title: Non-covalent functionalization of single-walled carbon nanotubes with modified polyethyleneimines for efficient gene delivery.
abstract: Functionalized carbon nanotubes (CNTs) have been recently emerged as important class of vectors for delivery of DNA and other biomolecules into various cells. In this study, single-walled carbon nanotubes (SWNTs) were functionalized by non-covalent binding of hydrophobic moieties, which were covalently linked to polyethyleneimines (PEIs). PEIs of three molecular weights (25, 10 and 1.8kDa) were used. CNTs were functionalized with the PEI series either through phospholipid moiety (via a polyethyleneglycol linker) or through directly-attached long (18 carbons) or intermediate (10 carbons) hydrophobic alkyl moieties. All PEI-functionalized CNTs exhibited good stability and dispersibility in biological media. Visualizing of functionalized CNTs and lack of aggregation were confirmed by atomic force microscopy. The PEI derivatives bound to CNTs retained the ability to fully condense plasmid DNA at low N/P ratios and substantial buffering capacity in the endosomal pH range. PEI-functionalized CNTs exhibited increased transfection efficiency compared to underivatized PEIs up to 19-fold increase being observed in the functionalized CNT with the smallest PEI tested, the smallest hydrophobic attachment moiety tested and no linker. Also PEI-functionalized CNTs were effective gene delivery vectors in vivo following tail vein injection in mice with the largest expression occurring with the vector PEI-functionalized through a polyethyleneglycol linker.
authors.affiliation: Pharmaceutical Reseach Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Behzad
authors.initials: B
authors.lastname: Behnam
authors.forename: Wayne T
authors.initials: WT
authors.lastname: Shier
authors.forename: Azadeh Hashem
authors.initials: AH
authors.lastname: Nia
authors.forename: Khalil
authors.initials: K
authors.lastname: Abnous
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ramezani
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D007275:Injections, Intravenous; D051379:Mice; D008807:Mice, Inbred BALB C; D018625:Microscopy, Atomic Force; D008970:Molecular Weight; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity; D009690:Nucleic Acid Conformation; D010743:Phospholipids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011094:Polyethyleneimine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D014162:Transfection / Q000379:methods*
chemical_list: D037742:Nanotubes, Carbon; D010743:Phospholipids; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D004247:DNA
keywords: Gene delivery; In vivo; Non-viral vector; Polyethyleneimine; Single-walled carbon nanotubes