Abstract. Human mesenchymal stem cells have previously been isolated and characterized from the gingiva, and gingiva-derived stem cells have been applied for tissue engineering purposes. The present study was performed to generate size-controllable stem cell spheroids using concave microwells. Gingiva-derived stem cells were isolated, and the stem cells of 1x10 5 (group A) or 2x10 5 (group B) cells were seeded in polydimethylsiloxane-based, concave micromolds with 600 µm diameters. The morphology of the microspheres was viewed under an inverted microscope, and the changes in the diameter and cell viability were analyzed. The gingiva-derived stem cells formed spheroids in the concave microwells. The diameters of the spheroids were larger in group A compared to group B. No significant changes in shape or diameter were noted with increases in incubation time. Cell viability was higher in group B at each time point when compared with group A. Within the limits of the study, the size-controllable stem cell spheroids could be generated from gingival cells using microwells. The shape of the spheroids and their viability were clearly maintained during the experimental periods.

Lovastatin is a cholesterol-lowering agent that also has effects of cell proliferation and apoptosis. The present study was performed to evaluate the effects of lovastatin on the proliferation and osteogenic differentiation of three-dimensional cell spheroids formed from human gingiva-derived stem cells (GDSCs) using concave microwells. GDSCs were plated on polydimethylsiloxane-based concave micromolds and grown in the presence of lovastatin at concentrations of 0, 2 and 6 µM. The morphology of the cells was viewed under an inverted microscope, and cell viability was determined with Cell Counting kit-8 on days 2, 7 and 14. Alkaline phosphatase activity assays were performed to evaluate the osteogenic differentiation on days 2 and 8. Alizarin red-S staining was also used to assess the mineralization of the stem cell spheroids at day 14. The results confirmed that GDSCs formed spheroids in concave microwells. No significant changes were noted with longer incubation time, and no significant differences in cell viability were noted between the three lovastatin groups at each time point. Higher osteogenic differentiation was observed in the 2 µM group when compared with the control. Mineralized extracellular deposits were visible after Alizarin red-S staining, and higher mineralization was noted in the 2 and 6 µM lovastatin groups when compared with the 0 µM control. The relative mineralization values of the 0, 2 and 6 µM groups on day 14 were 39.0±9.6, 69.3±6.0 and 60.9±7.5, respectively. This study demonstrated that the application of lovastatin enhanced the osteogenic differentiation of cell spheroids formed from GDSCs. This suggests that combinations of lovastatin and stem cell spheroids may have the potential for use in tissue engineering.

Cimicifugae Rhizoma is a traditional herbal medicine used to treat various diseases in Korea, China and Japan. Cimicifugae Rhizoma is primarily derived from Komarov or Linnaeus. Cimicifugae Rhizoma has been used as an anti-inflammatory, analgesic and antipyretic remedy. The present study was performed to evaluate the extracts of Cimicifugae Rhizoma on the morphology and viability of human stem cells derived from gingiva. Stem cells derived from gingiva were grown in the presence of Cimicifugae Rhizoma at final concentrations that ranged from 0.001 to 1,000 µg/ml. The morphology of the cells was viewed under an inverted microscope and the analysis of cell proliferation was performed using a Cell Counting kit-8 (CCK-8) assay on days 1, 3, 5 and 7. Under an optical microscope, the control cells exhibited a spindle-shaped, fibroblast-like morphology. The shapes of the cells in the groups treated with 0.001, 0.01, 0.1, 1 and 10 µg/ml Cimicifugae Rhizoma were similar to the shapes in the control group. Significant alterations in morphology were noted in the 100 and 1,000 µg/ml groups when compared with the control group. The cells in the 100 and 1,000 µg/ml groups were rounder, and fewer cells were present. The cultures that were grown in the presence of Cimicifugae Rhizoma at a concentration of 0.001 µg/ml on day 1 had an increased CCK-8 value. The cultures grown in the presence of Cimicifugae Rhizoma at a concentration of 10 µg/ml on day 7 had a reduced CCK-8 value. Within the limits of this study, Cimicifugae Rhizoma influenced the viability of stem cells derived from the gingiva, and its direct application onto oral tissues may have adverse effects at high concentrations. The concentration and application time of Cimicifugae Rhizoma should be meticulously controlled to obtain optimal results.

No abstract

Cimicifugae Rhizoma, a herb with a long history of use in traditional Oriental medicine is reported to have anti-inflammatory, antioxidant, anti-complement and anticancer effects. The aim of the present study was to evaluate the effects of Cimicifugae Rhizoma extracts on the osteogenic and adipogenic differentiation of human stem cells derived from gingiva. Stem cells derived from gingiva were grown in the presence of Cimicifugae Rhizoma at final concentrations of 0.1, 1 and 10 µg/ml. Cell proliferation analyses were performed at day 15. For osteogenic differentiation experiments, the stem cells were cultured in osteogenic media containing β-glycerophosphate, ascorbic acid-2-phosphate and dexamethasone, and osteogenic differentiation was evaluated by analysis of osteocalcin expression at 21 days. For adipogenic differentiation experiments, the stem cells were grown in adipogenic induction medium, and the adipogenic differentiation was evaluated by analysis of adipocyte fatty acid-binding protein at day 14. The cultures grown in the presence of 0.1 µg/ml Cimicifugae Rhizoma showed a significant increase in cellular proliferation at day 15 compared with the control group. The relative osteogenic differentiation in the presence of Cimicifugae Rhizoma for the 0.1, 1 and 10 µg/ml groups was 171.5±13.7, 125.6±28.7 and 150.5±9.0, respectively, when that of the untreated control group on day 21 was considered to be 100%. The relative adipogenic differentiation at day 14 of the 0.1, 1 and 10 µg/ml groups in the presence of Cimicifugae Rhizoma was 97.5±15.0, 102.9±12.8 and 87.0±6.8%, respectively when that of the untreated control group on day 14 was considered to be 100%. Within the limits of this study, Cimicifugae Rhizoma increased the proliferation of stem cells derived from the gingiva, and low concentrations of Cimicifugae Rhizoma may increase the osteogenic differentiation of stem cells.