Biodegradable polymer phosphazenes

Crommen, J.H.L., Schacht, E.H., and Mense, E.H.G. (1992). Biodegradable Polymers. 2. Degradation Characteristics of Hydrolysis-Sensitive Poly[(Qrgano)Phosphazenes]. Biomaterials, 13, 601-611. 

Recent developments in the polyphosphazene chemistry have been re-viewed. The role of polyphosphazenes as biodegradable polymers as hydrogels for tissue engineering and as induced helical polymers has been discussed. Preparation and application of poly(thionyl phosphazenes) are discussed in two review chapters. ... 

Other types of biodegradable polymer such as poly(ortho esters), poly-(organo phosphazenes) and polyanhydrides have been described. However, they have been less developed than polyesters. 

Hydroxyl-functionalized cinnamic acid derivatives such as p-coumaric acid (p-hydroxycinnamic acid), ferulic acid, and sinapinic acid are attractive monomers for syntheses of high-performance polyesters. The obtained polyesters are also expected to be biodegradable in the case of copolymerization with aliphatic hydroxy acids such as lactic acid. Tanaka et al reported the thermal polycondensation of p-coumaric acid at 550 °C without any catalyst under high pressure up to 80 kbar (in the solid state) in 1975. They obtained red or brownish-red hard solids insoluble in conventional organic solvents. Higashi and his co-workers synthesized copolyesters of p-coumaric acid and 4-hydroxybenzoic acid or their methoxy substitutions (ferulic acid, vanillic acid, or syringic acid) by polycondensation using hexachlorocyclotri(phosphazene) in pyridine in 1981. The obtained polymers that exhibited UV spectra different... 

Deng, M., Nair, L.S., Nukavarapu, S.P., Kumbar, S.G., Jiang, T., et al., 2010c. In situ porous structures a unique polymer erosion mechanism in biodegradable dipeptide-based poly-phosphazene and polyester blends producing matrices for regenerative engineering. Advanced Functional Materials 20 (17), 2794—2806. 

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