Neutralized Nanoparticle Composed of SS‐Cleavable and pH‐Activated Lipid‐Like Material as a Long‐Lasting and Liver‐Specific Gene Delivery System

Charge-neutralized lipid envelope-type nanoparticles formed with SS-cleavable and pH-activated lipid-like materials (ssPalm) accumulate rapidly in the liver without forming aggregates in the blood circulation, and result in a liver-specific gene expression for a long duration (>2 weeks) with neither immunological responses nor hepatotoxicity after intraveneous administration, when it carries pDNA free from CpG-motifs.