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Genospheres: self-assembling nucleic acid-lipid nanoparticles suitable for targeted gene delivery


We describe the assembly of a cationic lipid-nucleic acid nanoparticle from a liquid monophase containing water and a water miscible organic solvent where both lipid and DNA components are separately soluble prior to their combination. Upon removal of the organic solvent, stable and homogenously sized (70–100 nm) lipid-nucleic acid nanoparticles (Genospheres™) were formed. The low accessibility (<15%) of the nanoparticle-encapsulated DNA to a DNA intercalating dye indicated well-protected nucleic acids and high DNA incorporation efficiencies. It was demonstrated that Genospheres could be stably stored under a variety of conditions including a lyophilized state where no appreciable increase in particle size or DNA accessibility was observed following reconstitution. Finally, Genospheres were made target-specific by insertion of an antibody-lipopolymer (anti-HER2 scFv (F5)-PEG-DSPE) conjugate into the particle. The target specificity (>100-fold) in HER2 overexpressing SK-BR-3 breast cancer cells was dependent on the degree of PEGylation, where the incorporation of high amounts of PEG-lipid on the particle surface (up to 5 mol%) had only a minor effect on the transfection activity of the targeted Genospheres. In summary, this work describes a novel, readily scalable method for preparing highly stable immunotargeted nucleic acid delivery vehicles capable of achieving a high degree of specific transfection activity.

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We thank Drs Joel Cohen and Valentina Khorosheva of the University of the Pacific, San Francisco for the zeta potential measurements. We also would like to thank Dr Brigitte Papahadjopoulos-Sternberg for performing the FFEM.

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Correspondence to K Hong.

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Hayes, M., Drummond, D., Kirpotin, D. et al. Genospheres: self-assembling nucleic acid-lipid nanoparticles suitable for targeted gene delivery. Gene Ther 13, 646–651 (2006).

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  • nonviral gene delivery
  • plasmid encapsulation
  • targeted gene delivery
  • HER2 receptor

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