An in vivo method for measuring the adsorption of plasma proteins to titanium in humans

Abstract

A novel method of collecting in vivo plasma proteins of humans from osteotomies prepared during insertion of an oral implant is described. A rod containing a collecting portion with a predetermined surface is introduced into the osteomy, removed, and transferred for enzyme-linked immunosorbent assay analysis. Two experiments were used to examine the feasibility of the method. In the first, titanium (Ti) rods with different roughness were exposed for 10 min to the blood. Blasted and acid-etched surfaces adsorbed four times more and acid-etched surfaces adosorbed two times more plasma proteins as compared to machined surfaces. In the second experiment, blasted and acid-etched rods were wetted for 10 s prior to the insertion. The adsorption for fibronectin, albumin, fibrinogen, and IgG was enhanced significantly compared with nonwetted rods. These results are discussed in the light of previous methods used in studies on adsorption. Thus, use of the collecting instrument enables aspects of human plasma–implant interface to be studied in a more realistic manner.

Keywords:

• titanium
• plasma proteins
• wettability
• surface modification
• human study
• osseointegration

Acknowledgments

This work was supported by the internal research fund of the Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel. The titanium rods were kindly provided by Alpha-Bio Tec, Israel. The rods used in the experiment on wetting were kindly provided by MIS, Israel. The authors would like to thank Dr A. Vilensky and Dr K. Bilal for their help in the clinical phase.