In vitro antibacterial activity and cytotoxicity of Thermo-sensitive composite hydrogels with encapsulated CuFe-LDH

Copper‑iron layered double hydroxides (CuFe-LDHs) with varying Cu/Fe atomic ratios and intercalated CO 3 2− /HCO 3 − anions were successfully synthesized via a solvothermal method. The as-prepared CuFe-LDHs exhibited a sheet-like morpHology, with particle size increasing as the Cu/Fe ratio increased. Their antibacterial activity against Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ) was highly dependent on the Cu/Fe ratio. Among them, CuFe-LDH-3 (Cu/Fe = 3:1) demonstrated the highest antibacterial efficacy, achieving 100 % inhibition at 0.05 mg/mL for S. aureus and 0.5 mg/mL for E. coli . This was attributed to the synergistic action of the released Cu 2+ and Fe 3+ ions and peroxidase-mimicking ROS generation. Moreover, CuFe-LDH-3 was incorporated into a hydroxypropyl methylcellulose ((HPMC)/hyaluronic acid(HA)/glycerol(Gl) hydrogel matrix to develop a thermo-sensitive composite hydrogel (CuFe-LDH/HHG). The resulting composite hydrogel exhibited thermo-sensitive sol-gel transition between 34 and 36 °C. In addition, the 0.1 % ( W / V ) CuFe-LDH/HHG hydrogel displayed excellent antibacterial activity, good biocompatibility , and endothelial cell proliferation promotion. This study presents a novel thermo-sensitive antibacterial composite hydrogel system with remarkable antibacterial properties and biocompatibility, highlighting its potential for wound healing and biomedical applications. • CuFe-LDHs possess peroxidase-like activity to produce large amounts of ROS. • HPMC 14 /HA 4 /Gl 35 hydrogel exhibits distinct thermo-sensitivity. • CuFe-LDH/HHG had excellent antibacterial performance along with biocompatibility.