UC San Diego

In vivo systemic gene therapy approaches remain largely limited by short circulation time of genetic vectors and poor target specificity with techniques made to address one concern usually leading to a tradeoff for the other. This dissertation explores the use of nanoparticle delivery vehicles to overcome the above two constraints for both non-viral and viral vectors for gene therapy. In chapter two, we demonstrate an ultrasound sensitized liposomal gene delivery vehicle that can be activated using clinically relevant focused ultrasound. We were able to trigger a 7 fold increase in gene transfection as measured via a luciferase reporter system by exposing the liposomes to focused ultrasound. In chapter three, we explored a novel coating method for viral vectors that retains viral activity while shielding the coated viruses from immune neutralization. Using this technique we were able to achieve viral transfection in passively immunized mice with our coated viruses in contrast to bare viruses. In chapter four, we demonstrated the ability to induce ultrasound triggered release of viral particles by introducing an ultrasound sensitizing agent in the form of a perfluorocarbon nanoemulsion into our coated viral nanoparticles. These ultrasound sensitized viral nanoparticles remain in an inactive state till triggered by ultrasound upon which they regain infectious capability. Released viral particles retain protection against neutralizing antibodies and can be precisely targeted using ultrasound