Methods and compositions useful for gene transfer into a salivary gland are provided. In certain aspects, methods and compositions useful in the treatment of hyposalivation and/or xerostomia are provided. In particular aspects, methods may include contacting a salivary gland of a subject with a composition containing microbubbles and a non-viral expression vector containing a nucleic acid sequence encoding a water channel, and applying ultrasound to the salivary gland.
