Biodegradable polyethylene glycol poly copolymer

Minamitake, Y., Gref, R., Hrkach, J., Peracchia, M. T., Domb, A., and Langer, R., 1994, Injectable nanospheres made of biodegradable polyethylene glycol-poly(lactic-co-glycolic) acid diblock copolymers. Paper in preparation. 

Saito N, Okada T, Horiuchi H, Murakami N, Takahashi J, Nawata M, et al. Biodegradable poly-D,L-lactic acid-polyethylene glycol block copolymers as a BMP delivery system for inducing bone. J Bone Jt Surg 2001 83 S92-8. 

Wang used reactive-extrusion polymerization with 2,5-di-methyl-2,5-di-t-bu-tylperoxy hexane to prepared a graft copolymer, (11), by free radically grafting polyethylene-glycol malonic acid onto the biodegradable substrate of poly((3-hydroxybutyrate-co- p-hydroxy valerate). 

The biodegradablility of blends of poly(3-hydroxybutyrate) with a copolymer of poly(3-hydroxybutyrate) and poly(3-hydroxyvalerate) is better than that of each component taken separately. This is an advantage found in many other blends of biodegradable plastics. The same fact is observed for blends of poly(3-hydroxy-butyrate) and polyethylene glycol. This is due to the hydrophilic character of polyethylene glycol. 

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