A comprehensive review on the printing efficiency, precision, and cell viability in 3D bioprinting

Three-dimensional (3D) bioprinting demonstrates significant potential for advancing regenerative medicine through precise fabrication of functional tissue constructs via controlled deposition of cells, biomaterials, and bioactive factors. However, balancing key parameters-printing efficiency, resolution, and cell viability-remains challenging for replicating native tissue complexity. This review comprehensively examines recent advancements in three prominent bioprinting modalities: inkjet, extrusion-based, and digital light processing (DLP). Analysis reveals inherent performance trade-offs among these technologies. Inkjet bioprinting achieves high resolution (10-80 μm) at moderate speeds but exhibits limited cell viability (74-85%). Extrusion-based methods enable higher fabrication rates (0.00785-62.83 mm³/s) with variable viability (40-90%) at reduced resolution (100-2000 μm). DLP offers superior efficiency (0.648-840 mm³/s) and ultra-high resolution (2-50 μm) with favorable viability (75-95%), although limitations persist regarding photoinitiator toxicity and light penetration depth. Critical examination identifies energy-induced cell damage as a significant factor, with shear stress and UV exposure representing key detrimental influences. Bioink properties also emerge as crucial determinants of printing outcomes. The review further integrates modeling approaches for extrusion-based bioprinting and discusses preliminary computational modeling attempts. Future directions should focus on developing low-viscosity cell-compatible bioinks, advancing hybrid printing strategies, and establishing predictive models to harmonize printing parameters with biological outcomes. Interdisciplinary collaboration remains essential to fully realize the clinical potential of bioprinted tissues and organoids.