Fabrication of antibacterial Zr-BMG biomimetic surfaces by femtosecond laser

Zirconium-based bulk metallic glasses (Zr-BMGs) are ideal materials for medical devices due to their unique amorphous structure, excellent wear resistance, good corrosion resistance, and high specific strength. The antibacterial performance of medical devices is critical in clinical treatments. Biomimetic structures are shown to have good antifouling behavior on the material's surface. In this study, six types of biomimetic structures (Shark skin-like, Rose leaf-like, Nepenthes-like, Rice leaves-like, Butterfly wing-like, and Bamboo leaf-like) were con-structed on Zirconium based bulk metallic glass by femtosecond laser with different laser energy intensities. The crystallization behavior and bacterial adhesion properties of biomimetic surfaces modified with femtosecond laser were explored. The results show that biomimetic surfaces have better antifouling characteristics than polished surfaces. While the antifouling properties of rice leaf-like structure and butterfly wing-like structure were the most effective. However, the bactericidal performance of the shark skin-like structure was the best. Furthermore, crystallization was observed on the Shark skin-like and Rose leaf-like surfaces processed with laser energy intensities greater than 2.38 J/mm2. Despite the surface crystallized layer, the substrate was still amorphous. Finally, based on the surface in vitro and in vivo cytotoxicity evaluation, the Nepenthes-like structure covered with disordered nano bulges showed the best balance between antifouling, bactericidal, and biocompatibility. The laser fabricated biomimetic structures can improve the antibacterial activity of Zr-BMG surgical tools and orthopedic implants, thus improving medical treatment quality.