Statements
Polyelectrolyte complexes and their potential as capsule material
The complexes formed by pairs of oppositely charged polyelectrolytes have quite unusual properties: they are insoluble in almost any solvent except concentrated electrolyte solutions, can swell in water and take up ions to various extents, and can be mechanically very strong. In the form of thin films – as prepared by the so-called layer-by-layer technique – they can be manipulated in many ways so as to tune their permeability to specific purposes. From a scientific point of view there is still al lot about these materials that we do not know or understand (thermodynamics, material properties, kinetic behaviour), but it is beyond any doubt that they are most appropriate for making capsules which, in turn, can probably be post-modified for the purpose of drug-targeting. As far as I know, this has not yet been done but it should be a matter of months rather than years. Since polyelectrolytes can be chosen from a wide range of available polymers, the proper variety for a given application (e.g., food-grade) is probably already available. Many new alleys can still be explored here.
Prof. Dr. Martien Cohen Stuart
Laboratory of Physical Chemistry and Colloid Science
Wageningen University
