Dynamic covalent bonding based polysaccharide hydrogels and their applications in wound dressings: A review

Polysaccharide hydrogels have emerged as pivotal wound dressings due to their inherent biocompatibility and extracellular matrix-mimicking properties. However, conventional systems employing permanent covalent or physical crosslinks suffer from irreversibility, poor self-repair capacity, and limited responsiveness that compromise clinical efficacy. To address these challenges, dynamic covalent bonding strategies have been innovatively integrated into polysaccharide networks, enabling unprecedented functionalities through reversible bond reconfiguration. These advanced hydrogels exhibit intelligent characteristics including self-healing, injectable adaptability, and stimulus-responsive drug release, achieved through precisely engineered imine, borate ester, disulfide, and other dynamic linkages, which allows the polysaccharide hydrogels to better adapt to different shapes of wounds and self-repair after damage to extend the life of the dressing. In this review, we summarize different types of dynamic covalently cross-linked polysaccharide hydrogels and their applications as wound dressings in wound repair, discuss the prospects of polysaccharide hydrogels based on dynamic covalent bonding, and address some of the associated limitations.