OBJECTIVES:Metformin (MF) could improve the osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) and bone regeneration under diabetes mellitus (T2DM) environment, however, its specific mechanism has not been elucidated. The aim of this study was to investigate whether MF inhibited oxidative stress and promoted osteogenic differentiation of T2DM rats BMMSCs (Tr-BMMSCs) through NRF2-GPX7 pathway. METHODS:BMMSCs were extracted from normal and diabetic rats. In vitro, the western blot analysis were first used to determine the effect of MF on the NRF2-GPX7 signaling pathway. Then, the levels of oxidative stress markers and ALP staining, alizarin red staining, immunofluorescence assay were performerd respectively to detect the role of NRF2-GPX7 pathway in the regulating effect of MF on the oxidative stress and osteogenic differentiation of Tr-BMMSCs. In vivo, the newly formed bone was evaluated by micro computed tomography, HE staining, Masson staining and immunohistochemistry through T2DM rat mandibular bone defect model. RESULTS:In vitro assays revealed that MF significantly promoted the expression of NRF2, NQO1, HO-1 and GPX7. The NRF2 pathway inhibitor (ML385) significantly inhibited the antioxidant and osteogenic promotion effects of MF on Tr-BMMSCs, while GPX7 overexpression effectively reversed the inhibitory effect of ML385. In vivo experiments showed that ML385 completely inhibited the combined promoting effects of MF and Tr-BMMSCs on the mandibular defect regeneration in T2DM rats. However, when MF was used in combination with GPX7 overexpressed Tr-BMMSCs, both new bone mass and OCN expression were significantly increased, indicating that GPX7 overexpression effectively reversed the osteogenesis inhibition of ML385 on Tr-BMMSCs. CONCLUSIONS:MF inhibits oxidative stress level and promots osteogenic differentiation of Tr-BMMSCs and the repair of mandible bone defects of T2DM rats through NRF2-GPX7 pathway.

This randomized clinical trial aimed to compare volumetric changes and histological characteristics of new bone in extraction sockets grafted with Bio-Oss (R) or THE Graft (R). Furthermore, it sought to further assess the quality and quantity of bone regeneration at 3- and 6-month intervals. Thirty-two patients requiring single-tooth extraction (excluding third molars) and ridge preservation in preparation for subsequent implant placement were randomized to receive either graft material (Bio-Oss (R) or THE Graft (R)) covered by a collagen membrane. At 3 months, BV/TV was higher in the DBBM groups than in the DPBM groups, while mineralized bone proportions were similar between groups. By 6 months, BV/TV remained significantly higher in DPBM groups than in the DBBM groups, and a higher proportion of mineralized bone was observed in the DPBM groups. Both groups showed increasing BV/TV and mineralized bone over time. In conclusion, both Bio-Oss (R) and THE Graft (R) effectively promoted socket bone regeneration, with healing time influencing bone formation. Long-term results suggest THE Graft (R) may enhance mineralized bone percentage more than Bio-Oss (R).

Aim or purpose: The primary objective of this randomized clinical trial was to compare the volumetric changes and the histological characteristics of newly formed bone in extraction sockets grafted with deproteinized bovine bone mineral (DBBM; Bio-Oss®) or de-mineralized porcine bone matrix (DPBM; THE Graft®). Additionally, the study aimed to assess the quality and quantity of bone regeneration at two specific time intervals (3 and 6 months) following grafting. Materials and methods: Thirty-two eligible patients requiring single-tooth extraction (excluding third molars) in the maxilla or mandible were enrolled in this study. Post-extraction cone beam computed tomography (CBCT) scans were performed, and sockets were filled with either DBBM or DPBM, covered with a collagen membrane. Participants were randomized into two groups: DBBM (n=16) and DPBM (n=16). After 3 or 6 months, 32 bone core specimens (8 per group/time point) were harvested for micro-computed tomography (μCT) and histological analysis. Results: Micro-CT analysis revealed no significant differences in newly formed bone volume fraction between groups (P˃.05). Both grafting materials promoted substantial bone regeneration; however, the DPBM group exhibited higher mineralized bone proportions within the defect area. Histological analysis of biopsies collected during implant placement demonstrates progressive increase in new bone formation over time in both groups. Conclusions: Both DBBM and DPBM effectively promote bone regeneration in extraction sockets. Healing duration significantly affects tissue composition in post-extraction sites, with DPBM yielding higher mineralized bone proportions compared to DBBM.

Objectives: High glucose (HG)-induced oxidative stress affects implant osseointegration through various pathways. Oxidative stress is widely recognized to suppress the Wnt/β-catenin signaling pathway, thereby impairing bone metabolism and homeostasis. However, there are few reports on whether excessive reactive oxygen species (ROS) influence osteogenic differentiation of stem cells via the noncanonical Wnt/calmodulin-dependent protein kinase II (CaMK II) pathway. An investigation of the mechanism by which ROS/CaMK II/β-catenin signaling axis influences the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) on titanium surfaces is being carried out in this investigation. Materials and Methods: In this study, titanium plates were specially treated to simulate implant surfaces. An osteogenic medium containing HG was used to cultivate BMSCs on titanium surfaces. The effects of excessive ROS induced by HG on the osteogenic differentiation of BMSCs, as well as on the expression of β-catenin and CaMK II, were examined using methods such as alkaline phosphatase (ALP) activity assay, quantitative real-time PCR (qRT-PCR), and immunofluorescence staining. Additionally, the effects of the Wnt/β-catenin and Wnt/CaMK II pathways on the osteogenesis of BMSCs on the titanium surface were observed by separately adding activators or inhibitors of β-catenin and CaMK II. Results: Excessive ROS induced by HG inhibited osteogenic differentiation. In a HG environment, β-catenin expression decreased, while CaMK II expression increased. Moreover, we observed that activation of the Wnt/β-catenin pathway promoted osteogenesis, whereas activation of the Wnt/CaMK II pathway inhibited it. Conclusions: In summary, BMSC osteogenesis on titanium surfaces is suppressed by HG-induced oxidative stress via the ROS/CaMK II/β-catenin signaling axis, which may subsequently impair implant osseointegration.

PURPOSE:The purpose of this study was to determine whether metformin (MF) could alleviate the expresssion of reactive oxygen species (ROS) and improve the osteogenic ability of bone marrow mesenchymal stem cells derived from diabetic rats (drBMSCs) in vitro, and to evaluate the effect of MF on the ectopic osteogenesis of drBMSCs in a nude mouse model in vivo.METHODS:BMSCs were extracted from normal and diabetic rats. In vitro, a cell viability assay (Cell Counting Kit-8), tests of alkaline phosphatase (ALP) activity, and western blot analysis were first used to determine the cell proliferation and osteogenic differentiation of drBMSCs that were subjected to treatment with different concentrations of MF (0, 50, 100, 200, 500 μM). The cells were then divided into 5 groups: (1) normal rat BMSCs (the BMSCs derived from normal rats group), (2) the drBMSCs group, (3) the drBMSCs + Mito-TEMPO (10 μM, ROS scavenger) group, (4) the drBMSCs + MF (200 μM) group, and (5) the drBMSCs + MF (200 μM) + H2O2 (50 μM, ROS activator) group. Intracellular ROS detection, a senescence-associated β-galactosidase assay, ALP staining, alizarin red staining, western blotting, and immunofluorescence assays were performed to determine the effects of MF on oxidative stress and osteogenic differentiation in drBMSCs. In vivo, the effect of MF on the ectopic osteogenesis of drBMSCs was evaluated in a nude mouse model.RESULTS:MF effectively reduced ROS levels in drBMSCs. The cell proliferation, ALP activity, mineral deposition, and osteogenic-related protein expression of drBMSCs were demonstrably higher in the MF-treated group than in the non-MF-treated group. H2O2 inhibited the effects of MF. In addition, ectopic osteogenesis was significantly increased in drBMSCs treated with MF.CONCLUSIONS:MF promoted the proliferation and osteogenic differentiation of drBMSCs by inhibiting the oxidative stress induced by diabetes and enhenced the ectopic bone formation of drBMSCs in nude mice.

2023年6月3日至4日,由白求恩精神研究会口腔医学分会、烟台市科学技术协会、滨州医学院及其附属烟台口腔医院主办的"第一届国产口腔种植体材料研发高峰论坛"在山东烟台成功举行!秉承"创新、引领、共赢"的会议精神,本次高峰论坛分别就国产口腔种植体企业高峰论坛、基础研究论坛、国产口腔种植体临床应用论坛3个主题,分享了20余个精彩的学术演讲,吸引了五百余人线下参会.

Background Concentrated growth factor (CGF) is a third-generation platelet concentrate product; the major source of growth factors in CGF is its extract; however, there are few studies on the overall effects of the extract of CGF (CGF-e). The aim of this study was to investigate the effect and mechanism of CGF-e on MC3T3-E1 cells in vitro and to explore the effect of combination of CGF-e and bone collagen (Bio-Oss Collagen, Geistlich, Switzerland) for bone formation in cranial defect model of rats in vivo. Methods The cell proliferation, ALP activity, mineral deposition, osteogenic-related gene, and protein expression were evaluated in vitro; the newly formed bone was evaluated by histological and immunohistochemical analysis through critical-sized cranial defect rat model in vivo. Results The cell proliferation, ALP activity, mineral deposition, osteogenic-related gene, and protein expression of CGF-e group were significantly increased compared with the control group. In addition, there was significantly more newly formed bone in the CGF-e + bone collagen group, compared to the blank control group and bone collagen only group. Conclusions CGF-e activated the PI3K/AKT signaling pathway to enhance osteogenic differentiation and mineralization of MC3T3-E1 cells and promoted the bone formation of rat cranial defect model.

INTRODUCTION The aim of this study is to investigate the effects of Concentrate Growth Factors Extract (CGF-e) on the proliferation and osteogenic differentiation of MC3T3-E1 cells under high glucose condition. MATERIALS AND METHODS MC3T3-E1 cells were divided into 4 groups including normal glucose (5.5-mM) group (control), high glucose (25.5-mM) group, normal glucose + CGF-e group, and high glucose + CGF-e group. The proliferation, osteogenic differentiation and mineralization of osteoblasts were evaluated, respectively, by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, cytoskeleton analysis, alkaline phosphatase activity assay, alizarin red staining, and real-time polymerase chain reaction. Western blots analysis was used to explore the role of PI3K/Akt pathway. RESULTS The viability, osteogenic differentiation, and mineralization of MC3T3-E1 cells were significantly decreased by high glucose. All observed osteogenic dysfunction were inhibited by CGF-e. Moreover, the PI3K/Akt pathway was activated by CGF-e. CONCLUSIONS It was concluded that the soluble factors released by CGF could significantly attenuate high glucose-mediated MC3T3-E1 cells osteogenic dysfunction through the PI3K/Akt pathway.

目的:总结六手操作技术在全口种植即刻修复中的优势,寻求最佳的护理配合方式.方法:全口无牙颌患者20例随机分为对照组(C)和实验组(P),分别采用四手操作和六手操作配合进行全口种植术后的即刻修复.通过操作时间,患者满意度,细菌检测及修复体表面菌斑指数来对两组进行比较.结果:P组的修复操作时间,细菌检测及修复体表面菌斑指数均显著少于C组(P＜0.05);且P组的患者满意度要显著高于C组(P＜0.05).结论:六手操作护理配合较四手操作更能够严格执行无菌操作,缩短治疗时间,提高工作效率,提高患者满意度和依从性,适合用于全口即刻修复的护理配合.

目的 观察高压氧对高浓度葡萄糖状态下MG-63细胞增殖和成骨分化的影响.方法 实验根据不同葡萄糖浓度及是否行高压氧分为四组:(1)5.5 mM(对照组);(2)25.5 mM(高糖组);(3)5.5mM+高压氧;(4)25.5mM+高压氧.分别检测细胞增殖、ALP活性以及成骨基因的表达.结果 高糖组的细胞增殖、ALP活性、成骨基因及P-AKT的表达均显著低于对照组(P<0.05);行高压氧处理后,各项指标均显著增高(P<0.05).结论 高压氧能抑制高糖对MG-63细胞增殖分化的不利影响.

目的:观察高压氧治疗对高糖状态下MC3T3-E1细胞增殖和成骨分化的影响.方法:根据细胞培养基的葡萄糖浓度以及是否进行高压氧处理将细胞随机分为四组: 1) 5.5mM正常浓度组; 2) 25.5mM高糖组; 3) 5.5mM+高压氧组; 4) 25.5mM+高压氧组.甲基噻唑基四唑(MTT)法测定1天, 3天的细胞增殖;碱性磷酸酶(ALP)活性检测3天, 7天的细胞分化情况;荧光实时定量PCR测定Run mRNA和OCN mRNA基因分别在3天、 7天的表达.结果: 25.5mM高糖组的MC3T3-E1细胞的增殖、 ALP活性以及成骨基因表达均显著低于5.5mM正常浓度组(P<0.05); 25.5mM+高压氧组的MC3T3-E1细胞的增殖及成骨分化较25.5mM高糖组显著提高(P<0.05).结论:高压氧能显著改善高糖对MC3T3-E1细胞的增殖及成骨分化的抑制作用.

The spindle and kinetochore-associated complex subunit 1(SKA1) is a newly discovered gene, which has been associated with mitosis and tumorigenesis. However, its role insalivary adenoid cystic carcinoma (SACC) is still unknown, and the invasive and metastatic mechanism in SACC is still unclear. To explore the molecular mechanism of SKA1 in the process of malignant proliferation and metastasis in adenoid cystic cancer (ACC) cells, we employed lentivirus-mediated short hairpin RNA to knockdown SKA1 in SACC-83 cells. The results demonstrated that the lentivirus-mediated shRNA-targeting SKA1 lead to a significant down-regulation of SKA1 expression. Knockdown of SKA1 inhibited cell proliferation, cell invasion, migration and the cell cycle arrest. Furthermore, knockdown of SKA1 reduced the Ndc80, CDK4, Cyclin D1, Cyclin E1, Cyclin B1 and matrix metalloproteinase-9 (MMP-9) protein expression, but increased the p27 protein expression. These findings indicated that SKA1 might be a promising target for cancer gene therapy in human ACC.

Purpose:The aim of the present study was to mimic the hierarchical structure of bone tissues by simple sandblasting/acid-etching and anodization to investigate the effects of such surface characteristics on proliferation and differentiation of osteoblasts in high glucose concentrations. By the way, the effects of high glucose levels on osteoblast functions were tested.Methods:MC3T3-E1 cells cultured on sand-blasted and acid-etched (SLA) surface and nano-modified SLA (NMSLA) surface were subjected to normal serum (NS) and diabetic serum (DS), respectively. The surface characteristics were evaluated by scanning electron microscopy. Cell proliferation was assessed using MTT assay. The levels of alkaline phosphatase (ALP) activity and mineralization were measured and compared. Real-time polymerase chain reaction was applied to detect the expression levels of osteogenic genes.Results:NMSLA significantly increased cell proliferation at time points ranging from 3 to 7 days under both serums. Cells cultured on NMSLA surfaces displayed significantly higher ALP activities and mineralization. The expression levels of Runx2 (indicates runt-related protein 2), collagen I (COL1), and osteocalcin (OCN) were notably increased on NMSLA surface compared with SLA surface. Moreover, we found that high glucose increased osteoblast proliferation but decreased differentiation of osteoblast slightly.Conclusion:The hierarchical micro/nano-structured titanium surface has a favorable biocompatibility on simultaneously improving osteoblast proliferation and differentiation in diabetic serum.

Background/Aims: Patients with diabetes mellitus have a higher risk of dental implant failure. One major cause is high-glucose induced oxidative stress. Alpha-lipoic acid (ALA), a naturally occurring compound and dietary supplement, has been established as a potent antioxidant that is a strong scavenger of free radicals. However, few studies have yet investigated the effect of ALA on osteogenic differentiation of osteoblasts cultured with high glucose medium. The aim of this study is to investigate the effects of ALA on the osteoblastic differentiation in MC3T3-E1 cells under high glucose condition. Methods: MC3T3-E1 cells were divided into 4 groups including normal glucose (5.5 mM) group (control), high glucose (25.5 mM) group, high glucose + 0.1 mM ALA group, and high glucose + 0.2 mM ALA group. The proliferation, osteogenic differentiation and mineralization of cells were evaluated by MTT assay, alkaline phosphatase (ALP) activity assay, alizarin red staining and real time-polymerase chain reaction. High-glucose induced oxidative damage was also assessed by the production of reactive oxygen species (ROS) and superoxide dismutase (SOD). Western blots were performed to examine the role of PI3K/Akt pathway. Results: The proliferation, osteogenic differentiation and mineralization of MC3T3-E1 cells were significantly decreased by the ROS induced by high-glucose. All observed oxidative damage and osteogenic dysfunction induced were inhibited by ALA. Moreover, the PI3K/Akt pathway was activated by ALA. Conclusions: We demonstrate that ALA may attenuate high-glucose mediated MC3T3-E1 cells dysfunction through antioxidant effect and modulation of PI3K/Akt pathway.

Objective:To evaluate the effect of concentrate growth factor extract(CGFe)on the proliferation and differentiation of MC3T3-E1 osteoblasts.Methods:MC3T3-1 cells were cultured with and without CGFe respectively.At 1 ,3,5 d of culture the pro-liferation of the cells was detected by MTT assay,the activity of alkaline phosphatase (ALP)of the cells was examined by ALP kit;at 1 4,21 d of culture the calcium nodus formation was observed by Alizarin red staining;RUNX2 and OSX expression was quantified by real-time PCR.Results:With the extension of culture time,the proliferation,ALP activity,the calcium nodus and the level of RUNX2 and OSX mRNA of the experimental group were increased more than those of the control group.Conclusion:CGFe may pro-mote the proliferation and differentiation of osteoblasts.

Introduction: The aim of this study was to investigate the effect of high glucose levels on proliferation and osteogenic ability in MC3T3-E1 osteoblastic cell line and to explore the regulatory mechanism of PI3 kinase (PI3K)/Akt signaling pathway. Methods: The cultures were divided into 8 treatment groups: 4 concentrations of glucose (5.5, 15.5, 25.5, and 35.5 mM) with or without LY294002. Cell proliferation, alkaline phosphatase (ALP) assay, alizarin red staining of mineralized nodule, osteogenic genes, and P-AKT expression were analyzed. Results: Cell proliferation, ALP activity, mineralization, osteogenic genes (RUNX2, OSX, OPN, OCN) and P-AKT expression in MC3T3-E1 cells were increased, whereas the glucose concentration changed from 5.5 to 15.5 mM. However, when the glucose concentrations continue to increase from 25.5 to 35.5 mM, the proliferation and osteogenic ability in MC3T3-E1 cells were gradually declined. Furthermore, these effects were significantly inhibited by PI3K/Akt inhibitor LY294002 at a glucose concentration of 15.5 mM, which was the optimum. Conclusions: Appropriate high glucose concentration (15.5 mM) can increase osteogenic differentiation by activating PI3K/Akt pathway in MC3T3-E1 cells, but exorbitant high glucose concentrations (25.5 and 35.5 mM) inhibited the biomineralization process. Findings indicated that PI3K/Akt pathway plays an important role in the physiological process of MC3T3-E1 cells.

Objective:To investigate the influence of p38MAPK inhibitor SB203580 on osteoblast MC3T3-E1 cells under high glu-cose concentration.Methods:MC3T3-E1 cells were exposed to glucose at 5.5 mmol/L,25.5 mmol/L and 25.5 mmol/L combined with SB203580 respectively.Cell proliferation was analysed by MTT assay,calcified nodules were quantitated by Alizarin Red S stai-ning.Osteogenesis gene(OCN,Runx2)mRNA level was examined by realtime PCR.Results:High glucose decreased cell prolifera-tion(P<0.05),ALP activity(P<0.05),calcified nodule formation and osteogenesis gene expression of MC3T3-E1 cells.SB203580 reversed the down-regulation of osteogenic markers under high glucose,increased the ALP expression but decreased cell proliferation. Conclusion:SB203580 is antagonistic to P38MAPK in the regulation of preliferation and differetiation of MC3T3-E1 cells.

PURPOSE The purpose of this study was to evaluate the effect of sand-blasted and acid-etched titanium surface on MC3T3-E1 murine pre-osteoblast cell differentiation, and investigate the pathway of regulating osteogenic differentiation of MC3T3-E1 cells on sand-blasted and acid-etched titanium surface in order to elucidate the regulatory mechanisms of surface roughness on osteoblastic differentiation. METHODS The characteristic of PT polished titanium (PT), sand-blasted and acid-etched (SLA) titanium surface were examined by scanning electron microscopy (SEM). Real-time PCR was applied to detect the expression of osteogenic genes including Runx2, OSX, OCN and OPN of the MC3T3-E1 cells cultured on the 2 groups of substrates.ERK1/2 activities in MC3T3-T1 cells were measured by Western blot on SLA surface. The data was analyzed using SAS9.0 software package. RESULTS The result of SEM observation showed that the PT surface was turned titanium surfaces with the mean peak to valley roughness (Ra) of 0.2 μm and the corresponding Ra value of SLA was 3.2 μm. The expression levels of Runx2, OSX, OPN and OCN were significantly higher and the cell proliferation was significantly lower on SLA surfaces than on PT surfaces (P<0.05). The expression levels of Runx2, OSX, OPN and OCN were up-regulated by the effect of SLA surface with PD98095. Compared with PT surface, ERK1/2 phosphorylation was continuously inhibited by SLA. Moreover, PT surfaces treated with PD98095 and SLA surfaces without PD98095 both demonstrated reduced ERK1/2 phosphorylation of the cells and the inhibitive effect of SLA surfaces was milder than that of PD98095. CONCLUSIONS Surface roughness is an important factor that determines osteoblast behaviors. Surface roughness of titanium substrates seems to enhance the osteoblastic differentiation of MC3T3-E1 cells and the enhancing effect of surface roughness on cell differentiation may be mediated by suppressing the activity of ERK1/2 pathway.

Objective:To observe the influence of different concentration of glucose on proliferation,differentiation and F-actin cytoskeleton of MC3T3-E1 cells,and explore the mechanism of poor implant osteointegration in high glucose concentration.Methods:Trials are divided into three glucose concentrations(5.5mmol/L,8mmol/L,12mmol/L).MTT assay was used to detect the number of the osteoblasts at 1d,3d,5d.The activity of alkaline phosphatase(ALP)was used to detect the differentiation of MC3T3-E1 cells at 1d,3d,5d,7d.The Alizarin red dye was used to observe the number of calcium nodus at 14 d,21d.The F-actin cytoskeleton were evaluated by CLSM observation at12 h.Results:Along with the increased glucose concentrations,there was significant decrease of cell numbers.ALP activity and calcium nodus.About the cytoskeleton observation,along with the increased glucose concentrations,the shape of cytoskeleton from spindle and irregular polygon to round and bristle like look changes.Meanwhile F-actin become more fuzzy and disorderly.Conclusion:Our work confirmed that high glucose concentrations significantly inhibited the proliferation,ALP activity,mineralization and F-actin cytoskeleton of MC3T3-E1 cells.

Objective: To evaluate the effect of different concentrations Concentrate Growth Factors extract (CGF e) on proliferation and differentiation of osteoblasts. Methods: Trials are divided into two experi-mental groups and the control group. Experimental groups use the α-MEM containing 10% CGF e and 20% CGF e respectively, while group (D) just use the α-MEM. MTT assay to detect the number of the osteoblasts at 1d、3d、5d; the activity of alkaline phosphatase (ALP) to detect the differentiation of os-teoblast at 3d、5d、7d; the level of osteogenetic biomarkers RUNX2 and OSX at 3d、7d were quantified by real-time PCR. Results:MTT assay indicated that at 1d、3d、5d,both the 10%CGF e and 20%CGF e have a significant increase of absorbance, the most higher increase was 20% CGF e group (P<0.05);ALP activity showed that at 3d、5d、7d, the highest absorbance was 20% CGF e group, the absorbance of 10% and 20% CGF e group were significant higher than control group (P<0.05). Realtime PCR: As the standardization in the group, the gene expression level of control group were defined as 1,the RUNX2 and OSX gene expression in experimental group are larger than control group, the highest gene expression was 20% CGF e group. Conclusions: Our work confirmed that CGF e is useful in stimulat-ing the proliferation and differentiation of osteoblasts. The 20% CGF e showed higher effect on os-teoblast than 10%CGF e.