Protein Adsorption to Titanium and Zirconia Using a Quartz Crystal Microbalance Method

Protein adsorption onto titanium (Ti) or zirconia (ZrO₂) was evaluated using a 27 MHz quartz crystal microbalance (QCM). As proteins, fibronectin (Fn), a cell adhesive protein, and albumin (Alb), a cell adhesion-inhibiting protein, were evaluated. The Ti and ZrO₂ sensors for QCM were characterized by atomic force microscopy and electron probe microanalysis observation, measurement of contact angle against water, and surface roughness. The amounts of Fn and Alb adsorbed onto the Ti and ZrO₂ sensors and apparent reaction rate were obtained using QCM measurements. Ti sensor showed greater adsorption of Fn and Alb than the ZrO₂ sensor. In addition, amount of Fn adsorbed onto the Ti or ZrO₂ sensors was higher than that of Alb. The surface roughness and hydrophilicity of Ti or ZrO₂ may influence the adsorption of Fn or Alb. With regard to the adsorption rate, Alb adsorbed more rapidly than Fn onto Ti. Comparing Ti and ZrO₂, Alb adsorption rate to Ti was faster than that to ZrO₂. Fn adsorption will be effective for cell activities, but Alb adsorption will not. QCM method could simulate in vivo Fn and Alb adsorption to Ti or ZrO₂.