Highly porous three‐dimensional (3D) scaffolds can mimic the lobular structure of a human liver where hepatocytes are organized. However, 3D scaffolds with uniformly porous and oriented structures are challenging to fabricate without cross‐linking agents. Herein, this work presents a Pickering emulsion‐induced interface approach to construct aligned porous scaffolds for 3D cell cultures through the combined use of surface‐carboxylated cellulose nanofibers and chitosan nanofibers as stabilizers, and freezing/lyophilization to remove the oil phase. The obtained Pickering emulsions exhibit long‐term stability and their droplet sizes are tunable from 2.7 to 10.2 µm. Assembly at the oil–water interface can be modulated by controlling the NaCl dosage and oil phase proportion, resulting in porous foams with tunable porosity and versatile architectures as an in vitro alternative to the native liver microenvironment. The foams are noncytotoxic, confirmed using mouse fibroblast NIH/3T3 cells, and the cells grow both on the surface and in the internal structure of the foam. Notably, the 3D porous scaffolds are favorable microenvironments for the formation of human liver carcinoma HepG2 spheroidal cells, which exhibit liver‐like activity. This strategy based on Pickering emulsion templating provides a new avenue for constructing bioadaptive 3D scaffolds, specifically all‐biomass porous foams, for tissue engineering.

The intracellular uptake and interaction behavior of emulsion microparticles in liver cells critical to host defense and inflammation is significant to understanding their potential cytotoxicity and biomedical applications. In this study, the cell death responses of fibroblastic, hepatocyte, and Kupffer cells (KCs) induced by four types of emulsion particles that are stabilized by polysaccharide nanofibers (cellulose or chitin), an inorganic nanoparticle (β‐tricalcium phosphate), or surfactants are compared. Pickering emulsion (PE) microparticles stabilized by polysaccharide nanofibers or inorganic nanoparticles have a droplet size of 1–3 µm, while the surfactant‐stabilized emulsion has a diameter of ≈190 nm. Polysaccharide nanofiber‐stabilized PEs (PPEs) markedly induce lactate dehydrogenase release in all cell types. Additionally, characteristic pyroptotic cell death, which is accompanied by cell swelling, membrane blebbing, and caspase‐1 activation, occurs in hepatocytes and KCs. These PE microparticles are co‐cultured with lipopolysaccharide‐primed KCs associated with cytokine interleukin‐1β release, and the PPEs demonstrate biological activity as a mediator of the inflammation response. Well‐designed PPE microparticles induce pyroptosis of liver cells, which may provide new insight into regulating inflammation‐related diseases for designing potent anticancer drugs and vaccine adjuvants.