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Zeng Y.,Chongqing Medical University | Zeng Y.,Chongqing key Laboratory of Oral Diseases and Biomedical science | Zeng Y.,Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education | Pei X.,University of Sichuan | And 7 more authors.
Surface and Coatings Technology

As novel nanomaterials, graphene and its derivations have been applied into hydroxyapatite as reinforcements for biomedical applications. However, graphene/hydroxyapatite composites serving as implant coating have rarely been studied. In this study, graphene oxide (GO)/hydroxyapatite (HA) composite coatings have been firstly fabricated by electrochemical deposition technique on titanium (Ti) substrate. Then, the microstructure, phase constituents, bonding strength and in vitro cellular responses of composite coatings were researched. Raman spectroscopy and transmission electron microscopy corroborated that graphene oxide was successfully incorporated into the composite coatings. Results revealed that addition of GO have enhanced both the crystallinity of deposited apatite particles and the bonding strength of the as-synthesized composite coatings. Moreover, in vitro cell culture assessment showed better biocompatibility of composite coatings compared with the pure HA coating and pure Ti substrate. These results suggested that GO/HA composite coatings might be a promising candidate in the field of biomaterials, especially for implant coatings. © 2015 Elsevier B.V. Source

Xie B.-W.,Chongqing Medical University | Zhou J.-P.,Chongqing Medical University | Wang X.-M.,Chongqing Medical University | Yu Y.,Chongqing Medical University | And 4 more authors.
Journal of Shanghai Jiaotong University (Medical Science)

Objective: To perform surface modification for clinical orthodontic stainless steel arch wires, compare surface components, surface patterns, mechanical properties, corrosion resistance, and antibacterial property between modified and unmodified stainless steel arch wires, and provide reference for the clinical application of stainless steel arch wires. Methods: Stainless steel arch wires with the size of 0.019 inch (0.48)×0.025 inch (0.64 mm) were used. Polydopamine was used as the medium and carboxymethyl chitosan (CMC) was covalently grafted on the surface of stainless steel arch wires. Surface components were analyzed and surface patterns were observed by energy dispersive X-ray analyzer and scanning electron microscope. Microhardness tester was used to test hardness of stainless steel arch wires. Electrochemical working station (CHI660C) was used to measure the corrosion resistance. WST reagent was used to detect the antibacterial property. Results: The surface of modified stainless steel arch wires contained C, N, O, Si, Cr, Mn, and Fe, while the surface of unmodified stainless steel arch wires only contained Si, Cr, Mn, and Fe. The difference in microhardness between modified and unmodified stainless steel arch wires was not statistically significant. The corrosion resistance and antibacterial property of modified stainless steel arch wires were greater as compared with unmodified stainless steel arch wires. Conclusion: The modification of orthodontic arch wires via polydopamine surface and grafted CMC can mitigate corrosion and inhibit the growth of bacteria without compromising the mechanical performance, so as to benefit the orthodontic application. © 2016, Editorial Department of Journal of Shanghai Second Medical University. All right reserved. Source

Xu X.,Chongqing Medical University | Xu X.,Chongqing key Laboratory of Oral Diseases and Biomedical science | Zhou J.,Chongqing Medical University | Zhou J.,Chongqing key Laboratory of Oral Diseases and Biomedical science | And 4 more authors.

Objective: To observe dynamic changes in root resorption repair, tooth movement relapse and alveolar bone microstructure following the application of orthodontic force. Materials and Methods: Forces of 20 g, 50 g or 100 g were delivered to the left maxillary firstmolars of fifteen 10- week-old rats for 14 days. Each rat was subjected tomicro-computed tomography scanning at 0, 3, 7, 10, 14, 28 and 42 days after force removal. The root resorption crater volume, tooth movement relapse and alveolar bone microarchitecture were measured at each time point. Results: From day 3 to day 14, the root resorption volume decreased significantly in each group. In the 20-g force group, the root resorption volume gradually stabilized after 14 days, whereas in the 50-g and 100-g force groups, it stabilized after 28 days. In all groups, toothmovement relapsed significantly from day 0 to day 14 and then remained stable. From day 3 to day 10, the 20-g group exhibited faster relapse than the 50-g and 100-g groups. In all groups, the structure model index and trabecular separation decreased slowly from day 0 to day 10 and eventually stabilized. Trabecular number increased slowly from day 0 to day 7 and then stabilized. Conclusions: The initial stage of root resorption repair did not change significantly and was followed by a dramatic repair period before stabilizing. The most serious tooth movement relapse occurred immediately after the appliance was removed, and then the tooth completely returned to the original position. © 2016 Xu et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

Wang Q.,Chongqing Medical University | Wang Q.,Chongqing key Laboratory of Oral Diseases and Biomedical science | Wang Q.,Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education | Ao Y.,Chongqing Medical University | And 3 more authors.
Oncology Reports

Previous studies have shown that the aberrant expression of period circadian clock 2 (Per2) is closely related to the occurrence and development of cancers,but the specific mechanism remains unclear. In the present study,we used shRNA to downregulate Per2 in oral squamous cell carcinoma (OSCC) Tca8113 cells,and then detected the alterations in cell cycle,cell proliferation and apoptosis by flow cytometric analysis and mRNA expression alterations in all the important genes in the cyclin/cyclin-dependent protein kinase (CDK)/cyclin-dependent kinase inhibitor (CKI) cell cycle network by RT-qPCR. We found that in the Tca8113 cells,after Per2 downregulation,the mRNA expression levels of cyclin A2,B1 and D1,CDK4,CDK6 and E2F1 were significantly increased (P<0.05),the mRNA expression levels of p53,p16 and p21 were significantly decreased (P<0.05),cell proliferation was significantly higher (P<0.05),apoptosis was significantly lower (P<0.05) and the number of cells in the G1/G0 phase was significantly decreased (P<0.05). The present study proves that in OSCC,clock gene Per2 plays an important role in cell cycle progression and the balance of cell proliferation and apoptosis by regulation of the cyclin/CDK/CKI cell cycle network. Further research on Per2 may provide a new effective molecular target for cancer treatments. Source

Pang L.,Chongqing Medical University | Pang L.,Chongqing Key Laboratory for Oral Diseases and Biomedical science | Zhao X.,Chongqing University | Liu W.,Chongqing Medical University | And 5 more authors.

Bear bile was used as a traditional medicine or tonic in East Asia, and ursodeoxycholic acid (UDCA) is the most important compound in bear bile. Further, synthetic UDCA is also used in modern medicine and nutrition; therefore, its further functional effects warrant research, in vitro methods could be used for the fundamental research of its anticancer effects. In this study, the apoptotic effects of UDCA in human oral squamous carcinoma HSC-3 cells through the activation of caspases were observed by the experimental methods of MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay, DAPI (4’,6-diamidino-2-phenylindole) staining, flow cytometry analysis, RT-PCR (reverse transcription-polymerase chain reaction) assay and Western blot assay after HSC-3 cells were treated by different concentrations of UDCA. With 0 to 400 μg/mL UDCA treatment, UDCA had strong growth inhibitory effects in HSC-3 cells, but had almost no effect in HOK normal oral cells. At concentrations of 100, 200 and 400 μg/mL, UDCA could induce apoptosis compared to untreated control HSC-3 cells. Treatment of 400 μg/mL UDCA could induce more apoptotic cancer cells than 100 and 200 μg/mL treatment; the sub-G1 DNA content of 400 μg/mL UDCA treated cancer cells was 41.3% versus 10.6% (100 μg/mL) and 22.4% (200 μg/mL). After different concentrations of UDCA treatment, the mRNA and protein expressions of caspase-3, caspase-8, caspase-9, Bax, Fas/FasL (Fas ligand), TRAIL (TNF-related apoptosis-inducing ligand), DR4 (death receptor 4) and DR5 (death receptor 5) were increased in HSC-3 cells, and mRNA and protein expressions of Bcl-2 (B-cell lymphoma 2), Bcl-xL (B-cell lymphoma-extra large), XIAP (X-linked inhibitor of apoptosis protein), cIAP-1 (cellular inhibitor of apoptosis 1), cIAP-2 (cellular inhibitor of apoptosis 2) and survival were decreased. Meanwhile, at the highest concentration of 400 μg/mL, caspase-3, caspase-8, caspase-9, Bax, Fas/FasL, TRAIL, DR4, DR5, and IκB-α expression levels were the highest, and Bcl-2, Bcl-xL, XIAP, cIAP-1, cIAP-2, survival, and NF-κB expression levels were the lowest. These results proved that UDCA could induce apoptosis of HSC-3 cancer cells through caspase activation, and the higher concentration of UDCA had stronger effects in vitro. UDCA might be a good nutrient for oral cancer prevention. © 2015 by the authors; licensee MDPI, Basel, Switzerland. Source

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