Combined effects of melatonin and FGF-2 on mouse preosteoblast behavior within interconnected porous hydroxyapatite ceramics - in vitro analysis

Fabrication of water-dispersible and cell-stimulating calcium phosphate nanoparticles immobilizing basic fibroblast growth factor

Basic fibroblast growth factor (bFGF) is a therapeutic protein that can enhance angiogenesis, wound healing, and tissue regeneration; however, it is extremely unstable even under a normal physiological environment. Biocompatible calcium phosphate (CaP) nanoparticles (NPs) co-immobilizing bFGF, heparin, and ferucarbotran would be useful as a multifunctional delivery carrier of bFGF. In this study, such NPs were successfully fabricated by a coprecipitation process, using a labile supersaturated CaP solution containing bFGF, heparin, and ferucarbotran. The NPs showed relatively high negative zeta potential (-12 mV) because of the negatively charged heparin, which enabled their stable dispersion in water. The hydrodynamic diameter of the NPs was around 200 nm. Immunoreactive bFGF was released from the NPs in an acellular medium dose-dependently. The NPs promoted proliferation of baby hamster kidney fibroblasts (BHK-21 cells) and mouse osteoblastic MC3T3-E1 cells at a certain dose range, although they inhibited proliferation of rat pheochromocytoma (PC-12) cells. These results demonstrated that the effect of the NPs on cell proliferation was dependent on the cell type and dose, the details of which should be investigated in a future study.

The role of melatonin in bone regeneration: A review of involved signaling pathways

Increasing bone resorption followed by decreasing bone mineralization are hallmarks of bone degeneration, which mostly occurs in the elderly population and post-menopausal women. The use of mesenchymal stem cells (MSCs) has raised many promises in the field of bone regeneration due to their high osteoblastic differentiation capacity and easy availability from abundant sources. A variety of compounds, including growth factors, cytokines, and other internal factors, have been combined with MSCs to increase their osteoblastic differentiation capacity. One of these factors is melatonin, whose possible regulatory role in bone metabolism and formation has recently been suggested by many studies. Melatonin also is a potential signaling molecule and can affect many of the signaling pathways involved in MSCs osteoblastic differentiation, such as activation of PI3K/AKT, BMP/Smad, MAPK, NFkB, Nrf2/HO-1, Wnt, SIRT/SOD, PERK/ATF4. Furthermore, melatonin in combination with other components such as strontium, vitamin D3, and vitamin K2 has a synergistic effect on bone microstructure and improves bone mineral density (BMD). In this review article, we aim to summarize the regulatory mechanisms of melatonin in osteoblastic differentiation of MSCs and underling involved signaling pathways as well as the clinical potential of using melatonin in bone degenerative disorders.

The role of TGF-β1/Smad3 signaling pathway and oxidative stress in the inhibition of osteoblast mineralization by copper chloride

To explore the relationship of oxidative stress and TGF-β 1/Smad3 pathway in the inhibition of osteoblast mineralization by copper chloride (CuCl2), the osteoblasts were treated with CuCl2 (0, 50 μM, 100 μM, 150 μM CuCl2 5H2O) for 24 h. We found that Cu impaired the osteoblast structure, inhibited the glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities, alkaline phosphatase (ALP) content, mRNA expression of collagen I (COL-I), osteocalcin (OCN), insulin-like growth factor I (IGF-I), bone morphogenetic protein-2 (BMP-2), transforming growth factor β1 (TGF-β1) and core-binding factor α1 (Cbfα1), promoted the reactive oxygen species (ROS) production, inactivated the TGF-β1/Smad3 pathway. It indicates that the inactivated TGF-β1/Smad3 pathway leads to osteoblast impairment by CuCl2. It will contribute to clarify the influence of CuCl2 on the osteoblast mineralization.

Scaffold-based osteogenic dual delivery system with melatonin and BMP-2 releasing PLGA microparticles

The growing safety problems about the use of bone morphogenetic protein 2 (BMP-2) is one of the recent issues that was improved by using low doses of BMP-2 with the support of other osteoinductive agents and/or using appropriate carriers. The aim of the present study is to investigate the effect of scaffold-based dual release system including melatonin (MEL) and BMP-2 loaded polylactic-co-glycolic acid (PLGA) microparticles on the osteogenic activity of pre-osteoblastic MC3T3-E1 cells. MEL and BMP-2 loaded microparticles were prepared by double emulsion solvent evaporation method in the average diameters of ~2 µm and ~11 µm, respectively and loaded into chitosan/hydroxyapatite (HAp) scaffolds. In vitro MC3T3-E1 culture studies were carried out comparatively with blank scaffolds, single (BMP-2 or MEL) releasing groups and dual (BMP-2 and MEL) releasing group. Microscopic observations and hematoxylin/eosin staining showed enhanced number of cells and dense ECM in dual release group. The expressions of differentiation markers, Runt-related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP) and also mineralization were higher in dual release group than that of the other groups. Our findings showed that BMP-2 at low doses (~20 ng per scaffold) was sufficient in terms of osteogenic activity with controlled release systems where it was used in combination with MEL (~10 µg per scaffold).

The Role of Nutrition in Periodontal Health: An Update

Periodontal health is influenced by a number of factors such as oral hygiene, genetic and epigenetic factors, systemic health, and nutrition. Many studies have observed that a balanced diet has an essential role in maintaining periodontal health. Additionally, the influences of nutritional supplements and dietary components have been known to affect healing after periodontal surgery. Studies have attempted to find a correlation between tooth loss, periodontal health, and nutrition. Moreover, bone formation and periodontal regeneration are also affected by numerous vitamins, minerals, and trace elements. The aim of this review is to critically appraise the currently available data on diet and maintenance of periodontal health and periodontal healing. The effects of nutritional intervention studies to improve the quality of life and well-being of patients with periodontal disease have been discussed.