A method for encapsulating nucleic acids, particularly siRNAs, shRNAs, microRNAs, gene therapy plasmids, and other oligonucleotides in biodegradable polymers is disclosed, whereby the nucleic acids are formulated into reverse micelles composed of non-toxic and/or naturally-occurring lipids prior to nanoparticle formation by nanoprecipitation. This method can be coupled to other techniques that improve intracellular drug targeting, ultimately enhancing intracellular delivery of the aforementioned nucleic acids.