Human ASPN(Asporin) ELISA Kit

Nitriding steel sample SACM 645 was nitrided by active screen plasma nitriding (ASPN) using a titanium screen to form simultaneously TiN coating/nitrogen-diffusion layer on the sample surface. ASPN experiments were carried out using a DC plasma-nitriding unit. The sample was placed on the sample stage in a floating potential and a cathodic potential. A titanium double screen was mounted on the cathodic stage around the sample stage. ASPN treatments at 0%-bias and 100%-bias were performed in a nitrogen-hydrogen atmosphere with 75% N-2 + 25% H-2 for 0-54 ks at 873 K under 100 Pa. After nitriding, the nitrided microstructure was examined with a scanning electron microscope, glow discharge optical emission spectroscopy and X-ray diffraction studies. In addition, the hardness of the surface and the cross-sections of the nitrided sample were measured using a Vickers microhardness tester under a 0.1-N load. The thickness of the TiN layer grew linearly with increasing nitriding time. In this case, the deposition rate of the TiN layer was 0.22 mu m/h. The nitrided layer formed by ASPN at 100%-bias consisted of a TiN compound layer followed by a nitrogen-diffusion layer. (C) 2012 Elsevier B.V. All rights reserved.

Human adult dental pulp stem cells (hDPSCs) are a unique precursor population isolated from postnatal dental pulp and have the ability to regenerate a reparative dentin-like complex. In this study, we investigated the role of Asporin in hDPSCs, which was identified as a matrix protein in our previous dentin proteomic analysis. We isolated a clonogenic, highly proliferative population of cells from adult human dental pulp. These isolated hDPSCs were confirmed by fluorescence activated cell sorting (FACS) using stem cell-specific markers and have shown multilineage differentiation potential. The localization of Asporin was identified by immunohistochemistry in the globular calcification region in the junction of predentin and dentin. The gene and protein expression levels of Asporin were enhanced at the early stage of and then reduced during the late stage of differentiation of hDPSCs in mineralization media. ASPN knock-down using a lentiviral system suppressed the mineralization of hDPSCs. These results suggest that ASPN plays positive roles in the mineralization of hDPSCs and predentin to dentin. J. Cell. Physiol. 226: 1676-1682, 2011. (C) 2010 Wiley-Liss, Inc.