Active polycondensation: From peptide chemistry to amino acid based biodegradable polymers

New polycondensation (PC) methods of polymer synthesis using non-traditional active derivative of dicarboxylic acids are reviewed. The new PC methods are named by general name "Active Polycondensation" (APC) to tell them from traditional low-temperature PC. The most of these methods are based on well known in peptide chemistry approaches to the activation of carboxylic groups. In the present paper the syntheses of heterochain polymers of basic, classes - polyamides, polyesters, polyurethanes, polyureas, and polybenzazoles by interaction of various active diesters with di- and polyfunctional nucleophiles are discussed in brief. Special attention is given to the synthesis of non-conventional heterochain macromolecular systems, in particular poly(ester amide)s (PEAs), composed of naturally occurring alpha-amino acids and other nontoxic building blocks like fatty diacids and diols - synthetic analogues of naturally occurring amino acid based polymers - peptides and proteins. The synthesis and proper-ties, biodegradation, and some practical applications of PEAs are discussed in brief.