ИСТИНА

Heteroarm bis-hydrophilic (ionic/non-ionic) star-shaped copolymers (star-shaped copolymers comprising several cationic arms of exhaustively quaternized poly(N,N-dimethylaminoethyl methacrylate) and one arm of poly(ethylene oxide)) interacting with linear polyelectrolytes bearing opposite charge (anionic homopolyelectrolytes such as poly(sodium styrenesulfonate) and poly(acrylic acid)) in aqueous media can form nanosized vesicular interpolyelectrolyte comlexes (IPECs), also referred to as interpolyelectrolytes polymersomes (IPECsomes). At 1:1 charge-to-charge ratio between the oppositely charged polymeric components in their mixtures, such IPECsomes are considered to be built up up from an insoluble IPEC wall, which is sandwiched between two (inner and outer) hydrophilic poly(ethylene oxide) brushes. Star-shaped topology of one of the polymeric components involved in the interpolyelectrolyte interaction forces morophology of the formed IPECs into vesicular shape, which is rare for such complex macromolecular structures. At the same time, too many ionic arms of the star-shaped polymeric component can induce pronounced clusterization (and even merging) of the IPECsomes. The considered macromolecular co-assemblies of vesicular morphology appear to be of considerable interest as (multi)functional nanocontaines and nanoreactors for variuos needs of medicine, biotechnology, catalysis, diagnostics, etc. Changing chemical nature of the linear polymeric component, one can impart (enhance) stimuli-sensitivity to the IPECsomes. When a strong anionic polyelectrolyte, such as poly(sodium styrenesulfonate), is complexed with the cationic star-shaped copolymer, the IPECsomes are insensitive (or weakly sensitive) to variations in pH and ionic strength of the surrounding aqueous medium. At the same time, they can clearly respond (disintegrate) to proper changes (e.g., via a pH-jump or a jump of ionic strength) of the above parameters if a weak anionic polyelectrolyte, such as poly(acrylic acid), is used as the linear polymeric component. Such stimuli-sensitive IPECsomes can hold promise as advanced nanocontainers for targeted delivery and further controlled release of (bio)payloads, where pH or/and ionic strength of the surrounding aqueous medium would act as a trigger. (p. 18)