4. Discussion
Our results show that alginate polymers can be modified with
norbornene and tetrazine to create alginate hydrogels with a widerange
of mechanical properties without the input of external energy,
crosslinkers, or catalysts. While recent work has used similar
click chemistry for localized drug delivery, this work presents the
first use of the tetrazineenorbornene click reaction to covalently
crosslink polysaccharides into hydrogels [29,38]. Crosslinking of
alginate by different methods has been extensively explored to
make covalently crosslinked hydrogels that are mechanically
robust, but these chemistries lack the cytocompatibility inherent in