Design and Fabrication of Bioactive and Antibacterial LIPSS Surfaces on Titanium Alloy by Femtosecond Laser.

Abstract

A titanium alloy is widely used in implants for its excellent mechanical properties and corrosion resistance. However, the bonding strength between a titanium alloy and bone tissue is low, and the bacterial adhesion is easily triggered on the implant surface, which may cause the failure of implants. Therefore, surface modification is necessary to improve the biological activity and antibacterial properties. In this work, four different types of laser-induced periodic surface structure (LIPSS) surfaces are designed and fabricated on the TiNi alloy by a femtosecond laser according to the size of MC3T3-E1 mouse embryonic osteoblasts. The in vitro osteogenic activity of the LIPSS surface is investigated. It is found that the LIPSS helps improve the in vitro osteogenic activity, and bonelike apatite tends to deposit and distribute on the LIPSS. The biological activity and antibacterial activity of the LIPSS surface are evaluated through cell culture experiments and Escherichia coli culture experiments. It is demonstrated that the horizontal LIPSS sample with a width of 30 μm has the highest cell proliferation rate (142.5% after 1 day, 132.3% after 3 days) and a good antibacterial rate (50.2%). These results provide guidance for the application of the LIPSS in biocompatibility and antibacterial aspects.