Characterization of progenitor cells and stem cells from the periodontal ligament tissue derived from a single person

BackgroundPeriodontal ligament progenitor cells (PDLPs) and PDL stem cells (PDLSCs) are progenitor and stem cells that were isolated from PDL tissues using the outgrowth and single cell isolation methods respectively. The differences between PDLPs and PDLSCs characteristics could be observed from previous studies. However, these cells were obtained from different patients. This study was the first report to compare the characterization of PDLPs and PDLSCs from the same person. Material and MethodsThe characterization of PDLPs and PDLSCs includes flow cytometry analysis, cell proliferation assay and the assessment of the colony-forming unit fibroblast. The osteogenic differentiation was evaluated by alkaline phosphatase activity, biomineralization (alizarin red staining) and gene expression of osteogenic markers. The adipogenic differentiation was examined by Oil Red O staining and adipocyte-related gene expression. ResultsMesenchymal stem cell marker expression and colony-forming unit fibroblast analysis of PDLPs and PDLSCs were similar. However, PDLSCs grew faster than PDLPs on days 3 and 5 of the cell proliferation assay. Both PDLPs and PDLSCs could differentiate into osteoblast and adipocyte-like cells. However, the mineralization of PDLSCs was stronger than that of PDLPs. ConclusionsThe characteristics of undifferentiated PDL cells in our study were not significantly impacted by the isolation method. We assumed that both PDLPs and PDLSCs are valuable cell sources for periodontal regeneration. However, PDLSCs have a possible advantage for the regeneration of alveolar bone

Structural chemistry of oximes

Oximes (RR'C=N-OH) represent an important class of organic compounds with a wide range of practical applications, but a systematic examination of the structural chemistry of such compounds has so far not been carried out. Herein, we report a systematic analysis of intermolecular homomeric oxime•••oxime interactions, and identify hydrogen-bond patterns for four major categories of oximes (R' = -H, -CH[subscript 3], -NH[subscript 2], -CN), based on all available structural data in the CSD, complemented by six new relevant crystal structures. The structural behavior of oximes examined here, can be divided into four groups depending on which type of predominant oxime•••oxime interactions they present in the solid-state; (i) O-H•••N dimers (R[superscript 2][subscript 2](6)), (ii) O-H•••N catemers (C(3)), (iii) O-H•••O catemers (C(2)), and (iv) oximes in which the R' group accepts a hydrogen bond from the oxime moiety catemers (C(6)). The electronic and structural effects of the substituent (R') on the resulting assembly has been explored in detail in order to rationalize the connection between molecular structure and supramolecular assembly