Laser surface texturing of Ti-cp and Ti6Al4V alloy for the improvement of fibroblast adhesion and alignment and the reduction of bacterial adhesion

Surface texturing is widely investigated for the modulation of the surface properties and biological response of implantable materials. Laser is a green technology for the obtainment of specific patterns without the employment of toxic chemicals. In the present research, a picosecond laser treatment was applied to commercially pure titanium and Ti6Al4V alloy for the obtainment of aligned grooves characterized by micrometric width and spacing but submicrometric depth to promote fibroblast alignment and discourage bacterial adhesion. Surface topography and roughness of laser-textured surfaces were characterized using confocal microscopy, contact profiler, and Scanning Electron Microscopy. Zeta potential titration curves and contact angle measurements were used for the investigation of surface charge and wettability, while X-Ray Diffraction was employed for crystallographic characterization. Finally, the biological response (fibroblast adhesion and alignment and bacterial adhesion) was assessed. Similar results were obtained on commercially pure Ti and Ti6Al4V. Grooves with the designed features were obtained (about 15 mu m spaced and 0.2 mu deep) and the treated surfaces had a complex micro- and nano-scale morphology which reduced wettability. No evident chemical modification occurred. The treated surfaces were biocompatible and grooves had a contact guidance effect on human fibroblasts. The obtained topography had anti-adhesive action on bacteria (Staphylococcus aureus).