Fluorinated Polyphosphazene Coatings Using Aqueous Nano-Assembly of Polyphosphazene Polyelectrolytes

Fluorinated polyphosphazenes, such as poly[bis(trifluoro​ethoxy)phosphazene], PTFEP, attract significant interest as hydrophobic and biocompatible materials for industrial and life science applications. A novel class of fluorinated polyphosphazenes, which include ionic and fluorine containing moieties, is gaining recognition as a macromolecular system capable of nano-assembly into highly hydrophobic materials. The present chapter reviews synthetic approaches to ionic fluoropolymers with polyphosphazene backbones and summarizes their solution behavior. It then focuses on nano-assembly of fluorinated polyions using the layer-by-layer (LbL) deposition technique - a route to creating high-precision fluorinated surfaces for biomaterials applications. This approach enables highly controlled linear film growth with superior persistence of layering and affords a high degree of hydrophobicity to the resultant coating. Moreover, these nano-films display superb biocompatibility, as demonstrated by the hemolysis of whole blood and protein adsorption studies in vitro, and display the ability to self-heal at near physiological conditions. Finally, nano-assembled fluorinated coatings enable controlled encapsulation and release of bioactives. The multi-functionality of fluorinated polyphosphazene nano-films, along with their precision supramolecular architecture, suggests their broad potential applications as coatings for cardiovascular stents, catheters, and various implants.