When a biomaterial is implanted into the body, blood proteins adsorb on its
surface and subsequently cells adhere via the protein adlayer. Thus, the
understanding of protein adsorption and conformational change on the
biomaterial surfaces is of great importance to control the biocompatibility
such as antithrombotic properties and cell adhesion behaviors. In this
study, we synthesized hydroxyapatite (HAp) and carbonate apatite (CAp) by a
wet method. Then we successfully fabricated the HAp and CAp sensors for
QCM-R by an electrophoretic deposition method. Adsorption behavior of
proteins on the bone substitute material can be monitored by using these
apatite sensors. Bovine serum albumin and fibrinogen were employed for the
model proteins, and monitored the adsorption behavior on the HAp, CAp and
reference gold (Au) sensors by the QCM-R technique. As a result, we revealed
that fibrinogen and bovine serum albumin adsorbs on the gold surface by
hydrophobic interaction, and adsorbs on the HAp and CAp surfaces mainly by
electrostatic force. Besides, we revealed that fibrinogen adsorbs on the Au
surface more rigid than on the HAp and CAp surfaces while bovine serum
albumin adsorbs on the HAp and CAp surface more rigidly than on the Au
surface.