Journal of Oral Tissue Engineering

Fibronectin Adsorption by using 27M Hz Quartz-crystal Microbalance Technique


1Department of Dental Engineering, Tsurumi University School of Dental Medicine, Yokohama, Japan
2Center for Regenerative Medicine, Fukuoka Dental College, Fukuoka, Japan

J Oral Tissue Engin 2012;10(1):28-33

The quartz crystal microbalance (QCM) method can detect the adsorption amounts of proteins on biomaterials by a frequency shift of the oscillating quartz crystal. In the present study, we observed the adsorption behavior of fibronectin onto a gold surface by using 27 MHz QCM.
The QCM apparatus used was a 27-MHz AFFINIX QNm (Initium Co., Ltd, Tokyo, Japan) with 500 μL cells. The temperature was maintained at 25 ± 1°C and the solution in the cells was stirred during the measurements. Human plasma fibronectin was dissolved in phosphate-buffered saline (PBS) solution (pH 7.4) at a concentration of 200 μg/mL and 500 μg/mL. Each protein solution was injected into the PBS solution in the cells of the QCM apparatus. The frequency decrease was monitored and the amounts of fibronectin adsorbed onto the gold surface at 30 min after the injection were calculated by Sauerbrey's equation.
A slight frequency decrease was observed at the injection of fibronectin of 200 μg/mL, and greater degree of frequency decrease was monitored for fibronectin of 500 μg/mL. Significant differences in the adsorbed amounts were seen between 200 μg/mL and 500 μg/mL fibronectin. The adsorbed amounts of 500 μg/mL fibronectin was almost twice of 200 μg/mL fibronectin.
The QCM method was found to be a very powerful tool for monitoring the adsorption behavior of proteins on the material surface

Key words: : fibronectin, quartz crystal microbalance, protein adsorption