Needle electrodes for mediated delivery of drugs and genes

An electrode apparatus for the application of electric fields to a selected portion of a living body, comprising:

• support means;
• an array of electrodes mounted on said support means in spaced relation to one another, at least a plurality of said electrodes having a needle configuration for penetrating tissue for in vivo electroporation of cells of the tissue;
• and
• an electric pulse generator for applying pulses of high amplitude electric signals to the electrodes proportionate to the distance between said electrodes for electroporation of cells between said electrodes, wherein said array of electrodes comprises a circular array of needle electrodes, and a switch assembly for selectively changing the polarity of opposing ones of said electrodes.

A needle electrode assembly of needle electrodes for the application of electric fields to a selected portion of a living body, comprising:

• a first combination needle electrode for insertion into selected tissue for injecting molecules into said tissue and for functioning as a first electrode;
• a second combination of multiple needle electrodes for insertion into said selected tissue spaced from said first electrode, at least one of said multiple electrodes functioning as a second electrode in relation to said first electrode;
• and
• means for selectively connecting multiple pairs of said needle electrodes in pairs of opposed polarity to an electric pulse generator for applying pulses of high amplitude electric signals to the electrodes proportionate to the distance between said electrodes for in vivo electroporation of cells between said electrodes.