Fabrication and Swelling of Semi‐ IPN Xerogels Containing Supergiant Polysaccharides for Sustained Gallic Acid Release

ABSTRACT Semi‐interpenetrating polymer network (semi‐IPN) hydrogels were developed by polymerizing poly(2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid) (PAMPS) network, chemically crosslinked with ethylene glycol dimethacrylate (EGDMA), in the presence of two algal polysaccharides—sacran and κ‐carrageenan (κC). Gallic acid (GA) was post‐loaded into the xerogels as a therapeutic agent for sustained release, where it interacted with the hydroxyl groups of the polysaccharide matrix, facilitating its efficient loading within the network. The resulting xerogels exhibited excellent swelling behavior and, in the hydrogel state, desirable mechanical properties such as flexibility and structural integrity, largely due to the unique water retention capacity and extensive molecular interactions facilitated by sacran and κC. The densely interconnected polymeric network effectively regulated the diffusion of GA, enabling prolonged and sustained release, thereby significantly enhancing its bioactivity. The released GA demonstrated strong antioxidant properties and effective antimicrobial effect, especially effective against Gram‐positive bacteria like Staphylococcus aureus , and Gram‐negative bacteria such as Escherichia coli . Cytocompatibility assays using Raw264.7 cells confirmed the excellent biocompatibility of the hydrogels, likely due to the naturally cell‐friendly properties of sacran and κC. Collectively, these findings emphasize the strong potential of these semi‐IPN xerogels/hydrogels as versatile carriers for the sustained delivery of bioactive compounds, suitable for biomedical applications addressing oxidative stress and bacterial infections.