Calcium phosphate deposition on titanium surfaces in the presence of fibronectin

Abstract

Titanium implants are known to nucleate spontaneously a calcium phosphate (apatite-like) layer when in contact with biological model fluids. The presence of proteins either in solution or pre-adsorbed on the titanium surface may influence the process of calcium phosphate deposition. The role of fibronectin, a protein known to promote cell adhesion in spite of its low concentration in biological fluids, was dissolved in Hanks' balanced salt solution (HBSS) and investigated. Several techniques of surface analysis, namely wettability, XPS, and SEM studies, were applied. The concentration of fibronectin in the HBSS solution was an important parameter in the process of calcium phosphate deposition. Concentrations as low as 0.01 mg/mL did not significantly affect the ionic precipitation; however, if the protein concentration was increased to 0.05 mg/mL, a value still far below the concentration in blood (0.2 mg/mL), the formation of a calcium phosphate layer was strongly inhibited. The influence of fibronectin pre-adsorbed on titanium surface also was investigated. It was found, as in the first case, that the extent of ionic precipitation that occurred during the immersion in HBSS depended on the protein concentration in the NaCl solution used to pre-immerse the titanium sample.

Enhanced cellular adhesion on titanium by silk functionalized with titanium binding and RGD peptides

“…A number of extracellular matrix proteins (e.g., fibronectin) and plasma proteins (e.g., fibrinogen and albumin) strongly interact with TiO 2 . These interactions are often mediated via weak associations, including ionic forces and hydrogen bonds, resulting in unstable, highly reversible protein adsorption to TiO 2 [10],[11]. However, the adherence of proteins on the surface of metallic materials largely relies on nonspecific hydrophobic interactions, which generally results in the destruction of the protein structure and inactivation of bound biomolecules.…”

The effect of fibronectin-coated implant on canine osseointegration

“…Biologically active molecules can be deposited with inorganic components and incorporated into the crystal lattice [19]. Biomimetic coating with fibronectin has been tested in previous studies [20-23]. It is believed that application of fibronectin to the implant surface can enhance the osseointegration of dental implants to the bone [20-23].…”

“…Biomimetic coating with fibronectin has been tested in previous studies [20-23]. It is believed that application of fibronectin to the implant surface can enhance the osseointegration of dental implants to the bone [20-23]. Fibronectin is one of the cell-adhesive proteins that can improve cell activity, initial cell attachment, and cell spreading, and it is actively involved in cytoskeletal reorganization and bone tissue formation, in part by regulating the survival of osteoblasts [24].…”

Electronic Properties ofTiO2Nanoparticles Films and the Effect on Apatite-Forming Ability

“…Fractures formed on TS + AT-I (Figure 8(e)) after one week of immersion resembled fractured apatite layers formed on TiO 2 coatings [46], α -CaSiO 3 ceramics [47], chemically treated titanium [48], and alkali- and heat-treated titanium [49]. The apatite layer formed on the TS + 8 nm and TS + 22 nm surfaces (Figures 8(b) and 8(c)) exhibited another type of fractures similar to those on apatite layers formed on titanium, first incubated in a fibronectin solution and thereafter in Hank's Buffer Saline Solution (HBSS) for one week [50]. The cracks or fractures have been suggested to be caused by drying shrinkage [40, 51] and have been observed to be larger and deeper with increasing immersion time [40, 51].…”