title: Biophysical and transfection studies of an amine-modified poly(vinyl alcohol) for gene delivery.
abstract: Novel, multifunctional polymers remain an attractive objective for drug delivery, especially for hydrophilic macromolecular drugs candidates such as peptides, proteins, RNA, and DNA. To facilitate intracellular delivery of DNA, new amine-modified poly(vinyl alcohol)s (PVAs) were synthesized by a two-step process using carbonyl diimidazole activated diamines to produce PVAs with different degrees of amine substitution. The resulting polymers were characterized using NMR, thermogravimetric analysis (TGA), and gelpermation chromatography (GPC). Atomic force microscopy (AFM), dynamic light scattering photon correlation spectroscopy (PCS), and zeta-potential were used to investigate polyplexes of DNA with PVA copolymers. These studies suggest an influence of the polycation structure on the morphology of condensed DNA in polyplexes. Significant differences were observed by changing both the degrees of amine substitution and the structure of the PVA backbone, demonstrating that both electrostatic and hydrophobic interactions affect DNA condensation. DNA condensation measured by an ethidium bromide intercalation assay showed a higher degree of condensation with pDNA with increasing degrees of amine substitution and more hydrophobic functional groups. These findings are in line with transfection experiments, in which a good uptake of these polymer DNA complexes was noted, unfortunately, with little endosomal escape. Co-administration of chloroquine resulted in increased endosomal escape and higher transfection efficiencies, due to disruption of the endosomal membrane. In this study, the structural requirements for DNA complexation and condensation were characterized to provide a basis for rational design of nonviral gene delivery systems.
authors.affiliation: Philipps University Marburg, Department of Pharmaceutics and Biopharmacy, Ketzerbach 63, D-35032 Marburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wittmar
authors.forename: James S
authors.initials: JS
authors.lastname: Ellis
authors.forename: Frank
authors.initials: F
authors.lastname: Morell
authors.forename: Florian
authors.initials: F
authors.lastname: Unger
authors.forename: Jeanette Christine
authors.initials: JC
authors.lastname: Schumacher
authors.forename: Clive J
authors.initials: CJ
authors.lastname: Roberts
authors.forename: Saul J B
authors.initials: SJ
authors.lastname: Tendler
authors.forename: Martyn C
authors.initials: MC
authors.lastname: Davies
authors.forename: Thomas
authors.initials: T
authors.lastname: Kissel
mesh_terms: D016475:3T3 Cells; D000588:Amines; D000818:Animals; D002470:Cell Survival; D002738:Chloroquine / Q000494:pharmacology; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D010957:Plasmids / Q000008:administration & dosage* / Q000493:pharmacokinetics; D011142:Polyvinyl Alcohol / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity; D013329:Structure-Activity Relationship; D014162:Transfection / Q000379:methods*
chemical_list: D000588:Amines; D002738:Chloroquine; D011142:Polyvinyl Alcohol