Biodegradable 3D‐Printed Elastic Scaffolds With Bioactivity and Electro‐Mechanical Coupling Promote Neuro‐Vascularization for Critical‐Size Bone Defect Regeneration

ABSTRACT

The intrinsic electrophysiological properties of native bone tissue promote bone healing, highlighting the significant role of piezoelectric biomaterials in neuro‐vascularized bone regeneration. However, challenges remain with existing piezoelectric biomaterials regarding biodegradability, bioactivity, and structural stability. In this study, a 3D‐printed elastic scaffold that uniquely integrates biodegradability, high bioactivity, and electro‐mechanical coupling was developed. The scaffold was fabricated by compounding piezoelectric whitlockite with an organic polymer matrix (polyvinyl alcohol/gelatin/sodium alginate). First, the mechanism underlying the enhancement of piezoelectric performance in whitlockite via annealing was elucidated, providing a theoretical foundation for optimizing the scaffold's piezoelectric properties. Next, through the design of a multi‐network composite ink system, stable dispersion and homogeneous compounding of whitlockite within the range of 20–80 wt.% were achieved, along with high‐fidelity 3D printing of the scaffolds. Furthermore, precise modulation of the whitlockite loading ratio enabled synergistic optimization of the scaffold's piezoelectric responsiveness, mechanical adaptability, and biodegradation rate. In vitro and in vivo experiments collectively validated that the scaffold promotes neurogenesis, angiogenesis, and osteogenic differentiation through the synergistic interplay between electro‐mechanical coupling effects and the release of bioactive ions. This scaffold holds significant clinical potential for the regenerative repair of critical‐size bone defects.