Copper Mediated and Copper Free “Click” Decoration of Polysialic Acid for RGD-Modification and Hydrogel Formation

摘要

This paper describes and compares the copper-catalyzed and copperfree “click” reaction of N-azido, N-alkynoyl and N-oxanorbornadienyl polysialic acid for the formation of hydrogels and cyclic RGD conjugates. To proof the molecular mechanism of the crosslinking reaction, the crosslinking and conjugation reactions were studied in detail on a molecular level by 1H-NMR spectroscopy and mass spectrometry as well as MS/MS experiments identifying the non-hydrolyzable crosslinks.