ABSTRACT
Objective: To investigate the role of platelet derived growth factor receptor alpha (PDGFRα) on bidirectional differentiation of glioma-associated oncogene homolog 1-positive mesenchymal stem cells (Gli1+-MSC). Methods: Breeding double reporter transgenic mice ROSAmT/mG/Gli1-CreERt2/PDGFRαfl (Experimental group) and ROSAmT/mG/Gli1-CreERt2 (Control group), 20 mice in each of the two groups at four weeks of age were selected, MSC were isolated from the mouse aortic epithelium. After tamoxifen inducement, the two groups of Gli1+-MSC were screened by green fluorescent protein (GFP) labeling and flow cytometry sorting. PDGFRα was conditionally knocked out in the experimental group, and the control group Gli1+-MSC expressed PDGFRα normally. The two groups of Gli1+-MSC were subjected to adipogenic induction and fibrogenic induction, the Western blotting was performed to detect PDGFRα, adipocyte markers [perilipin and CCAAT/enhancer binding protein alpha (C/EBPα)] and fibrogenic markers [alpha smooth muscle actin (α-SMA) and fibroblast-specific protein 1 (FSP-1)] and semi-quantitative analysis was performed. The degree of cellular adipose differentiation after bidirectional induction of Gli1+-MSC in both groups was observed by oil red O staining and analyzed semi-quantitatively. Results: After tamoxifen induction, Gli1+-MSC could be accurately isolated from flow cytometry by GFP labeling. Via adipogenic differentiation, the expression of PDGFRα in the experimental group (0.017±0.002) was significantly lower than that in the control group (0.184±0.012) (t=25.48，P=0.002). The protein expressions of perilipin (3.138±0.414) and C/EBPα (3.565±0.289) were significantly higher than those in the control group (2.312±0.218 and 2.179±0.103, respectively) (t=6.21，P=0.025；t=6.69，P=0.022). Thus, the knock-out of PDGFRα enhanced the adipogenic differentiation ability of Gli1+-MSC. After fibrogenesis induction, the protein expressions of PDGFRα, α-SMA and FSP-1 in the experimental group (0.030±0.001, 0.932±0.177 and 0.276±0.020, respectively) were significantly lower than those in the control group (0.439±0.006, 1.352±0.170 and 0.835±0.097, respectively) (t=149.40, P<0.001; t=66.38,P<0.001; t=11.41,P<0.08). This suggested that the knock-out of PDGFRα significantly inhibited Gli1+-MSC differentiation toward fibroblasts. After bidirectional induction, significantly less adipocyte formation was seen in the control group and more in the experimental group. Quantitative analysis showed that the amount of oil red O staining in the experimental group (0.461±0.042) was significantly higher than that in the control group (0.017±0.007) after bidirectional induction (t=23.20, P<0.01). Conclusions: PDGFRα plays an important role in the regulation of bidirectional differentiation of vascular adventitial Gli1+-MSC.
ABSTRACT
The clinical success of dental implants can be improved by achieving optimum implant properties,such as their biomechanical and surface characteristics.Nano-structured coatings can play an important role in improving the implant surface.The purpose of the present study was to determine the most appropriate conditions for electrophoretic deposition (EPD) of nano-zirconia coatings on Ti-6Al-7Nb substrates and to evaluate the structural and biomechanical characteristics of these deposited coatings on the dental implants.EPD was used with different applied voltages and time periods to obtain a uniform layer of nano-zirconia on Ti-6Al-7Nb samples.The coated samples were weighed and the thickness of the product layer was measured.Surface analysis was performed by using optical microscopical examination,scanning electron microscope and X-ray diffraction phase analysis.For in vivo examination,48 screw-designed implants (24 uncoated and 24 nano-zirconia coated) were implanted in both tibiae of 12 white New Zealand rabbits and evaluated biomechanically after 4-and 12-week healing intervals.Results revealed that the use of different conditions for EPD affected the final coating film properties.Increasing the applied voltage and coating time period increased the deposited nano-zirconia film thickness and weight.By selecting the appropriate coating conditions,and analyzing scanning electron microscopical examination and XRD patterns,this technique could produce a thin and continuous nano-zirconia layer with a uniform thickness of the Ti-6Al-7Nb samples.Mechanically,the nano-zirconia-coated implants showed a highly statistically significant difference in removal torque values,while histologically these coated implants enhanced and promoted osseointegration after 4 and 12 weeks of healing,compared with the uncoated ones.In conclusion,EPD is an effective technique for providing a high quality nano-zirconia coating film on dental implant surfaces.Moreover,the osseointegration of these coated dental implants is improved compared with that of uncoated ones.
ABSTRACT
The clinical success of dental implants can be improved by achieving optimum implant properties,such as their biomechanical and surface characteristics.Nano-structured coatings can play an important role in improving the implant surface.The purpose of the present study was to determine the most appropriate conditions for electrophoretic deposition (EPD) of nano-zirconia coatings on Ti-6Al-7Nb substrates and to evaluate the structural and biomechanical characteristics of these deposited coatings on the dental implants.EPD was used with different applied voltages and time periods to obtain a uniform layer of nano-zirconia on Ti-6Al-7Nb samples.The coated samples were weighed and the thickness of the product layer was measured.Surface analysis was performed by using optical microscopical examination,scanning electron microscope and X-ray diffraction phase analysis.For in vivo examination,48 screw-designed implants (24 uncoated and 24 nano-zirconia coated) were implanted in both tibiae of 12 white New Zealand rabbits and evaluated biomechanically after 4-and 12-week healing intervals.Results revealed that the use of different conditions for EPD affected the final coating film properties.Increasing the applied voltage and coating time period increased the deposited nano-zirconia film thickness and weight.By selecting the appropriate coating conditions,and analyzing scanning electron microscopical examination and XRD patterns,this technique could produce a thin and continuous nano-zirconia layer with a uniform thickness of the Ti-6Al-7Nb samples.Mechanically,the nano-zirconia-coated implants showed a highly statistically significant difference in removal torque values,while histologically these coated implants enhanced and promoted osseointegration after 4 and 12 weeks of healing,compared with the uncoated ones.In conclusion,EPD is an effective technique for providing a high quality nano-zirconia coating film on dental implant surfaces.Moreover,the osseointegration of these coated dental implants is improved compared with that of uncoated ones.
ABSTRACT
The aim of this study was to investigate the cytotoxicity of modified nonequilibrium plasma with chlorhexidine digluconate (CHX) on human gingival fibroblasts (HGFs), and to evaluate the biosecurity of modified nonequilibrium plasma with 2% CHX as a new method of root canal treatment. Tissue samples taken from human gingiva were primarily cultured and passaged. Cells from passages 3-7 were used. HGFs were treated by modified nonequilibrium plasma with 2% CHX for 0 min (control group), 30 s, 1 min, 1.5 min, 3 min, 5 min, and 10 min, respectively, and then they were incubated for 0, 24, and 48 h. After that, cell counting kit-8 (CCK-8) assay was applied to analyze the cytotoxicity of modified nonequilibrium plasma with 2% CHX on HGFs. There was no significant difference between the 0 h group treated with the modified nonequilibrium plasma for 1 min and the control group (P>0.05). However, there were significant differences between all the other treated groups and the control group (P<0.05). When treated for 1.5 min or shorter, the cell viability was obviously increased; while treated for 3 min or longer, it was obviously reduced. Moreover, when successively cultured for 0, 24, and 48 h, cell viability was decreased at first and then increased in the 3-min-treated and 5-min-treated groups. The modified nonequilibrium plasma with 2% CHX was of no influence on cell viability in 1.5 min treatment, and it could be safely used on root canal treatment.
Subject(s)
Adolescent , Adult , Humans , Anti-Infective Agents, Local , Toxicity , Cell Survival , Cells, Cultured , Chlorhexidine , Toxicity , Fibroblasts , Gingiva , Cell Biology , Plasma , Chemistry , Root Canal Therapy , MethodsABSTRACT
The aim of this study was to investigate the cytotoxicity of modified nonequilibrium plasma with chlorhexidine digluconate (CHX) on human gingival fibroblasts (HGFs), and to evaluate the biosecurity of modified nonequilibrium plasma with 2% CHX as a new method of root canal treatment. Tissue samples taken from human gingiva were primarily cultured and passaged. Cells from passages 3-7 were used. HGFs were treated by modified nonequilibrium plasma with 2% CHX for 0 min (control group), 30 s, 1 min, 1.5 min, 3 min, 5 min, and 10 min, respectively, and then they were incubated for 0, 24, and 48 h. After that, cell counting kit-8 (CCK-8) assay was applied to analyze the cytotoxicity of modified nonequilibrium plasma with 2% CHX on HGFs. There was no significant difference between the 0 h group treated with the modified nonequilibrium plasma for 1 min and the control group (P>0.05). However, there were significant differences between all the other treated groups and the control group (P<0.05). When treated for 1.5 min or shorter, the cell viability was obviously increased; while treated for 3 min or longer, it was obviously reduced. Moreover, when successively cultured for 0, 24, and 48 h, cell viability was decreased at first and then increased in the 3-min-treated and 5-min-treated groups. The modified nonequilibrium plasma with 2% CHX was of no influence on cell viability in 1.5 min treatment, and it could be safely used on root canal treatment.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate in vivo gene delivery of Bio-Oss coated with adeno-associated virus-mediated human bone morphogenetic protein 7 (rAAV-BMP7/Bio-Oss) for bone regeneration around dental implants.</p><p><b>METHODS</b>In vitro rAAV-BMP7 were constructed and compounded with Bio-Oss. In 6 male New Zealand rabbits, two hydroxyapatite (HA) coated titanium dental implants were placed respectively to each animal in the bilateral tibia metaphysis. Before implantation, a standardized gap (8 mm in width, 4 mm in depth) was created between the implant surface and the surrounding bone walls. Rabbits were randomly divided into three groups (group A, B, C). Gaps of group A were filled with rAAV-BMP7/Bio-Oss (n = 4), gaps of group B were filled with Bio-Oss alone (n = 4), and gaps of group C were filled with nothing (n = 4). The rabbits were sacrificed at 4 and 8 weeks respectively, and the sclerous tissue slices obtained, then histology and histomorphometric analysis were conducted.</p><p><b>RESULTS</b>Histological and histomorphometric analysis revealed an enlarged bone-forming area in the bone defects of group A and B at 4 and 8 weeks after implantation. Greater bone-implant contact was achieved with rAAV-BMP7/Bio-Oss than with Bio-Oss alone and this difference was statistically significant (P < 0.05).</p><p><b>CONCLUSION</b>rAAV-BMP7/Bio-Oss can induce a stronger peri-implant bone reaction and larger new bone formation than Bio-Oss alone in the treatment of bone defects adjacent to titanium dental implants.</p>
Subject(s)
Animals , Humans , Male , Rabbits , Bone Morphogenetic Protein 7 , Bone Regeneration , Bone Substitutes , Bone and Bones , Dental Implantation, Endosseous , Dental Implants , Durapatite , Minerals , TitaniumABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of transforming growth factor-beta1 (TGF-beta1) gene therapy on bone defect and bone rarefaction around endosseous implant.</p><p><b>METHODS</b>The primary cultured bone marrow derived stroma cells (BMSCs) was transfected by plasmid pCDNA3.1(+) -TGF-beta1, and was adhered with polylactic-co-glycolic acid (PLGA) for constructing TGF-beta1 gene-modified artificial bone. The model of rats with placed titanium implants in the proximal metaphyses of the tibiae after ovariectomy was made. The TGF-beta1 gene-modified artificial bone (experimental group), BMSCs-PLGA compound artificial bone (control group) and nothing (blank control group) were placed in the bone defect around implant. The tibiae were examined by decalcified sections with immunohistochemical method and histological analysis methods at intervals of 4 and 8 weeks after implant surgery in order to detect the expression of TGF-beta1 in new bone adjacent to the implant and the healing of the bone defect around the implant.</p><p><b>RESULTS</b>The expression level of TGF-beta1 of experimental group was higher than that of control group and blank control group at the 4th week. The histological analysis indicated that the gene-modified artificial bone had stronger osetogenic potential than others.</p><p><b>CONCLUSION</b>TGF-beta1 gene-modified artificial bone promotes the repair of the bone defect around titanium implants in osteoporotic rats.</p>