Stabilized amphiphilic poly(styrene-co-diene)-b-poly(ethylene oxide) aggregates

-isoprene (I) or butadiene (B)) prepolymers (bearing hydroxyl or benzyl bromide end groups) and ethylene oxide or mono-methyl poly(ethylene glycol) (PEGs) were used to prepare a series of PS-co-PD-b-PEO amphiphilic copolymers. Investigations on the association and self-assembly of copolymers in dilute organic and in mixed organic/water solutions have been carried out both by light scattering and microscopic measurements. Nanosized and microsized species have been observed. Their shape depends on the hydrophobic/hydrophilic blocks ratio as well as on the solvent composition. Attempts on stabilizing the morphology of the aggregates/micelles have been made by UV-induced cross-linking of diene entities. It has been found that in some experiments, the stabilization proceeds throughout morphological rearrangement determined by the solvent nature and by the cross-linking protocol

Synthesis of poly(styrene-co-diene)-block-polyglycidol. Self-association and stabilization of aggregates

A series of amphiphilic poly(styrene(S)-co-diene(D))-b-polyglycidol(G) block copolymers have been synthesized from a parent hydrophobic PS block. The block has been previously functionalized with double bonds of randomly distributed diene units (isoprene (I) or butadiene (B)). Hydrophilic PG blocks of different lengths have been introduced into the above prepolymers. Polymer aggregates of different size and shape have been obtained by dissolving the copolymers in organic and mixed organic/water solutions. The formation of nano-and microsized particles has been revealed by light scattering and microscopic studies. A protocol for preparation of aggregates of a tailored core/shell structure has been demonstrated. Stabilization of particles of the desired morphology with ongoing participation of double bonds in the diene units has been achieved by irradiation with UV light directly in solution

Characterization of polymer vector systems based on partially hydrolyzed polyoxazoline for gene transfection

In this work, partially hydrolyzed thermoresponsive polyoxazoline was used for complexation with DNA. The resulting polyelectrolyte complex particles were characterized by dynamic and electrophoretic light scattering. They showed narrow size distribution and hydrodynamic diameter of 183 +/- 5 nm at 65 degrees C. To improve stability of the system at physiological temperature, the particles were coated with cross-linked polymer shell on their surface. A cytotoxicity study indicated lower toxicity of the investigated systems compared to the referent polyethylenimine. In addition, the transfection ability of the resulting vector systems was evaluated by flow cytometry. Transfection efficiencies up to 65 % that of the referent polyethylenimine indicated the potential of the vectors for DNA delivery