Antibacterial performance of nanosecond laser irradiated zirconium-based
bulk metallic glass
Bulk metallic glass (BMG) have attracted considerable attention during
the last decades due to their excellent physical, chemical, and
biomedical properties. This report aims to investigate the relationship
between antibacterial performance, crystallization behavior and laser
ablation parameters of Zr-based bulk metallic glass (Zr-BMG) after
nanosecond laser irradiation. The surface morphology, crystallization
behavior, surface quality, binding energy and Cu/Ni release properties
were explored after laser irradiation. The formation of reactive oxygen
species following the immersion of Zr-BMG in phosphate-buffered saline
was evaluated using the 2’,7’-dichlorofluorescin diacetate method.
Staphylococcus aureus was selected to assess the antibacterial
performance of Zr-BMG and mouse osteoblasts were used to examine the in
vitro cytotoxicity. The results showed that at a laser energy intensity
lower than 0.08 J/mm2 the amorphous structure of Zr-BMG was retained
after the irradiation process. Furthermore, the laser irradiation
process considerably increased the antibacterial performance of Zr-BMG.
The Cu/Ni release rate, reactive oxygen species concentration, and
antibacterial properties were directly proportional to the laser energy
intensity. However, surfaces with a high antibacterial rate also showed
high cytotoxicity. The surface irradiated with 7 μJ ablation pulse and
200 mm/s irradiation speed showed a better balance between antibacterial
and cytotoxic properties with amorphous status.