Interfacial Serum Protein Effect on Biological Apatite Growth

Abstract

Biological apatite (BAp) growth from a simulated body fluid on various substrate surfaces (gold (Au), titanium (Ti), and hydroxyapatite (HAp)) with and without preadsorption of fetal bovine serum protein (FBS) at the initial nucleation stage was investigated using a quartz crystal microbalance with the dissipation (QCM-D) technique. The protein composition in the FBS adlayer and viscoelastic property was elucidated by the Voigt-based viscoelastic model and antibody-binding analysis, respectively. The bare HAp effectively induced the BAp growth to increase the mass to 25.9 ± 3.2 μg cm–2 in 40 h; however, a slight increased mass of less than 1 μg cm–2 was detected on the Au and Ti, indicating the superior biocompatibility of the HAp surface. The FBS adsorption on the bare Au and Ti rapidly reached a plateau as compared to that on the HAp, and the adsorbed amount of the FBS on the HAp was approximately 2 times greater than those on the Au and Ti. The FBS adlayer on HAp showed the higher saturated ΔD/Δf value...