The effect of hydrazide linkers on hyaluronan hydrazone hydrogels.

•Three hyaluronan derivatives (aldehyde, unsaturated aldehyde and acylated aldehyde) were crosslinked by linear or branched hydrazide to form non-toxic hydrogels.•Water-soluble acylated hyaluronan-aldehyde formed hydrogels showed similar mechanical properties, e.g. Youngs’ moduli, as non-acylated hyaluronan-aldehyde.•Unsaturated hyaluronan-aldehyde formed hydrogels with higher conversion rate and higher stiffness than saturated hyaluronan-aldehyde.•The conversion rate of aldehyde to imine was the lowest for larger Arm-PEG-hydrazide crosslinkers.•The conversion rate and stiffness were similar for short bi- and tri-functional crosslinkers.