He's probably using Xilloc for the custom titanium implants.
I don't know why but having titanium implants doesn't ring very well for me, what if it leaches in your body and cause health problems? I didn't read any kind of published info on that, but that's just my gut feeling about it.
Titanium is used for hip replacements and other joint replacements and many kinds of implants. It becomes osseointegrated, that's why it's used. It also has excellent biocompatibility and isn't toxic....off the top of my head from my bioinorganic course I can't think of any enzymes that use titanium, So don't stress about it
From wikipedia -
Titanium is considered the most biocompatible of all metals due to its ability to withstand attack from bodily fluids, stay inert in the human body, be compatible with bone growth and stay strong and flexible during use. The materials ability to be resistant to body environments under stress, fatigue, and in crevice conditions is due to the protective oxide film that forms naturally in the presence of oxygen. The oxide film is highly adherent, insoluble, and chemically non transportable, preventing reaction from occurring.