Enhancement of airway gene transfer by DNA nanoparticles using a pH-responsive block copolymer of polyethylene glycol and poly-l-lysine

Nicholas J. Boylan, Anthony J. Kim, Jung Soo Suk, Pichet Adstamongkonkul, Brian Simons, Samuel K. Lai, Mark J. Cooper, Justin Hanes

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


Highly compacted DNA nanoparticles, composed of single molecules of plasmid DNA compacted with block copolymers of polyethylene glycol and poly-l-lysine (PEG-CK 30), have shown considerable promise in human gene therapy clinical trials in the nares, but may be less capable of transfecting cells that lack surface nucleolin. To address this potential shortcoming, we formulated pH-responsive DNA nanoparticles that mediate gene transfer via a nucleolin-independent pathway. Poly-l-histidine was inserted between PEG and poly-l-lysine to form a triblock copolymer system, PEG-CH 12K 18. Inclusion of poly-l-histidine increased the buffering capacity of PEG-CH 12K 18 to levels comparable with branched polyethyleneimine. PEG-CH 12K 18 compacted DNA into rod-shaped DNA nanoparticles with similar morphology and colloidal stability as PEG-CK 30 DNA nanoparticles. PEG-CH 12K 18 DNA nanoparticles entered human bronchial epithelial cells (BEAS-2B) that lack surface nucleolin by a clathrin-dependent endocytic mechanism followed by endo-lysosomal processing. Despite trafficking through the degradative endo-lysosomal pathway, PEG-CH 12K 18 DNA nanoparticles improved the invitro gene transfer by ∼20-fold over PEG-CK 30 DNA nanoparticles, and invivo gene transfer to lung airways in BALB/c mice by~3-fold, while maintaining a favorable toxicity profile. These results represent an important step toward the rational development of an efficient gene delivery platform for the lungs based on highly compacted DNA nanoparticles.

Original languageEnglish (US)
Pages (from-to)2361-2371
Number of pages11
Issue number7
StatePublished - Mar 2012


  • Cystic fibrosis
  • Gene therapy
  • Non-viral
  • PH buffering

ASJC Scopus subject areas

  • Bioengineering
  • Ceramics and Composites
  • Biophysics
  • Biomaterials
  • Mechanics of Materials


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