摘要:
Materials, methods, and systems for biorthogonal ligation of hydrogel labels to crosslinked-natural polymer hydrogels are provided. A heterobifunctional linker includes a peptide-reactive activated functional group on the heterobifunctional linker, including an activated amine-reactive functional group, an activated thiol-reactive functional group and being reactive with a hydrogel comprising a crosslinked natural polymer. The heterobifunctional linker also includes a photocaged reactive group including a photocaged hydroxylamine, a photocaged alkoxyamine, a photocaged hydrazide, a photocaged amine, a photocaged tetrazine, or a photocaged alkyne-containing moiety. The peptide-reactive activated functional group does not include an azide.