Antioxidant-biocompatible and stable catalase-based gelatin-alginate hydrogel scaffold with thermal wound healing capability: immobilization and delivery approach.

Hydrogel-based matrix prepared using biopolymers is a new frontier of emerging platforms for enzyme immobilization for biomedical applications. Catalase (CAT) delivery can be effective in inhibiting reactive oxygen species (ROS)-mediated prolongation of the wound healing process. In this study, to improve CAT stability for effective application, gelatin(Gel)-alginate (Alg) biocompatible hydrogel (Gel-Alg), as immobilization support, was prepared using calcium chloride as an ionic cross-linker. High entrapment efficiency of 92% was obtained with 2% Gel and 1.5% Alg. Hydrogel immobilized CAT (CAT-Gel-Alg) showed a wide range of pH from 4 to 9 and temperature stability between 20 to 60 °C, compared to free CAT. CAT-Gel-Alg kinetic parameters revealed an increased K m (24.15 mM) and a decreased V max (1.39 µmol H 2 O 2 /mg protein min) × 10 4 . CAT-Gel-Alg retained 52% of its original activity after 20 consecutive catalytic runs and displayed improved thermal stability with a higher t 1/2 value (half-life of 100.43 vs. 46 min). In addition, 85% of the initial activity was maintained after 8 weeks' storage at 4 °C. At 24 h after thermal injury, a statistically significant difference in lesion sizes between the treated group and the control group was reported. Finally, our findings suggest that the superior CAT-Gel-Alg stability and reusability are resonant features for efficient biomedical applications, and ROS scavenging by CAT in the post-burn phase offers protection for local treatment of burned tissues with encouraging wound healing kinetics.