Chemical syntheses of biodegradable polymers

Commercially available synthetic biodegradable polymers had been limited to aliphatic polyesters until polyesters containing aromatic moieties recently appeared on the market. Currently, several different types of biodegradable polymers have been developed and are being evaluated for practical uses. The present article reviews recent advances in chemical syntheses of biodegradable polymers from the standpoint of molecular design. Thus, synthetic biodegradable polymers are herein classified into three groups: (1) polyesters, (2) polymers containing both ester and other heteroatom-containing linkages in the main chains, and (3) polymers with heteroatom-containing linkages other than ester linkages in the main chains. Progress in the synthesis of the representative polymers in each category is described with emphasis on controlled synthesis, and their biodegradability is discussed in relation to the molecular structure. (C) 2001 Elsevier Science Ltd. All rights reserved.