3D printed biomimetic PEEK/HA scaffolds induce cranial bone regeneration.

The repair of critical-sized cranial defects resulting from trauma, congenital malformations, or surgery remains a significant clinical challenge. Polyetheretherketone (PEEK) is a commonly used material for cranial defect repair in clinical practice. However, its application is severely limited by drawbacks such as poor structural adaptability, bioinertness, and insufficient osseointegration, which significantly compromise clinical outcomes. In this study, we biomimicked the structure and composition of natural bone to fabricate a biomimetic PEEK/hydroxyapatite (HA) scaffold via a 3D printing strategy. This scaffold exhibits a stochastic lattice structure and mechanical properties similar to natural bone, capable of sustained release of calcium and phosphate ions. An in vitro co-culture study with bone marrow mesenchymal stem cells (BMSCs) confirmed that the biomimetic scaffold promotes cell proliferation and enhances the expression of osteogenesis-related proteins and genes. In a rat model with a critical-sized cranial defect (8 mm diameter), the biomimetic PEEK/HA scaffold demonstrated excellent capability in inducing bone regeneration and promoting osseointegration. This research provides a viable strategy for the repair and functional reconstruction of clinical critical-sized cranial defects.