Polyion reagents

Polyhydroamino acids, thermal, reactions catalyzed by,20 379 aminations, 20 405-408 decarboxylations, 20 394-405 hydrolytic, 20 380-394 metabolic pathways, 20 408 Polyion reagents, seespecific substances Polymer chains, growth of, on Ziegler catalysts, 19 225-228... 

Each polyion pair which yielded a stable membrane was removed from the receiving bath and treated. In general, quintuple washings with an excess (50 ml) of PBS were required to remove all traces of the polymeric reagents. The PBS also simulated the osmotic pressure which the capsule, and mammalian cells, would encounter in vivo. For several polyanion-polycation systems the membranes which were produced were not sufficiently strong to survive the rinsings. Leaky membranes and the complete collapse of the capsule were two common failures. 

PECs are the association complexes mainly formed between oppositely charged particles (e.g., polymer-polymer, polymer-drug, polymer-surfactant, polymer-protein). These complexes are formed due to electrostatic interaction between oppositely charged polyions. This interaction avoids the use of chemical cross-linking agents that can reduce the possible toxicity and other undesirable effects of the reagents. The PECs formed between a poly acid and poly base are less affected by the pH variation of the dissolution medium. The complexation, between DNA and chitosan, has been extensively studied in the development of delivery vehicle for gene therapy and oral vaccination. 

Morawetz and coworkers have also studied the catalysis of ionic reactions by polyelectrolytes [26—28]. These authors argue that the fluctuations of the electrostatic potential in a polyelectrolyte solution may in principle be studied by monitoring the effect a polyelectrolyte has upon the rate of reaction involving two small species. Qualitatively, if the charge of these two species is opposite to that of the polyion, the reagents... 

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