Study of the Biocompatibility of Surgical Implant Materials at the Atomic and Molecular Level Using Scanning Tunneling Microscopy

We have investigated some aspects of the interface between metallic biomedical implants and living tissue. To characterize this interface we have developed an STM coupled with a high resolution reflective optical microscope. The STM is used in connection with other microscopic techniques: TEM, SEM, and Auger spectroscopy. Initial biological measurements show that fibronectin (Fn), a glycoprotein which plays an important role in cell attachment and bacterial promotion, is attached on Ti and V substrates, but is not biologically active on V, a non-biocompatible substance. We present STM images of the Ti oxide layer and of single and multiple Fn molecules shadowed with a conductive layer.