title: Formation and characterization of DNA-polymer-condensates based on poly(2-methyl-2-oxazoline) grafted poly(L-lysine) for non-viral delivery of therapeutic DNA.
abstract: Successful gene delivery systems deliver DNA in a controlled manner combined with minimal toxicity and high transfection efficiency. Here we investigated 15 different copolymers of poly(l-lysine)-graft-poly(2-methyl-2-oxazoline) (PLL-g-PMOXA) of variable grafting densities and PMOXA molecular weights for their potential to complex and deliver plasmid DNA. PLL(20)g(7)PMOXA(4) formed at N/P charge ratio of 3.125 was found to transfect 9 ± 1.6% of COS-7 cells without impairment of cell viability. Furthermore these PLL-g-PMOXA-DNA condensates were internalized 2 h after transfection and localized in the perinuclear region after 6 h. The condensates displayed a hydrodynamic diameter of ∼100 nm and were found to be stable in serum and after 70 °C heat treatment, moreover the condensates protected DNA against DNase-I digestion. The findings suggest that DNA-PMOXA-g-PLL condensate formation for efficient DNA-delivery strongly depends on PMOXA grafting density and molecular weight showing an optimum at low grafting density between 7 and 14% and medium N/P charge ratio (3.125-6.25). Thus, PLL(20)g(7)PMOXA(4) copolymers might be promising as alternative to PLL-g-PEG-DNA condensates for delivery of therapeutic DNA.
authors.affiliation: Cells and BioMaterials, Department of Materials, ETH Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: von Erlach
authors.forename: Sven
authors.initials: S
authors.lastname: Zwicker
authors.forename: Bidhari
authors.initials: B
authors.lastname: Pidhatika
authors.forename: Rupert
authors.initials: R
authors.lastname: Konradi
authors.forename: Marcus
authors.initials: M
authors.lastname: Textor
authors.forename: Heike
authors.initials: H
authors.lastname: Hall
authors.forename: Tessa
authors.initials: T
authors.lastname: Lühmann
mesh_terms: D000818:Animals; D019556:COS Cells; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry; D002522:Chlorocebus aethiops; D004247:DNA / Q000737:chemistry*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011073:Polyamines; D011107:Polylysine / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*
chemical_list: D011073:Polyamines; D011108:Polymers; C117403:poly(2-methyl-2-oxazoline); D002686:Chitin; D011107:Polylysine; D004247:DNA