title: Characterization of reducible peptide oligomers as carriers for gene delivery.
abstract: The stability of DNA-polyplexes and intracellular DNA release are important features of gene delivery systems. To study these features, we have evaluated reducible cysteine-flanked linear lysine and arginine-rich peptides, modified with histidine residues. The reducible disulfide bonds in cysteine flanked peptides and histidine residues should augment DNA release from the peptide-DNA complexes upon disintegration of the reducible bonds. Template polymerization and oxidative polycondensation were applied to obtain peptide oligomers used for DNA-polyplex preparation. The peptides and DNA-peptide complexes were investigated with physical, chemical and transfection measurements. Physicochemical and transfection properties of DNA-polyplexes depended on the amino acid sequence of the peptidic polymers and type of the polymerization. MALDI-TOF analysis of oxidatively polycondensed products revealed several forms of peptide oligomers corresponding to 5-8 amino acid monomers. DNA-peptide particles based on template-polymerized complexes were more resistant to relaxation by negatively charged heparan sulfate than polyplexes formed with oxidatively condensed peptides. Complexes of DNA with the polycations prepared by oxidative polycondensation exhibited a 100-1000-fold higher level of gene expression compared to DNA/template-polymerized peptide complexes. The most efficient transgene expression was shown with arginine-rich polyplexes. Transfection efficacy of the arginine-rich polyplexes was even 10-fold better than that of DNA/PEI complexes. On average, polyplexes based on cysteine-flanked peptide oligomers showed lower cytotoxicity than non-reducible high molecular weight polylysine/DNA particles. We conclude that reducible peptide oligomers provide efficient DNA transfection and have the potential as vehicles for gene delivery.
authors.affiliation: Laboratory for Prenatal Diagnostics of Inherited Diseases, Ott's Institute of Obstetrics and Gynecology RAMS, Saint-Petersburg, Russia. ankiselev@yahoo.co.uk
authors.forename: Anton
authors.initials: A
authors.lastname: Kiselev
authors.forename: Anna
authors.initials: A
authors.lastname: Egorova
authors.forename: Antti
authors.initials: A
authors.lastname: Laukkanen
authors.forename: Vladislav
authors.initials: V
authors.lastname: Baranov
authors.forename: Arto
authors.initials: A
authors.lastname: Urtti
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000008:administration & dosage*; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D006367:HeLa Cells; D006801:Humans; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry*; D011107:Polylysine / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014162:Transfection; D019076:Transgenes / Q000235:genetics
chemical_list: D010455:Peptides; D011108:Polymers; D011107:Polylysine; D004247:DNA