Polyanhydride-based materials

Chemical structure of polyanhydride-based injectable materials. 

In addition to PEG-based materials, other materials such as polyphosphoester, polyanhydrides, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (Pluronic), oUgo(poly(ethylene glycol) fumarate) and hyaluronic acid... 

The development of new polyanhydrides has sparked researchers to developed new device fabrication and characterization techniques, instrumentation, and experimental and mathematical models that can be extended to the study of other systems. The growing interest in developing new chemistries and drug release systems based on polyanhydrides promises a rich harvest of new applications and drug release technologies, as well as new characterization techniques that can be extended to other materials. Future endeavors will likely focus on multicomponent polyanhydride systems, combining new chemical functionalities to tailor polyanhydrides for specific applications. 

Hydrolysis is the most common mechanism of polymer degradation in biomaterials. Of the linkages that commonly occur in polymers, the anhydride linkage is one of the least stable in the presence of water. In fact, polyanhydride polymers are so sensitive to water that they are unsuitable for many potential applications. However, the potential for rapid hydrolysis of the polymer backbone makes anhydride-based polymers attractive candidates as biodegradable materials. 

Kipper, M.J., Wilson, J.H., Wannemuehler, M.J., Narasimhan, B., 2006. Single dose vaccine based on biodegradable polyanhydride microspheres can modulate immune response mechanism. Journal of Biomedical Materials Research Part A 76, 798—810. 

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