Effect of Homochirality of Dipeptide to Polymers' Degradation.

As natural polymer materials, proteins are readily biodegradable, interestingly, the synthetic polyamides (PAs) that are based on the same amide bonds (also called peptide bonds in proteins) are barely degradable. Whether did the chirality and configuration of the amino acids play an important role. By using different configuration of amino acids, 4 types of polyamide-imides (PAIs) containing dipeptides of LL, DL, LD, and DD configurations, respectively, were synthesized. It was found that the PAIs based on natural LL configuration of dipeptide structure are much more readily biodegradable than those based on non-natural LD, DL, and DD configuration of dipeptides. It was confirmed that the natural L-configuration of amino acids play a critical role in degradability of proteins. And it also suggested that different type and amount of peptide fragments can be introduced in polymer to create series of polymer materials that can be biodegraded at controllable speed.