Designing Nanofibrillar Macroporous Hydrogels via Aqueous Foam Templating

The emulsion templating method is a versatile approach for fabricating macroporous hydrogels, appreciated for its simplicity, high porosity, and the formation of interconnected pores. However, traditional templates using liquid phases as the dispersed medium often suffer from challenges like organic solvent residues, limiting their applicability in biomaterials. To address these limitations, air-in-water foams have emerged as a promising alternative but are constrained by the high surface tension of prepolymer solutions, which hampers the formation of stable templates. In this study, tannic acid (TA)-modified lysozyme amyloid nanofibrils (TA@AF) were integrated with gelatin methacrylate (GelMA) and methacryloylethylsulfobetaine (SBMA) monomers to stabilize air-in-water foams and fabricate nanofibrillar macroporous hydrogels (NMH) via free radical polymerization. The TA@AF nanofibrils played a dual role in controlling air bubbles and pore sizes and reinforcing the mechanical properties of the hydrogels. The resulting NMH hydrogels demonstrated excellent antioxidant and hemostatic capabilities while preventing protein adhesion. These attributes highlight the potential of air-in-water foam-templated nanofibrillar macroporous hydrogels as innovative materials for biomedical applications.