Engineering Emulgel-Based Inks for 3D Printing Scaffolds with Enhanced Porosity for Supporting Cell Proliferation

Highly porous hydrogel scaffolds are critical for advancing three-dimensional printing in tissue engineering. Interconnected porous networks facilitate nutrient diffusion, waste removal, and cell infiltration, necessary processes for tissue regeneration. Emulgel-based inks are developed using oil-in-water Pickering emulsions, in which mineral oil serves as a sacrificial porogen within a carboxymethyl cellulose (CMC)/Laponite matrix, with Laponite providing stabilization of the emulsion. Nine formulations are prepared by varying CMC (0.5-1.0 wt %) and mineral oil (10-20 wt %) concentrations at fixed Laponite (2 wt %). Rheological characterization confirms pronounced shear thinning, appropriate viscoelasticity, and rapid thixotropic recovery, establishing suitability for extrusion-based printing. Post-printing lyophilization and oil removal produce interconnected, homogeneous pore networks, as revealed by scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). Hydrated scaffolds exhibit compressive moduli of 20-30 kPa, overlapping with native soft tissue stiffness. Swelling and degradation analyses confirm structural stability under physiological conditions. Biological assessment using human dental pulp mesenchymal stromal cells (DPMSCs) identifies the 1.0 wt % CMC, Laponite, and 10 wt % oil formulation as optimal, supporting sustained cell proliferation over 28 days following lyophilization and pre-conditioning. This platform provides fabrication advances in 3D-printed hydrogel scaffolds, enhanced porosity, and mechanical properties for soft-tissue engineering and drug delivery applications.