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.