Hydroxyapatite grafted carbon nanotubes and graphene nanosheets: promising bone implant materials

In the present study, hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and HA-graphene nanosheets were characterized using FT-IR, TGA, SEM and X-ray diffraction. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19). Total protein assays and western blot analysis of osteocalcin expression were used as indicators of cell proliferation and differentiation. Results indicated that hFOB 1.19 cells proliferate and differentiate well in treatment media containing CNTs-HA and graphene-HA. Both CNTs-HA and graphene-HA could be promising nanomaterials for use as scaffolds in bone tissue engineering.

Bacillus subtilis Modulated the Expression of Osteogenic Markers in a Human Osteoblast Cell Line

Several in vivo trials have previously demonstrated the beneficial effects of the administration of various probiotic forms on bone health. In this study, we explored the potency of two probiotics, Bacillus subtilis and Lactococcus lactis, alone or in combination with vitamin D (VD), to modulate the transcription of genes involved in the ossification process in a human osteoblast cell line. Genes that mark the "osteoblast proliferation phase", such as RUNX2, TGFB1, and ALPL, "extracellular matrix (ECM) maturation", such as SPP1 and SPARC, as well as "ECM mineralization", such as BGN, BGLAP, and DCN, were all highly expressed in osteoblasts treated with B. subtilis extract. The observed increase in the transcription of the ALPL mRNA was further in agreement with its protein levels as observed by Western blot and immunofluorescence. Therefore, this higher transcription and translation of alkaline phosphatase in osteoblasts treated with the B. subtilis extract, indicated its substantial osteogenic impact on human osteoblasts. Although both the probiotic extracts showed no osteogenic synergy with VD, treatment with B. subtilis alone could increase the ECM mineralization, outperforming the effects of L. lactis and even VD. Furthermore, these results supported the validity of employing probiotic extracts rather than live cells to investigate the effects of probiotics in the in vitro systems.

Selenomethionine, a Trace Element, Increases Osteoblastic Activity of hFOB 1.19 Cells (an In Vitro Study)

Osteoporosis and resulting fractures affect a significant group of people in the world. It has been shown in many studies that selenium has positive effects on bone metabolism. Based on this information, the aim of this study is to investigate whether bone differentiation will start in a shorter time by applying selenomethionine (SeMet) to hFOB cells.First, hFOB 1.19 cells were cultured. Safe doses of SeMet were determined by MTT and LDH tests. Ossification levels were determined by alizarin red staining and measurement of alkaline phosphatase enzyme levels. The results were analyzed with statistical tests.It was observed that SeMet increased cell viability at concentrations of 10, 25, 50, 100, and 200 µM in 24 h. At these concentrations, cell viability increased above the control, the viabilities were as follows: 109.4%, 104.9%, 104.3%, 103.15%, and 100.27%. High doses of SeMet significantly reduce cell viability. According to Alizarin red staining, SeMet increases the amount of calcium deposits in hFOB cells in a dose-dependent manner. In the experimental groups, the highest ALP enzyme was determined in the 7-day SeMet application. The most effective dose was measured as 15 µM.It was determined that SeMet, which is found as a trace element in living things in nature, increases the viability of hFOB cells, which are osteoblast cell precursors, and increases osteoblastic differentiation and osteoblastic activity in these cells. Our results are at a level that sheds light on an important problem in public health.