Histological and TEM Observation of Subcutaneous Tissues Exposed to Particulate Copper, Nickel and Titanium

Abstract

The in vivo reaction against metal particles is still not well understood. We implanted particulate copper (Cu), nickel (Ni) and titanium (Ti) in subcutaneous tissues of the back of mice for 1 week and evaluated metal-implant-induced tissue reactions. In histological observations, Cu and Ni induced strong and moderate inflammation, respectively, while Ti caused little inflammation. Transmission electron microscope (TEM) observations clarified that a major inflammatory and body-defense cell was neutrophil against Cu and Ni, while no inflammatory cells were found around Ti. We speculated that tissue reactions against Cu and Ni were caused by eluted Cu and Ni ions, respectively, in the nearby tissues.