Abstract

A 60° reentrant zirconia scaffold best promotes bone and blood vessel formation. • Spider‑web‑like cell adhesion activates integrin and related kinase signaling. • Topology‑guided negative‑Poisson’s‑ratio design accelerates osseointegration. Negative Poisson’s ratio (NPR) structures, characterized by its unique compressive-contractive mechanical behavior, show great potential for bone implants, but their optimal configuration and osteogenic mechanisms in zirconia remain unclear. This study designs reentrant hexagonal zirconia scaffolds with internal angles of 60°, 45°, and 30°, and fabricates them using digital light processing (DLP) technology. In vitro experiments demonstrate that all NPR structures enhance the proliferation, adhesion, osteogenic differentiation, and paracrine angiogenic effects of rat bone marrow mesenchymal stem cells (rBMSCs) compared to solid control, with the 60/1.5 group being most effective. Further RNA-sequencing and pathway validation reveal the FAK-MAPK axis crucially mediates osteogenic differentiation induced by the concave topography. In vivo , the 60/1.5 scaffold implanted in rat femurs promotes faster new bone formation and more mature vascularization than the solid control. Collectively, these findings demonstrate that the internal angle is a critical geometric parameter governing the osteogenic performance of NPR structures. NPR zirconia scaffolds, specifically with the 60° internal angle, show great potential for enhancing early vascularized osseointegration, thereby providing a solid theoretical foundation and experimental support for the design of high-performance zirconia implants. Download: Download high-res image (116KB) Download: Download full-size image