Structural relaxation in a Schiff base‐crosslinked aldehyde modified xanthan gum/gelatin hydrogel: Experimental and numerical validation using linear poroelasticity model

Abstract Hydrogels hold immense promise in biomedical applications due to their biocompatibility, high water content, and versatile fabrication. This study focuses on the mechanical behavior of a novel polysaccharide/protein hybrid hydrogel, GEL‐AXG, synthesized via a Schiff base reaction between aldehyde‐modified xanthan gum (AXG) and gelatin (Gel). Hydrogel samples with varying AXG‐to‐Gel ratios were subjected to unconfined compression tests to assess their mechanical properties. The observed stress‐relaxation mechanism in deformed hydrogels primarily involves water migration. To quantify these mechanical properties, we applied the linear poroelasticity theory. Our results highlight that Gel‐AXG hydrogels with a 2:1 AXG‐to‐Gel ratio exhibit significantly higher peak and equilibrium stresses. This enhancement can be attributed to increased crosslink density and reduced dangling chain presence. Moreover, the linear poroelasticity formulation yielded a shear modulus of G = 44.91 ± 0.25 kPa for Gel‐AXG hydrogels with a 1:2 AXG‐to‐Gel volume ratio, which we identified as our optimized hydrogel.