides concentration, temperature and pH value of the aqueous solution also influence the self-assembly behaviour of the investigated molecules. A stable bilayer membrane could be achieved for the fluorinated double-chain phospholipids at a relatively high concentration when pH value and temperature of aqueous solution were close to physiological conditions, i.e., pH 7 and T = 37°C. This work provides a direct ‘observation’ of self-assembly behaviour in the molecular level, which is important for the development of novel biomaterials, where surface structure is required to be well controlled.