A Dynamically Crosslinked Hydrogel with Injectable and Antibacterial Properties

Abstract

The clinical management of chronic wounds is frequently challenged by bacterial infection and biofilm formation. To address this, we developed an injectable hydrogel, denoted as AMCS@ODex, via dynamic Schiff base bonding between amide-modified chitosan (AMCS) and oxidized dextran (ODex). This crosslinking strategy not only mitigated the inherent limitations of chitosan, such as poor solubility and mechanical properties, but also endowed the hydrogel with excellent shear-thinning behaviors. AMCS@ODex exhibited antibacterial efficacy against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA), and the antibacterial rates against E. coli and MRSA were 58% and 73%, respectively. Furthermore, it effectively disrupted pre-formed MRSA biofilms, leading to a disruption rate approximately 50%. Critically, the hydrogel exhibited outstanding biocompatibility, supporting over 90% viability of L929 fibroblast cells. By integrating good antibacterial performance, with desirable mechanical properties and high biocompatibility, the AMCS@ODex hydrogel presents potential biomedical applications, particularly in the fight against bacterial infections.

Keywords

hydrogel / Schiff base / antibacterial activity / chitosan