In vitro and in vivo evaluation of surface functionalization of titanium with H 2 O 2 hydrothermal treatment and FGF-2

• Published in: Journal of biomedical materials research. Part B, Applied biomaterials Vol. 111; no. 3; pp. 646 - 655
• Main Authors: Yoneyama, Yuya, Matsuno, Tomonori, Fujioka-Kobayashi, Masako, Satomi, Takafumi
• Format: Journal Article
• Language: English
• Published: United States 01.03.2023
• Subjects: Alloys; Animals; Bone and Bones; Fibroblast Growth Factor 2 - pharmacology; Mice; Rats; Surface Properties; Titanium - chemistry; Titanium - pharmacology; FGF-2; bone bioactivity; hydrothermal oxidation; surface functionalization; titanium implant
• ISSN: 1552-4973; 1552-4981
• DOI: 10.1002/jbm.b.35183

The goals of the study were to investigate the effects on bone bioactivity of a titanium dioxide layer formed by hydrothermal oxidation of a titanium surface with hydrogen peroxide (H O ) and loading with fibroblast growth factor-2 (FGF-2) in vitro and in vivo. Ti-6Al-4V discs were hydrothermally oxidized with H O and then loaded with FGF-2. After cytotoxicity testing, Ti-6Al-4V mini-implants were subjected to the same treatment, and their osteogenic potential was evaluated histologically in a rat model. H O hydrothermal oxidation resulted in a dense porous network structure and hydrophilic changes, which improved retention of FGF-2. Morphologically, the cell density was higher, cell elongation was more pronounced, and the cell adhesion area was significantly higher in FGF-2-loaded cells than in those without FGF-2. In a cell proliferation assay using mouse osteoblast-like cells, absorbance tended to increase over time, especially in the FGF-2 group after 7 and 14 days, and in a bone differentiation assay based on ALP activity, there was a significant increase in the FGF-2 group after 14 days. In the rat model, H O hydrothermal oxidation and FGF-2 loading both resulted in more laminar bone tissue in the bone marrow around the mini-implant. These results suggest that titanium surface functionalization by H O hydrothermal oxidation and FGF-2 may promote initial cell adhesion, proliferation, and osteodifferentiation, and enhance bone bioactivity. These effects all contribute to early bonding of an implant with the surrounding bone.