Effect of laser fluence and pulse overlapping on corrosion properties, cytocompatibility and osseointegration of Ti6Al4V Alloy

The surface properties of artificial implants are responsible for contact, primary fixation, intermediate bonding and future stability with the host tissue and their suitable alteration can improve functionality of the implants. Here, a picosecond pulsed laser was employed to alter the surface properties of a widely used biomaterial, Ti64. Three types of samples with variation in average surface roughness, wettability and presence of oxide layer were prepared by changing the laser fluence and pulse overlapping factor. The influence of change in surface properties on electrochemical behavior, bio-corrosion and cytocompatibility and ossiointegration of the sample were investigated. Comparative studies showed an improvement in anticorrosive behavior of Ti64 alloy after laser treatment that is confirmed from the open-circuit potential, Tafel analysis and impedance spectroscopy in simulated body fluid. Furthermore, the non-toxic nature of laser-treated surface was established and was confirmed from the cytotoxicity studies on U2OS osteosarcoma cells. Comparable number of cells with no changes in nuclear morphologies were found to be adhered on laser-treated samples. Growth of hydroxayaptite on all samples was monitored 25 days after their immersion in simulated body fluid. Along with improved osseointegration capability, the laser-treated sample at a fluence of 0.12 J/cm2 and 58