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XIth Symposium on Cationic Polymerization and Related Ionic Processes
Partially hydrolyzed poly(n-propyl-2-oxazoline) : synthesis, aqueous solution properties, and preparation of gene delivery systems
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 degrees C at varying N/P (amine-to-phosphate groups) ratios. They underwent structural changes upon temperature variations 65-25-37 degrees C depending on N/P. 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
Partially Hydrolyzed Poly(<i>n</i>‑propyl-2-oxazoline): Synthesis, Aqueous Solution Properties, and Preparation of Gene Delivery Systems
Random copolymers of <i>n</i>-propyl-2-oxazoline and
ethylenimine (PPrOx–PEI) were prepared by partial acidic hydrolysis
of polyÂ(<i>n</i>-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