Extrusion Bioprinting Device for Planar and Non-Planar Mammalian Cells and Bacterial Scaffolds Prototyping

This study developed a modified extrusion bioprinting platform capable of printing planar and non-planar hydrogel scaffolds with embedded bacteria or mammalian cells. By reengineering a commercial fused-deposition 3D printer (Wanhao Duplicator i3) with a custom hydrogel extrusion system and upgraded 32-bit control firmware, the team achieved precise deposition along curved trajectories. The system successfully printed alginate-gelatin scaffolds (planar and non-planar up to 15° inclination) with high geometric fidelity (88–98%) and maintained bacterial (Lactococcus lactis) and mammalian (HEPG2) cell viability (>70% after 72 h). This open-source design provides a low-cost, adaptable solution for curved biofabrication applications.