Scanning tunneling microscopy for studying the biomaterial–biological tissue interface

Abstract

A scanning tunneling microscope (STM) coupled with a high resolution reflective optical microscope has been developed to investigate some aspects of the interface between metallic biomedical implants and living tissue. Initial biological measurements show that fibronectin (Fn), a glycoprotein which plays an important role in the promotion of cell and bacterial attachment, is well adsorbed on Ti and V substrates, but is not biologically active on V. STM images of the Ti oxide layer and of single and multiple Fn molecules deposited on mica and shadowed with a conductive layer are presented. These images demonstrate the capability of the STM for studying clinical implant surfaces with roughness larger than 1 μm as well as interface biochemical processes at the molecular level.

Surface analysis of human plasma fibronectin adsorbed to commercially pure titanium materials

“…Emch and coworkers have imaged fibronectin with scanning tunneling microscopy (STM) on mica shadowed with a thin platinum carbideconductive film. 15 Using scanning force microscopy (SFM) of fibronectin sprayed on mica and polymethylmethacrylate (PMMA), protein morphology was found to be influenced by substrate surface properties. 16 The application of this information to in vivo situations was limited because of the nonaqeous environment used for analysis.…”

Elucidation of Macromolecular Assemblies

“…Additionally organic molecules have been imaged as isolated molecules (71) and as liquid crystals (72,73). Note that these images were produced with various sample preparations including metal coating of the material (38,61,66,69), material transformed to its dry state (36,40,42,43,57,63,64,70), material deposited in solution via adsorption and electrochemical deposition (37,39,41,67), by freeze fracture replication (68), as well as, material assembled into Langmuir-Blodgett films (62).…”