Quartz-crystal microbalance-dissipation technique for the study of initial adsorption of fibronectin onto tresyl chloride-activated titanium.

The immobilization of cell-adhesive proteins onto titanium implants improves biological response at the implant-tissue interface. Previous studies demonstrated the easy and direct attachment of fibronectin onto titanium with the use of a 2,2,2-trifluoroethanesulfonyl chloride (tresyl chloride) activation technique. The present study investigated the initial adsorption behavior of fibronectin on tresyl chloride-activated titanium by the quartz-crystal microbalance-dissipation (QCM-D) technique. The crystal resonant frequency and the dissipation shift of the oscillator were simultaneously measured by the injection of fibronectin/phosphate-buffered saline solution (pH = 7.4). The tresyl chloride-activated titanium surface showed a faster and greater decrease in frequency than that of untreated titanium, indicating that a greater amount of fibronectin was adsorbed in the former case during a 120-min adsorption. The dissipation-frequency plots revealed that, during the initial stage of adsorption, the bond between fibronectin and tresyl chloride-activated titanium is stronger than that between fibronectin and untreated titanium. The QCM-D technique can provide new insights into the adsorption mechanism of fibronectin.