title: Polyethylenimine nanoparticles as efficient transfecting agents for mammalian cells.
abstract: Two cross-linkers based on polyethylene glycol (PEG) (MW=6 and 8 kDa), were synthesized for self-assembling and formation of nanoparticles of branched, high molecular weight polyethylenimine (PEI). Cross-linking was realized in two ways, viz., ionic as well as covalent. Ionic cross-linking was accomplished by using PEG-bis (phosphate) whereas, the covalent one was achieved by using PEG-bis (p-nitrophenylcarbonate). A range of nanoparticles of PEI was prepared by varying the degree of cross-linking (i.e. the amount of cross-linkers used). PEI-PEG nanoparticles were characterized by dynamic light scattering and transmission electron microscopy and found to be in the range of approximately 18-75 nm (hydrodynamic radii) with almost uniform population. Subsequently, these particles were used for DNA binding assay and zeta-potential measurements, taking native PEI-PEG nanoparticles as reference. As expected, the zeta potential values decreased, on increasing the percentage of cross-linking as well as on complexation with DNA. Further, PEI-PEG nanoparticles were investigated for their transfecting efficacy on COS-1 cells. It was found that PEI-PEG nanoparticles were 5- to 16-fold more efficient as transfecting agents compared to lipofectin and PEI itself. The toxicity of PEI-PEG nanoparticles was found to be reduced considerably in comparison to PEI polymer, as determined by MTT colorimetric assay. Out of the various systems prepared, PEI-PEG8000 (5% ionic) nanoparticles were found to be the most efficient transfecting agent for in vitro transfection.
authors.affiliation: Nucleic Acids Research Laboratory and Division of Allergy and Infectious Diseases, Institute of Genomics and Integrative Biology, Mall Road, Delhi University Campus, Delhi - 110 007, India.
authors.forename: Surendra
authors.initials: S
authors.lastname: Nimesh
authors.affiliation: Nucleic Acids Research Laboratory and Division of Allergy and Infectious Diseases, Institute of Genomics and Integrative Biology, Mall Road, Delhi University Campus, Delhi - 110 007, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Goyal
authors.affiliation: Unilever Research Centre, Bangalore - 560 066, India.
authors.forename: Vikas
authors.initials: V
authors.lastname: Pawar
authors.affiliation: Unilever Research Centre, Bangalore - 560 066, India.
authors.forename: Sujatha
authors.initials: S
authors.lastname: Jayaraman
authors.affiliation: Nucleic Acids Research Laboratory and Division of Allergy and Infectious Diseases, Institute of Genomics and Integrative Biology, Mall Road, Delhi University Campus, Delhi - 110 007, India.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi - 110 007, India.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Chandra
authors.affiliation: Nucleic Acids Research Laboratory and Division of Allergy and Infectious Diseases, Institute of Genomics and Integrative Biology, Mall Road, Delhi University Campus, Delhi - 110 007, India.
authors.forename: Yogendra
authors.initials: Y
authors.lastname: Singh
authors.affiliation: Nucleic Acids Research Laboratory and Division of Allergy and Infectious Diseases, Institute of Genomics and Integrative Biology, Mall Road, Delhi University Campus, Delhi - 110 007, India. Electronic address: kcgupta@igib.res.in.
authors.forename: Kailash C
authors.initials: KC
authors.lastname: Gupta
mesh_terms: D000818:Animals; D019556:COS Cells; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003432:Cross-Linking Reagents; D004247:DNA / Q000008:administration & dosage / Q000737:chemistry; D004563:Electrochemistry; D004912:Erythrocytes / Q000187:drug effects; D005079:Excipients; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D046529:Microscopy, Electron, Transmission; D008970:Molecular Weight; D049329:Nanostructures; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011094:Polyethyleneimine / Q000737:chemistry*; D014162:Transfection / Q000379:methods*
chemical_list: D003432:Cross-Linking Reagents; D005079:Excipients; D010710:Phosphates; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D004247:DNA