Study of Poloxamer 407-Based Hydrogels Containing Zinc Oxide Nanoparticles for 3D Printing Study of Poloxamer 407-Based Hydrogels Containing Zinc Oxide Nanoparticles for 3D Printing

This study aimed to develop and characterize thermoresponsive bioinks based on Poloxamer 407 (P407) at different concentrations (20%, 25%, and 30%), modified with polyvinylpyrrolidone (PVP K30 and K90, 0.5 and 1%), alginate (3.85%), and gelatin (3.85%), and incorporated with zinc oxide nanoparticles (ZnO-NPs). The formulations were evaluated in terms of rheological properties, 3D printing performance, and post-printing drying behavior. Rheological analysis showed that P407 hydrogels at 25% and 30% exhibited pseudoplastic and thixotropic behavior, suitable for 3D printing, whereas formulations with ≤ 20% behaved as Newtonian fluids and were excluded. Drying tests revealed that the addition of PVP reduced the volume loss rate by up to 35% after 72 hours compared to pure P407, while alginate and gelatin improved the preservation of the printed cylindrical shape and reduced cracking. The incorporation of ZnO-NPs further enhanced water retention and structural stability. These findings highlight the potential of P407-based bioinks (25–30%) combined with functional additives and ZnO-NPs for biomedical applications requiring structural stability and precise printing behavior.