In the present report, we have generated osteoblast-like cells derived from mouse induced-pluripotent stem (iPS) cells on PLGA with osteoinduction medium in vitro and in vivo. The cell culture period was 2 weeks. At 2 weeks, mRNA level of type I collagen was significantly higher than at 1 week. Osteocalcin mRNA level at 2 weeks was tendency to increase compared with at 1 week. And the cells cultured on PLGA were positive for immunofluorescent staining of osteocalcin and alizarin red S staining. The scaffold and osteogenic-like cells induced in vitro were implanted subcutaneously into SCID mice. In resected teratoma, hard tissues resembling bone were observed mixed with other tissues on the scaffold. The sum of these findings suggests that PLGA does not disturb the osteogenesis of iPS cells.

These results demonstrate that CO2 laser irradiation induces degeneration in the pulp tissue, which is then repaired by newly formed odontoblast-like cells.

BackgroundThe purpose of the present study was to examine the in vitro responses of ERM cells under the combination of centrifugal and compression forces, in terms of their expression of HSP70 mRNA.MethodsThe ERM cells were positive for CK19 indicating that they were derived from the odontogenic epithelium. Cultured ERM cells were applied centrifugal force and compressing force at one to three times as mechanical forces. After addition of forces, cells were observed using scanning electron microscope (SEM) and were measured expression of HSP70 mRNA by RT-PCR.ResultsSEM observations showed the cells were flattened immediately after the application of mechanical force, but nuclear protrusions recovered the same as the control 3 h later. A significantly higher expression of HSP70 mRNA was observed in ERM cells under mechanical force compared with the control, but it gradually decreased with time. No accumulation of HSP70 mRNA expression occurred with intermittent force. However, the expression of HSP70 mRNA with intermittent force repeated 3 times was significantly higher compared with intermittent force applied only once or twice.ConclusionsThese findings suggest that ERM cells express HSP70 mRNA in response to mechanical force, and that intermittent force maintains the level of HSP70 mRNA expression.

The effect of differing polystyrene substrate topographies on the osteogenic potential of the outgrowing cells (OGCs) formed from mouse‐induced pluripotent stem (iPS) cells (miPSCs)‐derived embryoid bodies (EBs) was investigated. Polystyrene substrates were sandblasted with 25, 50, and 150 μm aluminum oxide particles to obtain topographies with average Sa values of 0.6, 1.1, and 1.8 μm, respectively. 3D‐SEM was used to evaluate substrate's topographies. Examination was done by scanning electron microscopy (SEM), by immunocytofluorescence (ICF) analysis for vinculin, Runx2 and collagen type I, and by quantitative RT‐PCR (qRT‐PCR) analysis for Runx2 and collagen type I. SEM and ICF analyses revealed that surface roughness caused cells elongation (2, 6, 8, 10 times for the NT, 0.6 μm, 1.1 μm, and 1.8 μm, respectively). Vinculin staining demonstrated how the Sa value affected cellular attachment to the substrate. FA points were randomly distributed on flat surfaces, but rough surfaces resulted in more concentrated FA points on the podia of the cells (11.7, 25.2, 26.7, 16.6 vinculin spots per 20 μm2 for the NT, 0.6 μm, 1.1 μm, and 1.8 μm, respectively). qRT‐PCR revealed that Runx2 expression was highest on day 16 on surfaces with Sa of 0.6 μm and 1.1 μm. Collagen type I expression increased from day 0 to day 16, no significance was found among the groups. In conclusion, surface topography affects cell shape and expression of early osteogenic potential in OGC, particularly surfaces with Sa values of 0.6 μm and 1.1 μm which showed the highest concentration of FA points on podia. These findings could be utilized in the development of inner surface topographies of scaffolds used with iPSCs. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2288–2296, 2019.

Candida albicans, one of the main pathogens in the oral cavity, is involved in the development of oral candidiasis. Various components of tea, and especially polyphenols, are believed to be effective against the growth of yeast or bacteria. The purpose of this study was to investigate the effect of polyphenols in Mongolian herbal tea on growth of C. albicans. Tea extract was prepared from Mongolian herbal tea and diluted with distilled water (DW) at concentrations of 10, 20, 30, 40, or 50%. Distilled water was used as the control. Acidification of the medium was determined by measuring its pH; the presence of polyphenols by the Folin-Ciocalteau colorimetric method; and growth of C. albicans by absorbance at a wavelength of 630 nm at 0-, 6-, 12-, and 24-hr intervals. The pH of the medium was 5.2 to 5.27 in all experimental groups compared with 7.1 in the control group. Polyphenols were present in all experimental groups, and at significantly higher levels than in the control group. Growth of C. albicans showed a significant and timedependent increase in the control and all experimental groups. Growth of C. albicans in all the experimental groups was higher than that in the control group. These results suggest that Mongolian herbal tea promotes the growth of C. albicans, despite the presence of polyphenols.