A Hierarchical Hydrogel Impregnation Strategy Enables Brittle‐Failure‐Free 3D‐Printed Bioceramic Scaffolds

3D-printed bioceramic scaffolds offer great potential for bone tissue engineering (BTE) but their inherent brittleness and reduced mechanical properties at high porosities can easily result in catastrophic fractures. Herein, this study presents a hierarchical hydrogel impregnation strategy, incorporating poly(vinyl alcohol) (PVA) hydrogel into the macro- and micropores of bioceramic scaffolds and synergistically reinforcing it via freeze-casting assisted solution substitution (FASS) in a tannic acid (TA)-glycerol solution. By effectively mitigating catastrophic brittle failures, the hydrogel-impregnated scaffolds showcase three- and 100-fold enhancement in mechanical energy absorption under compression (5.05 MJ m