Polyphosphazenes hydrogel membranes

It has been demonstrated that a variety of different polyphosphazenes can be developed as biomaterials, membranes or hydrogels, bioactive polymers, and bioerodible polymers. As with most new areas of polymer chemistry and biomaterials science, molecular design forms the basis of most new advances, but the rate-controlling step is the testing and evaluation of the materials in both in vitro and in vivo environments. This is particularly true for polyphosphazenes where the availability of research quantities only has limited the... 

Some of the most useful polyphosphazenes are fluoroalkoxy derivatives and amorphous copolymers (11.27) that are practicable as flame-retardant, hydrocarbon solvent- and oil-resistant elastomers, which have found aerospace and automotive applications. Polymers such as the amorphous comb polymer poly[bis(methoxyethoxyethoxy)phosphazene] (11.28) weakly coordinate Li " ions and are of substantial interest as components of polymeric electrolytes in battery technology. Polyphosphazenes are also of interest as biomedical materials and bioinert, bioactive, membrane-forming and bioerodable materials and hydrogels have been prepared. 

Hydrogels and amphiphilic membranes Poly(carbophosphazenes) and poly(thiophosphazenes) New condensation syntheses NLO and high refractive index polymers Microencapsulation of mammalian cells (PCPP) Polyphosphazene polymer blends and IPN s Borazine derivatives Poly(phosphazophosphazenes)... 

A number of general reviews on polyphosphazenes have appeared. Specific reviews on polyphosphazenes deal with radiation graft polymerization, anionic polymerization, hydrogel microspheres,controlled biodegradability,coatings, and membrane separation. 

AUcock, H. R., and Kwon, S., 1989, An ionically cross-linkable polyphosphazene Poly(bis(carboxylatophenoxy)phosphazene) and its hydrogel and membranes. Macromolecules 22 7 5-79. 

Water-soluble polyphosphazenes can be crosslinked either by gamma-radiation or by di- or tri-valent cations. The resultant materials imbibe or extrude water in response to changes in temperature, pH, or cations. These hydrogels offer the prospect of uses in responsive membranes, devices for the controlled delivery of dmgs, enzyme immobilization and mediation media, and tissue engineering. 

---