Copper is a bad move. Seriously the industry's solution is not more metals. Ever heard of copper poisoning? I told you I developed a copper allergy just living in Salt Lake because of the copper mine.
They are trying to make a biodegradable implant that is printed in the surgery room. Titanium isnt biodegradable and would just lead to high levels of Ti or maybe even worse TiO2 in the bloodstream if it was.