Copper Mediated And Copper Free "Click" Decoration Of Polysialic Acid For Rgd-Modification And Hydrogel Formation

This paper describes and compares the copper-catalyzed and copper-free "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 H-1-NMR spectroscopy and mass spectrometry as well as MS/MS experiments identifying the non-hydrolyzable crosslinks.