The controlled release pattern observed in Figure is consistent with release behavior from an ordered nanotubular structure. Typically at the initial stage, the PBS solution interacts with the nanoparticles at the surface, and due to a higher concentration gradient, there is a burst release. Subsequently, equilibrium concentration is established as the solution gradually infiltrates along the nanotube, and a constant controlled amount is observed due to the homogenous distribution of the silver nanoparticles and oxide in the nanotubular matrix. The toxicity of Ag ions to human cells is generally observed from above 1 mg/L 47 , the amount of Ag ions released from this system is between 10 µg/L to 4 µg/L; below the toxicity threshold. Furthermore, studies have shown that below 40 µg/L AgNp exhibits some favourable effects on promoting cell spreading . Therefore this approach shows good promise for incorporating into medical devices that can be used to achieve improved interaction with human cells while maintaining a long time antibacterial activity.