researchers in Japan have used the established electrospray (ES) process (from mass spectrometry) to deliver DNA into living cells.
It kind of makes sense, as mass spectrometrists have spent more than a decade turning ES into the gentlest method of transferring biomolecules from solution to the gas phase and firing them at a target, so nowadays they can do miracles with that method, spraying very sensitive assemblies and all kinds of things.
So using this for gene delivery as well looks like a very promising idea to me. And it will be important once gene therapy takes off.
Source: Angewandte Chemie online - DOI: 10.1002/anie.200704429