title: In vitro gene transfer efficacies of N,N-dialkylpyrrolidinium chlorides: a structure-activity investigation.
abstract: Inspired by the previously reported superior gene transfer efficacies of amine headgroup-containing cationic lipids to their hydroxy counterparts, in the present structure-activity investigation we have compared the relative in vitro gene transfer efficacies of eight newly synthesized structural analogues of our previously reported lipids 1-4, namely the four 3,4-diaminopyrrolidinium chloride structural analogues (lipids 9-12, Chart 1) and the N-BOC-protected precursors of these amine analogues (lipids 5-8, Chart 1) with our previously reported lipids 1-4 (Chart 1) in five cultured cell lines. In contrast to the above-mentioned earlier reports, except for the superior or comparable transfection efficacies of the diaminopyrrolidinium lipids with distearyl and stearyloleyl chains (lipid 11 and 12 respectively, Chart 1) in MCF-7 and HEK293T cells, the relative transfection efficacies of the other diamino analogues were found to be much lower than their dihydroxy counterparts. The results of the DNase I sensitivity assays indicate that enhanced degradation of DNA associated with lipids 9-12 by cellular DNase I might play an important role behind their seriously compromised transfection efficacies. In addition, the present structure-activity investigation revealed a strikingly cell tropic transfection behavior of lipid 6 (Chart 1). While lipids 5, 7, and 8 were found to be either poor or essentially incompetent in transfecting all the five cells, lipid 6 was remarkably efficacious in transfecting kidney cells (COS-1 and HEK293T cells) at lipid:DNA charge ratios 3:1 and 1:1 when used in combination with equimolar amounts of DOPE and DOPC.
authors.affiliation: Division of Lipid Science and Technology, Indian Institute of Chemical Technology, Hyderabad-500 007, India.
authors.forename: Bharat Kumar
authors.initials: BK
authors.lastname: Majeti
authors.forename: Priya Prakash
authors.initials: PP
authors.lastname: Karmali
authors.forename: B Surendar
authors.initials: BS
authors.lastname: Reddy
authors.forename: Arabinda
authors.initials: A
authors.lastname: Chaudhuri
mesh_terms: D000818:Animals; D002412:Cations; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002522:Chlorocebus aethiops; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000008:administration & dosage / Q000737:chemistry; D003850:Deoxyribonuclease I / Q000737:chemistry; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008055:Lipids / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D008081:Liposomes; D049329:Nanostructures; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014162:Transfection; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
chemical_list: D002412:Cations; D008055:Lipids; D008081:Liposomes; C501697:N,N-di-n-hexadecyl-3,4-di-tert-butyloxycarbonylaminopyrrolidinium; D011759:Pyrrolidines; D000644:Quaternary Ammonium Compounds; D004247:DNA; D003850:Deoxyribonuclease I; D001616:beta-Galactosidase