The association between plain water intake and periodontitis in the population aged over 45: a cross-sectional study based on NHANES 2009-2014.

BACKGROUND: Numerous studies have demonstrated the impact of beverage consumption on overall health and oral health. Specifically, high consumption of sugar-sweetened beverages and coffee has been associated with an increased risk of metabolic disorders and periodontitis. Conversely, high intake of plain water has been linked to various health benefits, including weight management and reduced energy intake. However, no previous studies have explored the potential association between plain water intake and the risk of periodontitis. OBJECTIVES: Our objective was to investigate the relationship between plain water consumption and periodontitis in a middle-aged and elderly population. METHODS: The present cross-sectional study was conducted among participants aged ≥ 45 in the 2009-2014 National Health and Nutrition Examination Surveys. Multivariable regression analysis, subgroup analysis and smooth fitting tests were conducted to explore the independent relationship between plain water intake and periodontitis. RESULTS: A total of 5,882 participants were enrolled,62.02% have periodontitis. Periodontitis patients have lower plain water intake. The multivariable regression tests showed that the risk of periodontitis decreased with increased plain water intake quartiles (Q4 OR = 0.78; 95%CI 0.62-0.96) after fully adjustment. Subgroup analysis and interaction tests showed that gender, age, smoking, diabetes, hypertension or BMI does not significantly interact with the association. However, the relation was significant in males (Q4 OR = 0.64; 95%CI 0.47-0.86) but not in females (Q4 OR = 0.97;95% CI 0.71-1.31). In the smoothed curve fits stratified by gender, the curve for male participants displayed as a U-shape, with an optimal plain water intake at 1200 ml/day. For males drinking plain water less than 1200 ml/day, the risk of periodontitis decreased by 24% with each increase of 500 ml plain water intake (OR = 0.76, 95%CI 0.66-0.87, p < 0.001). CONCLUSIONS: Together, the results showed that plain water intake is negatively associated with periodontitis risk in US middle aged and elderly population. Further studies are needed to investigate the mechanism unites this association. Attention should be given to adequate plain water intake when considering dietary suggestions to the population at high risk of developing periodontitis, especially for men.

A novel porous hydroxyapatite scaffold (pHAMG) enhances angiogenesis and osteogenesis around dental implants by regulating the immune microenvironment.

OBJECTIVE: The purpose was to evaluate whether a novel porous hydroxyapatite (HA) scaffold with a 25-30-µm groove structure (pHAMG) may improve bone osteogenesis, angiogenesis, and bone integration of titanium dental implants in animal models. METHODS: The pHAMG was prepared by chemical precipitation method and its elemental composition and crystal structure were evaluated. The ability of the scaffolds to induce ectopic osteogenesis and the ability of scaffolds combined with titanium dental implants to induce orthotopic peri-implant angiogenesis, osteogenesis, and osteointegration were tested after implantation into the femur muscle pocket in rats and the mandibular defects in beagle dogs, respectively. The elemental composition was evaluated by SEM-EDS; the expression of the relevant osteogenic/inflammation marker and the anti-/pro-inflammation markers was evaluated by immunostaining and immunofluorescence, respectively. RESULTS: In animal experiments with ectopic and peri-implant osteogenesis, pHAMG resulted in significantly larger neovascularization by hematoxylin-eosin staining, as well as deposition of collagen fibers by Masson staining than HA. Meanwhile, microgrooves in pHAMG upregulate more bone morphogenetic protein (BMP) 2 and interleukin-4 (IL-4) and -10 (IL-10) and downregulate more IL-1ß and tumor necrosis factor-α (TNF-α) than that in HA. The pHAMG showed greater expression of arginase (Arg)-1 and lower expression of inducible nitric oxide synthase (iNOS) than HA. CONCLUSION: The novel pHAMG can better repair bone defects in ectopic and orthotopic model. It also transfers macrophages to anti-inflammatory phenotypes, promoting angiogenic and osteogenesis in scaffolds, and bone integration in implants. CLINICAL RELEVANCE: The novel pHAMG induce greater osteogenesis and angiogenesis which could be utilized in the clinical treatment.

ADCY6 is a potential prognostic biomarker and suppresses OTSCC progression via Hippo signaling pathway.

Oral tongue squamous cell carcinoma (OTSCC) is a malignant tumor. Recently, studies have found that adenylate cyclase 6 (ADCY6) plays a pivotal role in many lethal tumors formation processes. The role of ADCY6 in OTSCC remains unknown. The expression of ADCY6 in OTSCC tissue samples was detected. The clinical significance of ADCY6 in OTSCC was analyzed by statistical methods. OTSCC cell lines were selected to analyze the biological function of ADCY6. Meanwhile, the effect of ADCY6 on the growth of OTSCC in vivo was explored using subcutaneous tumorigenesis assay. WB assay was used to detect the underlying signaling pathway. Cell function recovery test used to investigate the mechanism of ADCY6-promoting OTSCC malignant biological behavior via Hippo signaling pathway. We report that ADCY6 was obviously downregulated in OTSCC tissue samples and cell lines. Importantly, lower expression of ADCY6 indicates a poorer prognosis in patients with OTSCC, and its expression is significantly correlated with TNM stage and tumor size. Functionally, forced expression of ADCY6 can significantly inhibit the proliferation, migration, invasion, and promote apoptosis of OTSCC cells. Mechanistically, we demonstrated that ADCY6 upregulation impaired Hippo signaling pathway to reduce the malignant biological behavior of OTSCC. Generally, our findings suggest that ADCY6 suppressed Hippo signaling pathway to regulate malignant biological behavior in OTSCC, which provide new cues for further exploring the mechanism of occurrence and development of OTSCC.

Bone marrow mesenchymal stem cell-derived exosomes loaded with miR-26a through the novel immunomodulatory peptide DP7-C can promote osteogenesis.

PURPOSE: As small bioactive molecules, exosomes can deliver osteogenesis-related miRNAs to target cells and promote osteogenesis. This study aimed to investigate miR-26a as a therapeutic cargo to be loaded into bone marrow stromal cell exosomes through a novel immunomodulatory peptide (DP7-C). METHODS: After transfecting BMSCs with DP7-C as a transfection agent, exosomes were extracted by ultracentrifugation from the culture supernatant of miR-26a-modified BMSCs. We then characterized and identified the engineered exosomes. The effect of the engineered exosomes on osteogenesis was then evaluated in vitro and in vivo, including transwell, wound healing, modified alizarin red staining, western blot, real-time quantitative PCR, and experimental periodontitis assays. Bioinformatics and data analyses were conducted to investigate the role of miR-26a in bone regeneration. RESULTS: The DP7-C/miR-26a complex successfully transfected miR-26a into BMSCs and stimulated them to release more than 300 times the amount of exosomes overexpressing miR-26a compared with the ExoNC group. Furthermore, exosomes loaded with miR-26a could enhance proliferation, migration, and osteogenic differentiation of BMSCs in vitro compared with the ExoNC and blank groups. In vivo, the ExomiR-26a group inhibited the destruction of periodontitis compared with the ExoNC and blank groups, as revealed by HE staining. Micro-CT indicated that treatment of ExomiR-26a increased the percent bone volume and the bone mineral density compared with those of the ExoNC (P < 0.05) and blank groups (P < 0.001). Target gene analysis indicated that the osteogenic effect of miR-26a is related to the mTOR pathway. CONCLUSION: miR-26a can be encapsulated into exosomes through DP7-C. Exosomes loaded with miR-26a can promote osteogenesis and inhibit bone loss in experimental periodontitis and serve as the foundation for a novel treatment strategy.

miR-210-3p suppresses osteogenic differentiation of MC3T3-E1 by targeting brain derived neurotrophic factor (BDNF).

BACKGROUND AND OBJECTIVE: As an important mediator of intercellular interaction and formation of extracellular bone matrix, porous scaffolds are widely used for bone regeneration. Accumulating evidences demonstrate that microRNA are involved in the regulation of scaffolds-induced bone regeneration. Recently, we revealed that miR-210-3p was highly expressed during osteogenesis induced by HAG. In present study, we further explored the molecular mechanism underlying the effect of miR-210-3p on osteogenic differentiation. MATERIALS AND METHODS: In this study, miR-210-3p mimics and inhibitors were synthesized and transfected into MC3T3-E1 cells to explore their effects on osteogenic differentiation. The expression of osteogenic marker (Alp and Runx2) were detected by real-time quantitative PCR (qRT-PCR) and western blotting. After osteogenesis induction for 7 days, Alp staining were used to detected osteoblast differentiation of MC3T3-E1 cells. CCK8 and Transwell assays were performed to detected cell proliferation and migration. Then, top ranking list of target genes of miR-210-3p obtained from TargetScan and the expression of BDNF were detected by qRT-PCR and ELISA. The relationship between miR-210-3p and BDNF was verified by luciferase report assay. Furthermore, the effect of BDNF on osteoblast differentiation was verified by transfecting siRNA or adding BDNF to the culture medium. RESULTS: MiR-210-3p mimics markedly suppress osteogenic differentiation, cell migration and cell proliferation of MC3T3-E; nevertheless, silencing of miR-210-3p dramatically enhanced MC3T3-E1 osteogenesis, cell migration and proliferation. Furthermore, luciferase reporter assay verified that brain derived neurotrophic factor (BDNF) is a directly target of miR-210-3p. Moreover, BDNF siRNA significantly decreased the expression levels of ALP and cell migration. The addition of BDNF partially rescued the inhibition of osteogenesis by miR-210-3p. CONCLUSION: miR-210-3p inhibited the osteogenic differentiation via targeting BDNF. Our Results provide a promising target for regulating osteogenic differentiation.

Differential Expression Profiling of microRNAs in Human Placenta-Derived Mesenchymal Stem Cells Cocultured with Grooved Porous Hydroxyapatite Scaffolds.

Scaffold materials used for bone defect repair are often limited by osteogenic efficacy. Moreover, microRNAs (miRNAs) are involved in regulating the expression of osteogenic-related genes. In previous studies, we verified the enhancement of osteogenesis using a grooved porous hydroxyapatite scaffold (HAG). In the present study, we analyzed the contribution of HAG to the osteogenic differentiation of human placenta-derived mesenchymal stem cells (hPMSCs) from the perspective of miRNA differential expression. Furthermore, results showed that miRNAs were differentially expressed in the osteogenic differentiation of hPMSCs cocultured with HAG. In detail, 16 miRNAs were significantly upregulated and 29 miRNAs were downregulated with HAG. In addition, bioinformatics analyses showed that the differentially expressed miRNAs were enriched in a variety of biological processes, including signal transduction, cell metabolism, cell junctions, cell development and differentiation, and that they were associated with osteogenic differentiation through axon guidance, mitogen-activated protein kinase, and the transforming growth factor beta signaling pathway. Furthermore, multiple potential target genes of these miRNAs were closely related to osteogenic differentiation. Importantly, overexpression of miR-146a-5p (an upregulated miRNA) promoted the osteogenic differentiation of hPMSCs, and miR-145-5p overexpression (a downregulated miRNA) inhibited the osteogenic differentiation of hPMSCs.

Targeting Autophagy with Natural Compounds in Cancer: A Renewed Perspective from Molecular Mechanisms to Targeted Therapy.

Natural products are well-characterized to have pharmacological or biological activities that can be of therapeutic benefits for cancer therapy, which also provide an important source of inspiration for discovery of potential novel small-molecule drugs. In the past three decades, accumulating evidence has revealed that natural products can modulate a series of key autophagic signaling pathways and display therapeutic effects in different types of human cancers. In this review, we focus on summarizing some representative natural active compounds, mainly including curcumin, resveratrol, paclitaxel, Bufalin, and Ursolic acid that may ultimately trigger cancer cell death through the regulation of some key autophagic signaling pathways, such as RAS-RAF-MEK-ERK, PI3K-AKT-mTOR, AMPK, ULK1, Beclin-1, Atg5 and p53. Taken together, these inspiring findings would shed light on exploiting more natural compounds as candidate small-molecule drugs, by targeting the crucial pathways of autophagy for the future cancer therapy.

A Peptide-Based Small RNA Delivery System to Suppress Tumor Growth by Remodeling the Tumor Microenvironment.

MicroRNAs can regulate a variety of physiological and pathological processes and are increasingly recognized as being involved in regulating the malignant progression of cancer, which is an important direction for the study and treatment of cancer. In addition, the tumor microenvironment has gradually become an important direction of study for combating cancer. Researchers can inhibit tumor growth by remodeling and suppressing an immunosuppressive phenotype in the tumor microenvironment. Therefore, the combination of microRNA delivery and tumor microenvironment remodeling may be a potential research direction. In a previous study, we developed a novel cationic and hydrophilic antimicrobial peptide, DP7, by computer simulation. It was found that cholesterol-modified DP7 (DP7-C) has dual functions as a carrier and an immune adjuvant. In this experiment, we used DP7-C to deliver microRNAs or inhibitors intratumorally, where it played a dual role as a carrier and an immune adjuvant. As a delivery vector, DP7-C has more advantages in terms of transfection efficiency and cytotoxicity than Lipo2000 and PEI25K. Components of the DP7-C/RNA complex can effectively escape endosomes after uptake via caveolin- and clathrin-dependent pathways. As an immune adjuvant, DP7-C can activate dendritic cells and promote macrophage polarization. Moreover, it can transform the immunosuppressive tumor microenvironment into an immune-activated tumor microenvironment, indicating its potential as an anticancer therapy. In conclusion, this study identifies a novel microRNA and inhibitor delivery system that can remodel the tumor microenvironment and introduces an alternative scheme for antitumor treatment.

Grooved hydroxyapatite scaffold modulates mitochondria homeostasis and thus promotes osteogenesis in bone mesenchymal stromal cells.

Hydroxyapatite scaffolds (HASs) are widely studied as suitable materials for bone replacement scaffolds due to their chemical similarities to organic materials. In our previous study, a novel HAS with a 25­30­µm groove structure (HAS­G) exhibited enhanced osteogenesis of bone mesenchymal stromal cells (BMSCs) compared with HAS, potentially by modulating the macrophage­induced immune microenvironment. However, the exact effects of different surface patterns on the physiological processes of attached cells is not known. The present study aimed to determine the effects of HAS­G on the osteogenesis and physiological processes in BMSCs. Cell counting kit­8 assays and propidium iodide staining followed by flow cytometry were performed, and the results demonstrated that both in normal medium and differentiating medium, HAS­G promoted cell proliferation by decreasing the proportion of G1/G0 cells and decreased reactive oxygen species (ROS) accumulation in BMSCs compared with HAS. Detection markers of osteogenesis revealed that compared with HAS, HAS­G increased runt­related transcription factor 2, osteocalcin and osteopontin protein levels and promoted osteogenesis, which was further confirmed by Alizarin Red S staining. Following JC­1 staining, it was observed that HAS­G maintained the mitochondrial membrane potential, similar to that achieved by N­acetylcysteine pretreatment. In addition, compared with those of HAS, HAS­G decreased mitochondrial ROS levels, which potentially contributed to the promotion of osteogenesis. The results also demonstrated that HAS­G inhibited mitophagy induced by ROS accumulation and ATP synthesis compared with HAS. In conclusion, HAS­G decreased ROS accumulation and mitophagy and thus promoted osteogenesis of BMSCs, indicating that ROS modulation of HAS­G may serve a key role in osteogenesis.

Impact of Hyperbaric Oxygen on the Healing of Teeth Extraction Sockets and Alveolar Ridge Preservation.

OBJECTIVES: The purpose of this study was to investigate the role of hyperbaric oxygen (HBO) in the healing of teeth extraction sockets and in alveolar ridge preservation. This may provide an experimental basis for the widespread application of HBO in oral implantation. METHODS: A total of 32 beagle dogs were included in the study and randomly divided equally between an HBO group treated with hyperbaric oxygen (100% O2, 2.4 atm, 90 min/day, 5 times/week, 6 weeks) and a normobaric oxygen (NBO) group treated with normal air in the same chamber. The lateral incisors of the maxillary and mandible of each dog were extracted, and the right upper and lower incisor extraction sockets (A2C2) were allowed to heal naturally, while left upper and lower incisor sockets (B2D2) received implants of a commercial bone substitute. At 4 and 8 weeks after surgery, clinical observation, cone-beam computerized tomography (CBCT), histomorphology observation, and expression levels of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) were analyzed to evaluate new bone formation, mineralization, and reconstruction. RESULTS: After 4 and 8 weeks, bone width and lip contour of the extraction socket in the NBO group were significantly reduced and collapsed in comparison with the HBO group. CBCT showed that the difference in vertical height between the alveolar crest of the labial tongue and palatal side of the extraction sockets was smaller in the HBO than NBO group. There was a significant difference in new bone formation (P < 0.05) and bone mineral density (P < 0.05) between the HBO and NBO groups, and the HBO group showed significantly greater new bone and bone reconstruction based on histology. Furthermore, the expression levels of VEGF and BMP-2 were higher in the HBO group. CONCLUSION: HBO reduced bone resorption and promoted early bone formation, bone mineralization, and reconstruction in the extraction sockets. HBO greatly reduced the healing time of the extraction sockets and promoted alveolar ridge preservation, thus showing promise for the clinic.

Groove structure of porous hydroxyapatite scaffolds (HAS) modulates immune environment via regulating macrophages and subsequently enhances osteogenesis.

Researches have revealed the vital roles of the generated immune environment via the response of immune cells growing on biomaterial surfaces in the bone healing process. HAS and novel constructed microgrooved patterns of HAS (HAS-G) are widely used as biocompatible ceramic, especially as a mimic of the natural bone matrix. However, it is unclear whether osteoimmune response induced by HAS and HAS-G affects the osteogenic differentiation of bone marrow stromal cells (BMSCs). RAW264.7 cells were seeded on different surface of materials and cytokines released by macrophages were detected by enzyme-linked immunosorbent assay. The cell viability and mitochondrial function of macrophages seeded on different surface of materials were detected. Then, the effects of modified inflammatory microenvironment by macrophages on osteogenesis of BMSCs were measured by performing ALP staining, Alizarin Red S staining, and western blot. We confirmed that HAS-G is more favorable for RAW cell attaching and subsequently regulated the expression and release of cytokines/chemokines. Decrease in interleukin-6 (IL-6) release was further confirmed for contributing significantly to improve mitochondrial function in RAW cells. HAS-G-conditioned medium promoted osteogenic differentiation in BMSCs and was reversed by IL-6 addition. Decrease in IL-6 contributes to downregulation of miR-214 and subsequently upregulated p38/JNK pathway, which is potentially contributes to osteogenic promotion by HAS-G. This study is the first report to reveal the effects of HAS-G on osteogenesis via immune response, which could lead to a new insight into novel material for the advantage of biomaterials for tissue engineering applications.

Multilayered pore-closed PLGA microsphere delivering OGP and BMP-2 in sequential release patterns for the facilitation of BMSCs osteogenic differentiation.

Bone tissue regeneration may be more effectively administrated by controlled release of multiple biofactors, given that bone healing comprises a cascade of biological events controlled by numerous cytokines and growth factors (GFs). Here, we propose a novel microcarrier with the capability to sequentially deliver dual biofactors for better controlling the bone regeneration process. First, osteogenic growth peptide (OGP) was incorporated in porous poly(lactic-co-glycolic) acid (PLGA) microspheres by a simple solution dipping method and subsequent pore-closing treatment. Then, a multilayered polyelectrolyte coating ((HA-CS)2 -Hep-BMP-2-Hep-(CS-HA)2 ) was prepared on the surface of such OGP-loaded pore-closed PLGA microspheres by layer-by-layer assembly. Results showed that the OGP release was minimal (<17.1%) in the first 15 days but accelerated remarkably thereafter, while at least 60.3% of the bone morphogenetic protein-2 (BMP-2) load was released in the first 15 days and only very slow release was observed subsequently. Further in vitro cell experiments showed that the dual-biomolecule-loaded microspheres elicited more cells with extremely elongated cellular morphology, much higher alkaline phosphatase level and upregulated expression of osteocalcin. Such a dual loading of OGP and BMP-2 had a more positive impact on bone marrow mesenchymal stem cells proliferation and osteogenic differentiation compared with either OGP or BMP-2 alone, suggesting potential synergistic benefit of the sequential release of multiple peptide-based biofactors in a coordinated manner. Overall, this dual delivery system may provide a therapeutic strategy sequentially targeting multiple events (or mechanisms) during bone healing, which is believed to benefit the regenerative repair of bone defects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 95-105, 2018.

Effective inhibition of melanoma tumorigenesis and growth via a new complex vaccine based on NY-ESO-1-alum-polysaccharide-HH2.

BACKGROUND: A safe and effective adjuvant plays an important role in the development of a vaccine. However, adjuvants licensed for administration in humans remain limited. Here, for the first time, we developed a novel combination adjuvant alum-polysaccharide-HH2 (APH) with potent immunomodulating activities, consisting of alum, polysaccharide of Escherichia coli and the synthetic cationic innate defense regulator peptide HH2. METHODS: The adjuvant effects of APH were examined using NY-ESO-1 protein-based vaccines in prophylactic and therapeutic models. We further determined the immunogenicity and anti-tumor effect of NY-ESO-1-APH (NAPH) vaccine using adoptive cellular/serum therapy in C57/B6 and nude mice. Cell-mediated and antibody-mediated immune responses were evaluated. RESULTS: The APH complex significantly promoted antigen uptake, maturation and cross-presentation of dendritic cells and enhanced the secretion of TNF-α, MCP-1 and IFN-γ by human peripheral blood mononuclear cells compared with individual components. Vaccination of NAPH resulted in significant tumor regression or delayed tumor progression in prophylactic and therapeutic models. In addition, passive serum/cellular therapy potently inhibited tumor growth of NY-ESO-1-B16. Mice treated with NAPH vaccine produced higher antibody titers and greater antibody-dependent/independent cellular cytotoxicity. Therefore, NAPH vaccination effectively stimulated innate immunity, and boosted both arms of the adaptive humoral and cellular immune responses to suppress tumorigenesis and growth of melanoma. CONCLUSIONS: Our study revealed the potential application of APH complex as a novel immunomodulatory agent for vaccines against tumor refractory and growth.

Adenoviral vectors modified by heparin-polyethyleneimine nanogels enhance targeting to the lung and show therapeutic potential for pulmonary metastasis in vivo.

Polyethyleneimine (PEI) is a well-known cationic polymer that has previously been shown to have significant potential to deliver genes in vitro and in vivo. However, PEI is non-degradable and exhibits a high cytotoxicity as its molecular weight increases. The clinical application for systemic administration of adenoviral (Ad) vectors is limited, as these vectors do not efficiently penetrate solid tumor masses due to a common deficiency of Coxsackie Adenovirus Receptor (CAR) on the tumor surface. In this study, we conjugated low molecular weight PEI (Mn = 1,800) to heparin (Mn = 4,000-6,000) to create a new type of cationic degradable nanogel (HPEI) that was then used to modify Ad vectors. The resulting HPEI-Ad complexes were used to infect CT26 and HeLa cells in vitro. Additionally, the HPEI-Ad complexes were administrated in vivo via intravenous injection, and tissue distribution was assessed using luciferase assays; the therapeutic potential of HPEI-Ad complexes for pulmonary metastasis mediated by CT26 cells was also investigated. In vitro, HPEI-Ad complexes enhanced the transfection efficiency in CT26 cells, reaching 36.3% compared with 0.1% of the native adenovirus. In vivo, HPEI-Ad complexes exhibited greater affinity for lung tissue than the native adenovirus and effectively inhibited the growth of pulmonary metastases mediated by CT26 cells. Our results indicate that Ad vectors modified by HPEI nanogels to form HPEI-Ad complexes enhanced transfection efficiency in CT26 cells that lacked CAR, targeted to the lung and demostrated a potential therapy for pulmonary metastasis.

Immortalized mouse floxed Bmp2 dental papilla mesenchymal cell lines preserve odontoblastic phenotype and respond to BMP2.

Bone morphogenetic protein 2 (Bmp2) is essential for odontogensis and dentin mineralization. Generation of floxed Bmp2 dental mesenchymal cell lines is a valuable application for studying the effects of Bmp2 on dental mesenchymal cell differentiation and its signaling pathways during dentinogenesis. Limitation of the primary culture of dental mesenchymal cells has led to the development of cell lines that serve as good surrogate models for the study of dental mesenchymal cell differentiation into odontoblasts and mineralization. In this study, we established and characterized immortalized mouse floxed Bmp2 dental papilla mesenchymal cell lines, which were isolated from 1st mouse mandibular molars at postnatal day 1 and immortalized with pSV40 and clonally selected. These transfected cell lines were characterized by RT-PCR, immunohistochemistry, and analyzed for alkaline phosphatase activity and mineralization nodule formation. One of these immortalized cell lines, iBmp2-dp, displayed a higher proliferation rate, but retained the genotypic and phenotypic characteristics similar to primary cells as determined by expression of tooth-specific markers as well as demonstrated the ability to differentiate and form mineralized nodules. In addition, iBmp2-dp cells were inducible and responded to BMP2 stimulation. Thus, we for the first time described the establishment of an immortalized mouse floxed Bmp2 dental papilla mesenchyma cell line that might be used for studying the mechanisms of dental cell differentiation and dentin mineralization mediated by Bmp2 and other growth factor signaling pathways.

[Relationship between the infiltration arts and penetration depth of molten glass into aluminum oxide matrix].

OBJECTIVE: To explore the influences of infiltration time and temperature on the penetration depth of GI-II glass into alumina matrices, thus providing a theoretical basis for facilitating the clinical fabrication of all-ceramic restorations. METHODS: After preparing cuboid alumina specimens 7 x 7 x 5 mm3 in size, we carried out the infiltration firing procedure at 1100 degrees C for six different time duration (30, 60, 90, 120, 150, 180 minutes), and at five different temperatures (1060, 1080, 1100, 1120, 1140 degrees C) for 1 hour each. The penetration depth of glass into the alumina matrices was measured under a stereoscope with magnification of 10 times. RESULTS: The infiltration time duration and penetration depth were not linearly but exponentially related for both Vita and GI-II materials (r = 0.9886 for Vita and r = 0.9932 for GI-II). The regression equations were as follows: d2 = 0.1122t - 0.4955 (Vita) and d2 = 0.1638t + 0.5873 (GI-II). The temperature and depth were not linearly related either, with increased penetration speed under higher temperatures for GI-II material; the tendency for Vita material was just the opposite. CONCLUSION: At an infiltration temperature of 1100 degrees C, the molten infiltration time duration of GI-II glass could be reduced to 1 hour for copings and 3 hours for anterior bridge substructures due to its better infiltration ability.