Patent ID: 7811603

Claim:
A method of forming monodisperse lipoplex assemblies, said lipoplex assemblies comprising a complex formed between a cationic lipid and a nucleic acid, the method comprising: providing a microfluidic device having a main channel including a droplet generation zone, the droplet generation zone comprising an intersection between the main channel and a first and a second carrier channels configured to receive a hydrophobic fluid, the microfluidic device further comprising a first and a second inlet channels coupled to the main channel at a region upstream from the droplet generation zone; providing a first reactant in fluid communication with the first inlet channel, the first reactant comprising a cationic lipid; providing a second reactant in fluid communication with the second inlet channel, the second reactant comprising a nucleic acid; providing a hydrophobic fluid in fluid communication with the first and second carrier channels; flowing the first and second reactants and the hydrophobic fluid into the droplet generation zone to form aqueous droplets; mixing the aqueous droplets containing the cationic lipid and the nucleic acid by passing the same in a single direction through a mixing region downstream of the droplet generation zone, the mixing region comprising a sawtooth-shaped channel configured to induce convective flow inside the droplets, wherein said mixing generates a plurality of aqueous droplets containing a plurality of monodisperse lipoplex assemblies; and splitting the generated aqueous droplets into a plurality of smaller sized aqueous droplets containing plurality of monodisperse lipoplex assemblies having substantially the same number of cationic lipid and nucleic acid molecules in a single droplet that is generally electrically neutral.