Custom designed microbubble contrast agents and techniques of ultrasound delivery optimized for gene therapy

Abstract

The invention pertains to a lipid-based microbubble stably binding a plurality of nucleic acids, and a method of delivering the microbubble and nucleic acids to a specific target site using ultrasound. The delivered nucleic acids create transgenic cells (i.e., for example, a transgenic tumor cell), wherein the transgenic cell expresses the proteins encoded by the delivered nucleic acids. This technology provides a significant improvement for microbubble-drug delivery platforms as known microbubble do not efficiently bind nucleic acids. The improvements described herein include but are not limited to identifying proper lipid proportionality ratios and/or cationic surfactant layers that provide an optimum mechanical index compatible with ultrasonics. Microbubble perfusion and/or nucleic acid delivery may be performed by a combination of imaging and ultrasound/microbubble targeted delivery to simultaneously perform low power two-dimensional imaging and high power microbubble destruction. Such systems are useful in therapeutics and/or diagnostics. For example, the data disclosed herein shows proof of principle in conjunction with the delivery of therapeutic siRNA molecules to slow tumor growth.