3D printed bioceramic scaffolds with fully interconnected channel networks for enhanced vascularized bone regeneration.

Bioceramics have emerged as some of the most widely utilized and promising biomaterials for bone repair. The structural morphology of bioceramic scaffolds plays a critical role in determining their overall performance. Strategic morphological design and optimization have been demonstrated to substantially augment therapeutic outcomes. Herein, in this study, we present a strategy for fabricating β-tricalcium phosphate (β-TCP) bioceramic scaffolds featuring a dual-pore architecture comprising fully interconnected hollow channel networks and open macropores, achieved through extrusion-based 3D printing coupled with surface crosslinking. The manufacturing process enables simultaneous structural optimization and bioactive ion incorporation (e.g., Cu²⁺, Sr²⁺) during surface crosslinking. Comparative in vitro and in vivo evaluations revealed that the interconnected channel system significantly enhanced mass transport efficiency and cellular infiltration, leading to superior bone tissue ingrowth and vascularization compared to both non-channeled scaffolds and those with non-interconnected channels fabricated by coaxial 3D printing. This work establishes the following advances: integration of macropores with fully interconnected channel networks in bioceramic scaffolds using extrusion-based additive manufacturing, and demonstration of enhanced vascularized osteogenesis through optimized structural design. The findings provide insights into the rational design of advanced bioceramic scaffolds for functional bone regeneration.