Osteon-mimetic laser-structured Ti-6Al-4V supports for guided stem cell growth

Implant surface topography plays an important role in determining cell responses, including attachment, proliferation, migration, and differentiation. With rapid developments in micro-and nano-fabrication methods, precisely controlled patterns can be generated on implant surfaces. Osteon-mimetic structures are of great interest as new surface designs on bone implants for creating optimal conditions for bone tissue growth. In this work, we used a laser ablation technique to create a biomimetic relief on Ti-6Al-4 V supports. The osteon-mimetic reliefs exhibited patterns of concentric lamellae-like rings of different width and periodicity. A distinctive feature of these reliefs is the presence of a highly porous nanocoating of titanium oxides, formed as a result of reverse deposition from the vapor-gas phase during ablation. Our investigation of the response of human mesenchymal stem cells revealed that the osteon-mimetic microrelief topography significantly influenced their adhesion, proliferation, and polarization. The presence of the nanocoating further impacted the number and localization of their focal adhesions. The outcomes of this work demonstrate an innovative direction towards the design of osteon-mimetic topographies on implantable materials. This work also holds the potential to identify optimal combinations of microrelief and nanocoating parameters to elicit specific cellular responses.