Bone Abstracts

Titanium implants have been extensively used in dentistry as a replacement of absent dental elements. The biocompatibility of a material depends on cellular response in contact with a surface. The microarray technology is a tool to obtain an overview of the cell state in terms of large-scale transcriptional expression in different situations. Thus, the objective of this investigation was to evaluate the transcriptional profile of osteoblastic cells from human alveolar bone cultured on titanium surfaces, varying the etching parameters such as temperature and composition of H₂SO₄/H₂O₂ solution used. Polished discs were used as control. Human alveolar bone fragments were obtained from healthy donors, using the research protocols approved by the local research ethics committee. Cells were subcultured on sterilized titanium discs at a cell density of 2 ×10⁴ cells per disc in culture plates and divided into control (C), nanotexture (N), nano+submicrotexture (N+S) and rough microtexture (RM) groups. During the culture period, cells were incubated at 37°C in a humidified atmosphere of 5% CO₂ and 95% air and the medium was changed every other day. After 10 days, total RNA was extracted using Mirvana kit®. Oligo-arrays Agilent Human GE 4×44K and microRNA microarrays 8×15K were used and data analysis was performed by GeneSpring GX analysis software. Gene modulation was determined by ANOVA with a significant cut-off value of P≤0.05. Microarray analysis revealed 1.801 significantly regulated genes and 67 microRNAs. Differentially expressed genes were associated to osteogenesis, apoptosis and cell growth such as COL1A2, CASP4, E2F5 respectively. In the RM group, the great majority of microRNAs were expressed inversely when compared to the other experimental groups, for example hsa-miR-424-5p, hsa-miR-125a-5p and hsa-miR-125b-5p. These findings suggest that osteoblastic cells show different gene expression behavior when in contact with titanium surfaces modified by oxidative nanopatterning.