Hierarchically porous sodium alginate ultra-fine nanofiber-based aerogel fiber aggregates for enhanced lysozyme separation and purification

Achieving high throughput without compromising adsorption capacity remains a central challenge in bioprocessing. Herein, we report the rational design and fabrication of hierarchically porous sodium alginate nanofiber-based aerogel fiber aggregates (SANFAFs), prepared by integrating non-solvent-induced phase separation and centrifugal wet-spinning. The resulting material features a dual-scale pore network. Inter-fiber macropores facilitate convective mass transfer, while nanopores provide a large accessible specific surface area for protein binding. Benefiting from deprotonated carboxylate groups along the sodium alginate (SA) polymer backbone, SANFAFs possess inherent cation-exchange functionality. SANFAFs reach a static lysozyme adsorption capacity of 2842.43 ± 60.35 mg/g. Under column operation, they achieve a flow rate of 13.33 ± 1.52 L·h −1 at 0.1 bar and a dynamic binding capacity of 106.19 ± 3.81 mg/mL (10% breakthrough), surpassing commercial cation-exchange microspheres. Selective enrichment of lysozyme from pretreated egg white validates the practical performance of SANFAFs, highlighting their promise as chromatographic media for laboratory-scale protein bioprocessing.