Bioresponsive Targeted Charge Neutral Lipid Vesicles for Systemic Gene Delivery Protocol This protocol describes a stepwise procedure to prepare nucleic acids encapsulated in a polyethylene glycol (PEG)-shielded nanolipoparticle (NLP) that contain a bioresponsive lipid and ligand. This process provides several advantages for systemic gene delivery. The in vivo circulation time is extended. Also, low pH-sensitive lipids enhance DNA unpacking and endosomal escape. Finally, ligands inserted into the NLP surface can target gene delivery to specific tissues or cells in vivo.
Lipoplex and LPD Nanoparticles for In Vivo Gene Delivery Protocol Lipoplex (cationic liposome-DNA complex) is formed via electrostatic interaction of anionic nucleic acids with cationic liposomes. A thin film of lipids is dried on the bottom of a glass tube and rehydrated in an aqueous solution. The resulting liposome suspension is passed through polycarbonate filters of desired pore size. This protocol also describes the preparation, physical properties, and biological activity of liposome-polycation-DNA (LPD) nanoparticles.
PEI Nanoparticles for Targeted Gene Delivery Protocol This protocol describes the preparation of polyethylenimine (PEI)/DNA nanoparticles for targeted gene delivery. This delivery strategy improves the efficiency of gene transfer by enhancing the entry of gene vectors into the desired cells and reducing uptake by nontarget cells. We describe here methods for the conjugation of targeting peptides to PEIs, formation of DNA complexes using the conjugated PEIs or nonconjugated PEIs together with targeting peptides, and cell transfection.
