Short-term evaluation of electromagnetic field pretreatment of adipose-derived stem cells to improve bone healing

An electromagnetic field is an effective stimulation tool because it promotes bone defect healing, albeit in an unknown way. Although electromagnetic fields are used for treatment after surgery, many patients prefer cell-based tissue regeneration procedures that do not require daily treatments. This study addressed the effects of an electromagnetic field on adipose-derived stem cells (ASCs) to investigate the feasibility of pretreatment to accelerate bone regeneration. After identifying a uniform electromagnetic field inside a solenoid coil, we observed that a 45Hz electromagnetic field induced osteogenic marker expression via bone morphogenetic protein, transforming growth factor , and Wnt signalling pathways based on microarray analyses. This electromagnetic field increased osteogenic gene expression, alkaline phosphate activity and nodule formation in vitro within 2weeks, indicating that this pretreatment may provide osteogenic potential to ASCs on three-dimensional (3D) ceramic scaffolds. This pretreatment effect of an electromagnetic field resulted in significantly better bone regeneration in a mouse calvarial defect model over 4weeks compared to that in the untreated group. This short-term evaluation showed that the electromagnetic field pretreatment may be a future therapeutic option for bone defect treatment. Copyright (c) 2012 John Wiley & Sons, Ltd.1142sciescopu

The Effect of Silicon Ion on Proliferation and Osteogenic Differentiation of Human ADSCs

Tissue engineering requires biopolymer scaffolds with compressive strength. Bioglass produces the compressive strength required of new scaffolds, and ionized Bioglass improves cell proliferation and differentiation. Ionized Bioglass contains phosphorous, sodium, calcium, and silicon ions, but the contributions of single ions or ion complexes to the cellular effects of Bioglass have not been determined. Here, we examined the effect or silicon on cell growth and differentiation. Culture medium containing 2, 4, 6, 8, and 10 mu M silicon ions was produced in a chemical neutralization reaction by mixing a sodium silicate solution and hydroxychloride, and human adipose-derived stromal cells (ADSCs) were cultured in the silicon-containing medium. Cell growth was followed for 9 days in culture, using a Cell Counting Kit-8 assay. Osteogenic differentiation was examined by alizarin red S staining and RT-PCR for osteogenic genes at 10, 20, and 30 days of culture. The proliferation of human ADSCs cultured in medium containing 2 or 4 mu M silicon was significantly greater than that of ADSCs in the control medium. Differentiation of human ADSCs was increased by supplementation of the differentiation medium with 2 mu M silicon. This work demonstrates that 2 mu M silicon accelerated proliferation and osteogenic differentiation of human ADSCs.X116sciescopuskciothe

Magnetic oxide formation at Al2O3/Co84Fe16 interface in magnetic tunnel junction

We investigated the interfacial status of ferromagnetic Co84Fe16/insulating barrier Al2O3 of the Al2O3-based magnetic tunnel junction (MTJ) using various x-ray scattering measurements. The results show formation of orthorhombic AlFeO3 magnetic nanoparticles at the interface, which are embedded in the Al2O3 cage. Their thickness and planner size vary with the plasma oxidation time. We also observed an interesting magnetic anomaly with a minimum magnetic coercivity near the AlFeO3 ferrimagnetic T-C, which is successfully explained in terms of the AlFeO3 nanoparticles and nanoscale CoFe grains with size distribution.X1122sciescopu