title: Partially Hydrolyzed Poly(n-propyl-2-oxazoline): Synthesis, Aqueous Solution Properties, and Preparation of Gene Delivery Systems.
abstract: Random copolymers of n-propyl-2-oxazoline and ethylenimine (PPrOx-PEI) were prepared by partial acidic hydrolysis of poly(n-propyl-2-oxazoline) (PPrOx). Dynamic and electrophoretic light scattering and diffusion-ordered NMR spectroscopy were utilized to investigate aqueous solution properties of the copolymers. Above a specific cloud point temperature, well-defined nanoparticles were formed. The latter consisted of a core composed predominantly of PPrOx and a thin positively charged shell from PEI moieties that mediated formation of polyplexes with DNA. The polyplexes were prepared at 65 °C at varying N/P (amine-to-phosphate groups) ratios. They underwent structural changes upon temperature variations 65-25-37 °C depending on N/P. At N/P < 2, the polyplex particles underwent minor changes because of formation of a surface layer of DNA that acted as a barrier and prevented swelling and disintegration of the initial particles. Dramatic rearrangements at N/P ≥ 2 resulting in large swollen microgel particles were overcome by coating of the polyplex particles with a cross-linked polymeric shell. The shell retained the colloidal stability and preserved the physicochemical parameters of the initial polyplex particles while it reduced the high surface potential values. Progressive loss of cytotoxicity upon complexation with DNA and coating of polyplex particles was displayed.
authors.affiliation: Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Ghent University , Krijgslaan 281 S4, B-9000 Ghent, Belgium.
authors.forename: Maarten
authors.initials: M
authors.lastname: Mees
authors.forename: Emi
authors.initials: E
authors.lastname: Haladjova
authors.affiliation: Faculty of Pharmacy, Medical University of Sofia , 2 Dunav str., Sofia 1000, Bulgaria.
authors.forename: Denitsa
authors.initials: D
authors.lastname: Momekova
authors.affiliation: Faculty of Pharmacy, Medical University of Sofia , 2 Dunav str., Sofia 1000, Bulgaria.
authors.forename: Georgi
authors.initials: G
authors.lastname: Momekov
authors.forename: Pavletta S
authors.initials: PS
authors.lastname: Shestakova
authors.forename: Christo B
authors.initials: CB
authors.lastname: Tsvetanov
authors.affiliation: Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Ghent University , Krijgslaan 281 S4, B-9000 Ghent, Belgium.
authors.forename: Richard
authors.initials: R
authors.lastname: Hoogenboom
authors.forename: Stanislav
authors.initials: S
authors.lastname: Rangelov
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000235:genetics; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D006868:Hydrolysis; D008823:Micelles; D053758:Nanoparticles / Q000737:chemistry; D010081:Oxazolone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011094:Polyethyleneimine / Q000138:chemical synthesis / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D008823:Micelles; D012996:Solutions; C461065:trifluoromethyloxazolinone; D014867:Water; D010081:Oxazolone; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D004247:DNA