Polyphosphoesters

Polyphosphoesters are biomaterials composed of phosphorus-incorporated monomers. These polymers consist of phosphates with two R groups, one in the backbone and the other as a side group. They have good biocompatibility and a similarity to biomacromolecules such as DNA and RNA. Polyphosphoesters are divided into two different classes polyphosphonates with an alkyl or aryl R group and polyphosphates with an alkoxy or aryloxy R group. Polyphosphoesters are copolymerized with polyethers and polyesters to enhance their physical properties. They have been studied as scaffolds for bone tissue regeneration [8]. 

Biodegradable Polymeric Biomaterials An Updated Overview, in Biomedical Engineering Handbook, 2nd edn., ed. by J.D. Bronzino (CRC Press, Boca Raton, Florida, 

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Some other synthetic biodegradable polymers such as poly(alkyl cyanoacrylates), polyphosphazenes, poly(ortho esters),poly(ethylene ter-ephthalate)-poly(ethylene glycol) copolymer and poly(ether ester amide)s have been of great interest in many fields. 

The synthetic flexibility and versatile adaptability has made polyphos- 

Polyacetal and poly(ortho ester)-poly(ethylene glycol) graft copolymer thermogels was reported by Schacht et al. A series of materials having lower critical solution temperature (LCST) between 25 and 60 °C were prepared, but no erosion or drug release studies have as yet been completed. 

Whistler, J. Bemiller and E. Paschall, eds.. In Starch Chemistry and Technology, Academic Press, New York, 1984. 

libuchi, K. Matsui, T. Kawai, K. Sasaki, O. Suzuki, S. Kamakura and S. Echigo, Int. J. Oral Maxillofac. Surg., 2010, 39, 161. 

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Zhao Z and Eong LKW. Polyphosphoestes in drug and gene delivery. Adv Drug Deliv Rev, 2003, 55, 483 99. 

Polyphosphoesters are a novel class of polymers being studied for applications in drug delivery and tissue engineering (Fig. 6). The individual components can be... 

Figure 6 (Top) General structure of Polyphosphoesters. R and R can be varied to obtain polymers with varied physicochemical properties ranging from gels, to elastomers, to amorphous polymer particles. (Bottom) Example structure of a polylactide-co-ethylphosphate copolymer.

Polyphosphoesters Synthetic Polyaddition, ringopening polymerization Available as water-soluble and water-insoluble types... 

Polyanhydride Polyorthoester Polyphosphazene Polyphosphoester Polyphosphate Polyphosphonate Polyphosphite... 

Table 8 Common phosphorus-containing polymers—polyphosphoesters...

Cationic polymers, such as poly(L-lysine) (PEL), polyethylenimine (PEI), chitosan, polyamidoamine (PAMAM) dendrimers, poly(2-dimethylamino) ethyl methacrylate, and polyphosphoesters, condense DNA to form compacted polyplexes. ° The size and the stability of polyplexes depend on the ratio of cations vs. anions, temperature, ionic strength, and the solvent. Stability of polyplexes can be enhanced by conjugating PEG to the polycations or by using PEG-containing block or graft polymers that form micelles. Small cationic peptides are also able to condense DNA, however, six-consecutive-cations is the minimal requirement to achieve this effectively. 

Arguably the most important amorphous ionomer is sulfonated polystyrene (SPS). Other ionomers include poly(styrene-rfln-methacrylic acid) (SMAA), polyurethanes, siloxanes, butadiene-based elastomers, ethylene-propylene-diene terpolymers, acrylates and methacrylates, polyphosphoesters, polyimides, and many others. ... 

General structure of polyphosphoesters where R = divalent organic groups. 

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