DNA gel nanoparticles: preparation and controlling the size

Abstract

A simple and novel method was used for the preparation of nano-/micro-sized DNA gel particles by nebulisation of a solution of DNA (single- or double-stranded) into an oppositely charged surfactant (cetyltrimethylammonium bromide) or protein (lysozyme, protamine sulfate) solution. The size and size distribution of the particle populations were investigated by means of fluorescence microscopy (FM), photon correlation spectroscopy (PCS) and scanning electron microscopy (SEM). Particles measuring from 0.1 to 10 µm were obtained. FM studies suggest that the formation of the particles was carried out with conservation of the secondary structure of the nucleic acid molecules. SEM on freeze-dried and Au-shadowed samples showed a distribution of virtually spherical particles. It was found that, in addition to the size of the initial DNA droplets, the cationic agent is a controlling parameter of the particle size.