Synthesis and characterization of pseudopoly(amino acids). New polymers for medical applications

An important obstacle to the clinical use of degradable polymers is the possible toxicity of the polymer degradation products. We have recently prepared a series of poly(amino acids) in which we replaced conventional peptide bonds in the polymer backbone by a variety of 'non-amide' linkages. The resulting materials can best be regarded as 'pseudo'-poly(amino acids). Preliminary results indicate that 'pseudo'-poly(amino acids) tend to retain the low toxicity of the amino acids, while at the same time exhibiting significantly improved polymer engineering properties. Polymerization reactions involving the side chains of naturally occurring amino acids proceed readily and lead to the formation of linear polymers of high molecular weight. So far, four new pseudo-poly(amino acids) have been prepared, which all show significantly improved engineering properties relative to the corresponding, conventional poly(amino acids).