Macro-micron-nano-featured surface topography of Ti-6Al-4V alloy for biomedical applications

One of the critical issues in the development of novel metallic biomaterials is the design and fabrication of metallic scaffolds and implants with hierarchical structures mimicking human bones. In this work, selective laser melting (SLM) and electrochemical anodization were applied to fabricate dense Ti-6Al-4V components with macro-micron-nanoscale hierarchical surfaces. Scanning electron microscopy (SEM), 3D laser scanning microscopy (3D LSM), contact angle video system, fluorescence microscopy and spectrophotometer were used to investigate the properties of the samples. The results reveal that the SLMed post-anodization (SLM-TNT) exhibits enhanced or at least comparable wettability, protein adsorption and biological response of mesenchymal stem cells (MSCs) in comparison with the three reference configurations, i.e., the polished Ti-6Al-4V (PO-Ti64), the SLMed Ti-6Al-4V (SLM-Ti64) and the polished Ti-6Al-4V post-anodization (PO-TNT). The improved cytocompatibility of the samples after SLM and anodization should be mainly attributed to the nanoscale tubular features, while the macro-micron-scale structures only lead to slight preference for cell attachment.