A Fractal‐Like Hierarchical Bionic Scaffold for Osseointegration

Abstract Millions of patients each year are impacted by critical‐size bone tissue defects, the repair of which involves inflammation and the formation of new tissue. In this study, a fractal biomimetic design for a 3D‐printed scaffold that combined 3D printing with high‐energy plasma tantalum alloy fabrication, enabling easy production on an industrial scale is proposed. The fractal bionic design leverages the principles of fractal geometry, employing self‐affine patterns and random fractals to attain self‐affine surface design on 3D scaffolds. This approach aimed to emulate the fractal dimensions observed in natural bone structures closely. While the surface roughness of implants plays a critical role in restoration outcomes, this findings suggest that incorporating the surface fractal dimension may hold greater significance than mere roughness. A rat skull‐defect model is utilized to assess the osteogenic potential of the three scaffolds, and photoacoustic technology is first employed for long‐term, in situ monitoring of physiological signals during the bone repair process. Results from both cell and animal experiments demonstrated that fractal bionic scaffolds offer notable advantages over surface‐modified scaffolds and 3D‐printed scaffolds. This experimental results showed that the bionic scaffold group manifested a better bone‐promoting process.