The PPM via polymeric active esters became an attractive tool after the first introduction by Jatzkewitz and later picked up by Ferruti et al. and Ringsdorf et al. . The reaction of activated esters with amines leads to the formation of stable amide bonds which are of course most common in biological systems. Additionally, there is no need to use of potentially toxic (metal) catalysts or other chemical reagents making them an attractive material in biomedical research . Apart from alkyne-azide click chemistry ,