In one aspect, the present invention relates to a synthetic nanostructure. In one embodiment, the synthetic nanostructure has a top region substantially comprising titanate nanowires, a middle region substantially comprising titanate nanoparticles and titanate nanowires, and a bottom region substantially comprising titanium, wherein some of the titanate nanowires of the top region are extending into the middle region, wherein the middle region is between the top region and the bottom region, and wherein some of the titanate nanowires of the top region are substantially perpendicular to the bottom surface of the titanium substrate. At least some of the titanate nanowires in the top region form 3D macroporous scaffolds with interconnected macropores.