Method for immunolocalization of extracellular proteins in association with the implant-soft tissue interface

A method allowing immunolocalization of macromolecules surrounding biomaterial implants has been developed. Plugs of pure titanium were inserted into the abdominal wall of rats. One week after implantation plugs with adjacent tissue were gently fixed and cryoprotected before being rapidly frozen in LN2-cooled propane, followed by cryosubstitution, using methanol, and low temperature infiltration and UV curing of the methacrylate LR-Gold. Before sectioning, bulk metal was removed electrochemically, leaving the surface oxide intact, appearing in sections as a dense line in contact with the tissue. Postembedding immunolocalization for rat albumin, IgG, C3c, fibrinogen and fibronectin was performed at the light and electron microscopic levels. Our observations indicate that 1 wk after implant insertion, a network of fibrin and fibronectin decorates the tissue surface that faces the implant, but without any obvious concentration to the implant surface.