Development, synthesis, and testing of novel polyacridine peptide gene carriers: advancements in liver targeting and endosomal escape

Various liver diseases can arise from changes in the deoxyribonucleic acid or DNA sequence, and one way to treat or cure them is through gene therapy by delivering correct DNA copies to the affected liver cells. DNA is notoriously unstable outside of the cell, however, requiring encapsulation into protective nanoparticles that can survive in the body. Additionally, these DNA nanoparticles must target to and get inside of the proper cell.

Previously, we’ve developed peptide or small protein-based nanoparticles that protect DNA but are unable to intrinsically deliver it to the interior of liver cells. This thesis work attempts to improve these nanoparticles by incorporating additional components for targeted DNA delivery. These components include proteins or small sugar molecules capable of specifically binding to the liver cell membrane, as well as isolated compounds from bee venom that allow nanoparticles to cross cell membranes by forming holes. Initial testing of these components with isolated cells identified several proteins that could bind liver cells, but also revealed that DNA delivery was still inefficient.

Optimization of the identity and organization of these components in the nanoparticles resulted in advanced systems that could not only deliver DNA to isolated liver cells, but also specifically localize to the liver in mice. This work thus not only advances our current knowledge on developing multifunctional synthetic nanoparticles, but also identifies a DNA delivery system that can be further tuned for liver gene therapy.