Phospholipid-modified polyethylenimine-based nanopreparations for siRNA-mediated gene silencing: implications for transfection and the role of lipid components.
The clinical application of gene silencing mediated by small interfering RNA (siRNA) has been limited by the lack of efficient and safe carriers. Phospholipid modification of low molecular weight polyethylenimine (PEI 1.8 kDa) dramatically increased its gene down-regulation capacity while keeping cytotoxicity levels low. The silencing efficacy was highly dependent on the nature of the lipid grafted to PEI and the polymer/siRNA ratio employed. Phosphoethanolamine (DOPE and DPPE) and phosphocholine (PC) conjugation did not change the physicochemical properties and siRNA binding capacity of PEI complexes but had a large impact on their transfection and ability to down-regulate Green Fluorescent Protein (GFP) expression (60%, 30% and 5% decrease of GFP expression respectively). We found that the micelle-forming structure of DOPE and DPPE-PEI dramatically changed PEI's interaction with cell membranes and played a key role in promoting PEI 1.8 kDa transfection, completely ineffective in the absence of the lipid modification.


BACKGROUND
While siRNA-based gene silencing methods could have numerous clinical applications, efficient delivery remains a major challenge. This team reports that DOPE-PEI and DPPE-PEI based micelle-forming nanostructures may be able to provide an efficient vector for siRNA transfection.
Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA, USA.
Gemma
G
Navarro
Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA, USA.
Sean
S
Essex
Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA, USA.
Rupa R
RR
Sawant
Department of Pharmacy, Birla Institute of Technology and Sciences-Pilani., Hyderabad Campus Jawahar Nagar, Shameerpet Mandal. Hyderabad-500078. AP., India.
Swati
S
Biswas
Department of Pharmaceutics, JSS College of Pharmacy, JSS University S. S. Nagar, Mysore 570 015.
Dattatri
D
Nagesha
Electronic Materials Research Institute, Northeastern University, Boston, MA, USA.
Srinivas
S
Sridhar
Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, University of Navarra, Pamplona, Spain.
Conchita Tros
CT
de ILarduya
Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA, USA. Electronic address: v.torchilin@neu.edu.
Vladimir P
VP
Torchilin
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry; D004983:Ethanolamines / Q000737:chemistry; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D008055:Lipids / Q000737:chemistry*; D051379:Mice; D008823:Micelles; D008970:Molecular Weight; D050997:Nanomedicine; D053758:Nanoparticles / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D010767:Phosphorylcholine / Q000737:chemistry; D011094:Polyethyleneimine / Q000737:chemistry*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000737:chemistry
D004337:Drug Carriers; D004983:Ethanolamines; D008055:Lipids; D008823:Micelles; D010743:Phospholipids; D034741:RNA, Small Interfering; D010767:Phosphorylcholine; D049452:Green Fluorescent Proteins; C005448:phosphorylethanolamine; D011094:Polyethyleneimine
Lipid conjugation; Micelle; Phospholipid; Polyethylenimine; RNA interference; siRNA delivery