title: Phosphorus dendrimers as carriers of siRNA--characterisation of dendriplexes.
abstract: There are many types of dendrimers used as nanomolecules for gene delivery but there is still an ongoing search for ones that are able to effectively deliver drugs to cells. The possibility of gene silencing using siRNA gives hope for effective treatment of numerous diseases. The aim of this work was to investigate in vitro biophysical properties of dendriplexes formed by siRNA and cationic phosphorus dendrimers of 3rd and 4th generation. First, using the ethidium bromide intercalation method, it was examined whether dendrimers have an ability to form complexes with siRNA. Next, the characterisation of dendriplexes formed at different molar ratios was carried out using biophysical methods. The effects of zeta potential, size and changes of siRNA conformation on the complexation with dendrimers were examined. It was found that both phosphorus dendrimers interacted with siRNA. The zeta potential values of dendriplexes ranged from negative to positive and the hydrodynamic diameter depended on the number of dendrimer molecules in the complex. Furthermore, using circular dichroism spectroscopy it was found that cationic phosphorus dendrimers changed only slightly the shape of siRNA CD spectra, thus they did not induce significant changes in the nucleic acid secondary structure during complex formation.
authors.affiliation: Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., Lodz 90-236, Poland. malgosiaferenc@wp.pl
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Ferenc
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Pedziwiatr-Werbicka
authors.forename: Katarzyna E
authors.initials: KE
authors.lastname: Nowak
authors.forename: Barbara
authors.initials: B
authors.lastname: Klajnert
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Majoral
authors.forename: Maria
authors.initials: M
authors.lastname: Bryszewska
mesh_terms: D001703:Biophysics / Q000379:methods; D002942:Circular Dichroism; D050091:Dendrimers / Q000737:chemistry*; D004996:Ethidium / Q000737:chemistry; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics / Q000628:therapy; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D010758:Phosphorus / Q000737:chemistry*; D051562:Proto-Oncogene Proteins c-bcr / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D050091:Dendrimers; D034741:RNA, Small Interfering; D010758:Phosphorus; D051562:Proto-Oncogene Proteins c-bcr; D004996:Ethidium