Biomimetic Strategy to Fabricate Hierarchically Porous Zein Microreactors With a Hydrophobic Core–Hydrophilic Shell Architecture

Inspired by cellular compartmentalization, porous microreactors provide confined microenvironments that enhance molecular collisions and mass transport, thereby enabling advanced catalysis, drug delivery, and bioengineering. However, fabricating reactors with hierarchical hydrophobic-hydrophilic domains and tunable meso-/macroporosity remains challenging. Here, we report the scalable synthesis of zein mesoporous particles (ZMP) using an antisolvent precipitation method with inorganic salts as removable templates. The resulting ZMP exhibit tunable pore sizes (19-302 nm) and a robust core-shell structure, with hydrophobic α-zein subunits localized in the core and hydrophilic subunits forming a porous outer shell. Dual-dye fluorescence imaging and confocal microscopy confirm this amphiphilic architecture, while selective partitioning of hydrophobic and hydrophilic guest molecules further verifies the spatial heterogeneity. Enzymatic loading experiments demonstrate the potential of ZMP as active biocatalytic microreactors under mild conditions. These protein-based porous materials provide a sustainable and biocompatible alternative to inorganic systems, offering a programmable platform for biomimetic catalysis, molecular separation, and green manufacturing.